Showing posts with label GABAA α5. Show all posts
Showing posts with label GABAA α5. Show all posts

Thursday, 21 September 2023

Big heads, the Car wash, Transcranial pulse stimulation, GABA alpha 5 and Potassium channel Kv3.1

Today’s post is a review of some interesting new research that relates to the scope of this blog.  It ranges from training young people with autism/ID to work at the car wash, to more complex science.

Let’s start with the easiest paper. Somewhat bizarrely it was carried out in Japan by researchers from India. I am a fan of teaching kids to wash cars but I was surprised to see that it would be covered in a published research study.

One often forgotten item to teach teenagers and young adults with autism or ID is how to safely use public transport, so they might travel independently to and from any future job. We have had a lot of success with this recently. Monty, now aged 20, can get all the way from home to various different locations across the city using public transport, including changing buses and with journey times more than one hour.


Increasing car washing competency in adolescents with autism and intellectual disabilities: Researching visual task evaluation

This study looked at how well visual task evaluation helped teenagers with autism and intellectual disabilities become more competent at car washing. For disabled people to promote their independence and employment chances, car washing skills are crucial. The goal of this study was to ascertain whether training techniques that include visual task evaluation can improve car washing proficiency in teenagers with autism and intellectual disabilities. 30 participants, ranging in age from 12 to 18, participated in a pre-test/post-test design. Randomly chosen groups of participants were put into the evaluation group for the visual task or the control group. According to the findings, the visual task evaluation group outperformed the control group in terms of car washing ability. Adolescents with autism and intellectual disabilities can learn skills more quickly and become more independent by including visual task evaluation into their teaching strategies. These results demonstrate the potential for such treatments to enhance their quality of life and employment chances.


Car washing with a pressure washer is great fun for most people and washing a car thoroughly has many individual steps to master, so it is good practice.


Head size

It has been known for decades that big heads (macrocephaly) and small heads (microcephaly) are a tell-tale sign of a neurodevelopment problem. Normally, big heads are linked to intellectual disability, but very small heads are also a warning sign.

Readers may recall the Zika virus epidemic in Brazil in 2015. This mosquito-borne virus caused pregnant women to give birth to children with microcephaly. Zika virus infection caused intellectual disability in babies. The severity of the intellectual disability varied from mild to severe. Babies with Zika virus infection may have difficulty learning and communicating. They may also have problems with problem-solving and abstract thinking. Hearing and vision can be impaired and growth is retarded.  

Head size parts autism into two major subtypes

Essentially opposite paths in fetal brain development may explain two major subtypes of autism. In one of these subtypes, an unusually high number of excitatory neurons in a key brain region leads to large heads, or macrocephaly, which affects roughly 20 percent of people with autism; in the other, a decreased number of the same cells in that area leads to more typical head sizes, a new study finds. 

This fundamental biological difference suggests that “therapeutic avenues may be drastically different for these subtypes,” says lead investigator Flora Vaccarino, professor of neuroscience at Yale University. “That in turn could explain why drug treatments for autism so far are failing.”


The opposite brain development paths found in this research may both lead to autism because they are each a case of imbalance, says investigator Alexej Abyzov, associate professor of biomedical informatics at the Mayo Clinic in Rochester, Minnesota. 

The full paper:- 

Modeling idiopathic autism in forebrain organoids reveals an imbalance of excitatory cortical neuron subtypes during early neurogenesis

Idiopathic autism spectrum disorder (ASD) is highly heterogeneous, and it remains unclear how convergent biological processes in affected individuals may give rise to symptoms. Here, using cortical organoids and single-cell transcriptomics, we modeled alterations in the forebrain development between boys with idiopathic ASD and their unaffected fathers in 13 families. Transcriptomic changes suggest that ASD pathogenesis in macrocephalic and normocephalic probands involves an opposite disruption of the balance between excitatory neurons of the dorsal cortical plate and other lineages such as early-generated neurons from the putative preplate. The imbalance stemmed from divergent expression of transcription factors driving cell fate during early cortical development. While we did not find genomic variants in probands that explained the observed transcriptomic alterations, a significant overlap between altered transcripts and reported ASD risk genes affected by rare variants suggests a degree of gene convergence between rare forms of ASD and the developmental transcriptome in idiopathic ASD.


Head circumference at birth is a useful measurement, but what really matters is how it changes over time.  Hyperactive pro-growth signaling affects more than just brain growth, it also affects muscle development, which is easy to notice.  I have highlighted the graphic below several times in this blog and in my book.  It is a good summary of what is going on.



Regular readers will know that I like ion channels. The reason is that dysfunctions in these channels really should be treatable.  Usually we are looking for channel blockers, but today with Kv3.1 we are looking for channel enhancers.

Ion channel enhancers increase the activity of ion channels without directly opening them. They do this by increasing the number of open channels, increasing the opening time of each channel, or decreasing the closing time of each channel.


At the heart of the study is a type of inhibitory neuron called GABAergic interneurons, which connect brain regions, playing vital roles in coordinating high-frequency brain activity. As a potential source of the excitatory/inhibitory imbalance in ASD and schizophrenia, evidence now points to malfunction of a type of potassium channel, Kv3.1, special to GABAergic interneurons. Denton and his team will aim to develop Kv3.1 enhancers and test their efficacy in restoring the balance of neural activity in a mouse model of ASD. In latter stages of this work, they’ll focus on key brain areas, using various lab techniques to carefully fill in neurological details surrounding any targeted drug effects.

“This grant creates opportunities for developing critically needed tool compounds to explore the role of Kv3.1 potassium channels in autism spectrum disorder and schizophrenia,” said Denton, professor of Anesthesiology and Pharmacology. “These are some of the most challenging and costly disorders going, and we’re excited to have this opportunity to take this work forward.”


Japanese researchers from the RIKEN Brain Science Institute are also thinking along the lines of targeting Kv3.1 to “correct aberrant developmental trajectories”. 

Kv3.1 channels regulate the rate of critical period plasticity 

The emergent function of fast-spiking PV-cell circuits during postnatal life may hold the key to a deeper understanding of critical periods in brain development (Reh et al., 2020) and the etiology of related mental illnesses as well (Do KQ and Hensch, 2015). The human neocortex notably shows a decrease in Kv3.1b channel protein in schizophrenia, a deficit that is restored by anti-psychotic drugs (Yanagi et al., 2014). Moreover, individuals with a KCNC1 loss-of-function variant can present intellectual disability without seizure and epilepsy (Poirier et al., 2017Park et al., 2019). Our work points toward a prophylactic psychiatry that may target these particular channels to correct aberrant developmental trajectories.


As with head size, the “when” is also important with correcting Kv3.1.  The idea is to intervene at a very early age to redirect the developmental trajectory, rather than just to improve today’s functioning.

The logical question is what drugs will Professor Denton come up with to explore the benefit of targeting Kv3.1.  Perhaps someone can beat him to it and save us all a couple of decades?

If you look up Kv3.1 or the gene that encodes it called KCNC1 you can read all about it.


As expected, there is no shortage of channel blockers – Nifedipine (used a calcium channel blocker), Miconazole (an antifungal), Capsaicin (an active component of chili peppers), Fluoxetine (better known as Prozac, which is vitamin P to many people) plus many more.

Professor Denton is hunting for a channel enhancer.  Keep an eye on what he comes up with. He has $2.7 million over 4 years to play with. 


Transcranial pulse stimulation

Many autism parents do not like drug therapies, but often like the idea of zapping the brain from outside. I liked the idea of Photo biomodulation (PBMT) a form of light therapy that utilizes light sources including lasers or LEDs.


Low Level Laser Therapy (LLLT) for Autism – seems to work in Havana

Home/Clinic based Photobiomodulation/Laser Therapy in Autism - acting on Light Sensitive Ion Channels, Mitochondria, Lymph Nodes and more


You could potentially do Low Level Laser Therapy (LLLT) at home.

Professor Manual Casanova is a fan of transcranial magnetic stimulation (TMS).

Today’s paper below is about transcranial pulse stimulation, which I suppose we can just call TPS.

Transcranial pulse stimulation (TPS) is a non-invasive brain stimulation technique that uses pulsed electrical or magnetic fields to stimulate the brain. It is a relatively new technique, but it has the potential to be used for a variety of purposes, including:

  • Treating neurological disorders such as Parkinson's disease, Alzheimer's disease, and depression
  • Enhancing cognitive function, such as memory and attention
  • Improving mood and well-being
  • Reducing pain
  • Promoting neuroplasticity, the ability of the brain to change and adapt



Effects of transcranial pulse stimulation on autism spectrum disorder: a double-blind, randomized, sham-controlled trial


Transcranial pulse stimulation has been proven effective to improve cognition, memory and depressive symptoms of Alzheimer’s disease, but supporting evidence on other neurological diseases or neuropsychiatric disorders remains limited. This study aimed to investigate the effects of transcranial pulse stimulation on the right temporoparietal junction, which is a key node for social cognition for autism spectrum disorder, and to examine the association between transcranial pulse stimulation and executive and social functions. This double-blinded, randomized, sham-controlled trial included 32 participants (27 males), aged 12–17 years with autism spectrum disorder. All eligible participants were randomized into either the verum or sham transcranial pulse stimulation group, on a 1:1 ratio, based on the Childhood Autism Rating Scale screening score. Sixteen participants received six verum transcranial pulse stimulation sessions (energy level: 0.2–0.25 mJ/mm2; pulse frequency: 2.5–4.0 Hz, 800 pulse/session) in 2 weeks on alternate days. The remaining 16 participants received sham transcranial pulse stimulation. The primary outcome measure included Childhood Autism Rating Scale score changes, evaluated by parents, from baseline to 3-month follow-ups. Secondary outcomes included a self-reported questionnaire responded to by parents and cognitive tests responded to by participants. A licensed mental health professional evaluated clinical global impression severity, improvement, efficacy and total score. Results revealed significant interactions in Childhood Autism Rating Scale and other secondary outcomes. Significant group and time effects were found in most secondary outcomes. Additionally, significant differences were found between the transcranial pulse stimulation and sham transcranial pulse stimulation groups in Childhood Autism Rating Scale and clinical global impression improvement and total score immediately after 2 weeks of transcranial pulse stimulation intervention (all P < 0.05), and effects were sustainable at 1- and 3-month follow-up, compared with baseline. The effect size of Childhood Autism Rating Scale (d = 0.83–0.95) and clinical global impression improvement (d = 4.12–4.37) were large to medium immediately after intervention and sustained at 1-month post-stimulation; however, the effects were reduced to small at 3-month post-stimulation (d = 2.31). These findings indicated that transcranial pulse stimulation over right temporoparietal junction was effective to reduce the core symptoms of autism spectrum disorder, as evidenced by a 24% reduction in the total Childhood Autism Rating Scale score in the verum transcranial pulse stimulation group. Additionally, the clinical global impression total score was reduced by 53.7% in the verum transcranial pulse stimulation group at a 3-month follow-up, compared with the baseline. Participants in the verum transcranial pulse stimulation group had shown substantial improvement at 1- and 3-month follow-ups, compared with baseline, although some of the neuropsychological test results were deemed statistically insignificant. Future replication of this study should include a larger sample derived from multi-nations to determine transcranial pulse stimulation as an alternative top-on treatment option in neuropsychiatry


TPS looks pretty impressive, based on the above study. TPS is available today, but it does need a lot of visits to the therapist. The effects are not permanent so you would have to keep going back for more.

People are doing transcranial direct current stimulation (tDCS) at home. 

People are zapping their brains at home to improve focus and clear brain fog. But is it safe?

For any kind of zapping therapy to be viable, it would have to be possible to do it yourself at home.


Targeting alpha 5 subunit of GABAA receptors

Some earlier posts in this blog did get rather complicated.  One field that I looked at in rather painful detail was the GABAA receptor. Some readers of this blog have children whose autism is entirely caused by a defect in this receptor, many other readers just see the effects of a GABAA malfunction caused by a problem with NKCC1/KCC2 expression resulting from the GABA developmental switch failing to occur.

I looked to me that targeting alpha 3 and alpha 5 subunits could well enhance cognition.

Alpha 3 is targeted by low dose Clonazepam, thanks to Professor Catterall.

Alpha 5 was targeted to treat Down syndrome, using a new drug called Basmisanil (an inverse agonist of alpha 5 subunit of GABAA). That work failed. I wrote about Cardiazol/ Pentylenetetrazol (PTZ) a drug that was widely used in the 1930s in mental hospitals to trigger seizures that were supposed to treat people with schizophrenia.  At much lower doses, it found a new purpose decades ago as an ingredient in cough medicine. 

The alpha 5 subunit is one of several subunits that can make up a GABAA receptor. GABAA receptors containing the alpha 5 subunit are thought to be involved in cognitive function, learning and memory, and mood regulation.

PTZ has been shown to block the action of GABA at alpha 5-containing GABAa receptors in animal studies.  

Variable Expression of GABRA5 and Activation of α5 -  a Modifier of Cognitive Function in Autism?


Sodium Benzoate and GABRA5 - Raising Cognitive Function in Autism 

Cardiazol, a failed Schizophrenia treatment from the 1930s, repurposed at low doses as a Cognitive Enhancer in Down Syndrome and likely some Autism


The logical human trial would be to use the cough mixture, Cardiazole that is already used in children. 

“We actual have quite a few readers from India and that is the only other country using this drug.  In India the producer is Nicholas Piramal and the brand name is Cardiazol Dicodid, it cost 30 US cents for 10ml.  So for less than $1, or 70 rupees, you might have a few months of cognitive enhancement, that is less than some people pay for 1 minute of ABA therapy.

If a few drops of this children’s cough medicine improves cognition please lets us all know.”


Back to recent research on alpha 5 that caught my attention.


An alpha 5-GABAa receptor positive allosteric modulator attenuates social and cognitive deficits without changing dopamine system hyperactivity in an animal model for autism

 Autism Spectrum Disorders (ASD) are characterized by core behavioral symptoms in the domains of sociability, language/communication, and repetitive or stereotyped behaviors. Deficits in the prefrontal and hippocampal excitatory/inhibitory balance due to a functional loss of GABAergic interneurons are proposed to underlie these symptoms. Increasing the postsynaptic effects of GABA with compounds that selectively modulate GABAergic receptors could be a potential target for treating ASD symptoms. In addition, deficits in GABAergic interneurons have been linked to dopamine (DA) system dysregulation, and, despite conflicting evidence, abnormalities in the DA system activity may underly some ASD symptoms. Here, we investigated whether the positive allosteric modulator of α5-containing GABAA receptors (α5-GABAARs) SH-053-2’F-R-CH3 (10 mg/kg) attenuates behavioral abnormalities in a rat model for autism based on in utero VPA exposure. We also evaluated if animals exposed to VPA in utero present changes in the ventral tegmental area (VTA) DA system activity using in vivo electrophysiology and if SH-053-2’F-R-CH3 could attenuate these changes. In utero VPA exposure caused male and female rats to present increased repetitive behavior (self-grooming) in early adolescence and deficits in social interaction in adulthood. Male, but not female VPA rats, also presented deficits in recognition memory as adults. SH-053-2’F-R-CH3 attenuated the impairments in sociability and cognitive function in male VPA-exposed rats without attenuating the decreased social interaction in females. Male and female adult VPA-exposed rats also showed an increased VTA DA neuron population activity, which was not changed by SH-053-2’F-R-CH3. Despite sex differences, our findings indicate α5-GABAARs positive allosteric modulators may effectively attenuate some core ASD symptoms


Fine tuning alpha 5, perhaps you need more, perhaps less?


Neurobiology and Therapeutic Potential of α5-GABA Type A Receptors

Despite being a genetically heterogeneous disorder, the potential utility for mechanism-based GABAAR pharmacologic treatment with ASDs is supported by shared pathologies both in patients and related mouse models.


PAM α5 GABAAR Therapeutic Applications

Neurodevelopmental Disorders

Mouse models of neurodevelopmental disorders that present with insufficient inhibitory tone show improvement with positive modulators of GABAAR signaling. In the Scn1a+/− mouse model of Dravet syndrome, a severe childhood epileptic encephalopathy syndrome with hyperactivity and autism behaviors, abnormal social behaviors and fear memory deficits were rescued following treatment with a benzodiazepine, clonazepam (Han et al., 2014). In an ASD mouse model with reduced GABAAR-mediated inhibition, the BTBR T+tf/J mouse, the α2,3 and 5 PAM L-838,417, improved deficits in social interaction, repetitive behaviors, and spatial learning (Han et al., 2014).


Postweaning positive modulation of α5GABAA receptors improves autism‐like features in prenatal valproate rat model in a sex‐specific manner 

Autism spectrum disorder (ASD), as a common neurodevelopmental disorder that encompasses impairments in social communication and interaction, as well as repetitive and restrictive behavior, still awaits an effective treatment strategy. The involvement of GABAergic neurotransmission, and especially a deficit of GABA A receptors that contain the α5 subunits, were implicated in pathogenesis of ASD. Therefore, we tested MP‐III‐022, a positive allosteric modulator (PAM) selective for α5GABAA receptors, in Wistar rats prenatally exposed to valproic acid, as an animal model useful for studying ASD. Postweaning rats of both sexes were treated for 7 days with vehicle or MP‐III‐022 at two doses pharmacokinetically determined as selective, and thereafter tested in a behavioral battery (social interaction test, elevated plus maze, spontaneous locomotor activity, and standard and reverse Morris water maze). Additional rats were used for establishing a primary neuronal culture and performing calcium imaging, and determination of hippocampal mRNA levels of GABRA5, NKCC1, and KCC2. MP‐III‐022 prevented impairments in many parameters connected with social, repetitive and restrictive behavioral domains. The lower and higher dose was more effective in males and females, respectively. Intriguingly, MP‐III‐022 elicited certain changes in control animals similar to those manifested in valproate animals themselves. Behavioral results were mirrored in GABA switch and spontaneous neuronal activity, assessed with calcium imaging, and also in expression changes of three genes analyzed. Our data support a role of α5GABAA receptors in pathophysiology of ASD, and suggest a potential application of selective PAMs in its treatment, that needs to be researched in a sex‐specific manner. Lay Summary In rats prenatally exposed to valproate as a model of autism, a modulator of α5GABAA receptors ameliorated social, repetitive and restrictive impairments, and, intriguingly, elicited certain autism‐like changes in control rats. Behavioral results were mirrored in GABA switch and spontaneous neuronal activity, and partly in gene expression changes. This shows a role of α5GABAA receptors in pathophysiology of ASD, and a potential application of their selective modulators in its treatment.


Note the researchers actually know about the GABA switch and so measured mRNA levels of NKCC1 and KCC2.

Note also that the lower dose of MP‐III‐022 was more effective in males and the higher dose in females.

We even have the recent associated PhD thesis from Anja Santrač:-


The influence of positive modulation of GABAA receptors containing the alpha5 subunit on behavioral changes of mice and rats in models of autistic disorders

The role of α5 GABAA receptors in learning and memory is well known. Therefore, we decided to examine the effect of the selective positive allosteric modulator (PAM) MP-III-022 on learning and memory of healthy animals, as well as GABRA5 expression. After demonstrating the needed tolerability and potential procognitive effects, the ligand would be used in an animal model of autism spectrum disorders (ASD). ASD is a neurodevelopmental disorder that encompasses impairments in social communication and interaction, as well as repetitive and restrictive behavior, still without an effective treatment. In this context, animal models that imitate specific disease’s symptoms are an excellent tool of translational research. Some of the most frequently used models are BTBR T+ tf/J mouse strain (BTBR) and valproate prenatal model (VPA). Our experiments have shown that the variability of α5GABAA receptors’ roles depends on its level of expression and localization, on the type and protocol of cognitive tasks, the timing of testing and intensity of pharmacological modulation. Obtained results proved potential beneficial effects of MP-III-022 in cognitive tasks. The BTBR model failed to express sufficient face validity, while VPA demonstrated adequate face validity and in part construct validity. Thus, we decided to subacutely apply MP-III-022 to juvenile VPA rats. In control animals, treatment led to GABRA5 decrease and to impairments similar to ones seen in ASD, suggesting the possible role of this receptor in the pathogenesis of the disease. Most importantly, our results demonstrated the potential of α5 GABAA receptor PAMs in secondary prevention and treatment of ASD, with the caveat that the drug development program would require adaptations tailored to sex-specific differences revealed.


Good job Anja. For our Serbian speaking readers, here is the link to her thesis:-

Perhaps we should connect her with Professor Ben-Ari?



Fine tuning alpha 5 subunits of GABAA receptors really should be followed up.  I think you need both options - a little bit more and a little bit less. It did not work for Roche in Down syndrome, but the potential remains.

Kv3.1 is another focused target for research, that very likely will become actionable. 

Transcranial pulse stimulation, like all the other zapping therapies, looks interesting, but it needs to be packaged in way that can actually be implemented every day at home.

In the meantime, at least getting your kid to wash the car is something we can all do.

Thursday, 9 November 2017

Variable Expression of GABRA5 and Activation of α5 -  a Modifier of Cognitive Function in Autism?

Today’s post sounds complicated. We actually already know that the gene GABRA5, and hence the alpha 5 sub-unit of GABAA receptors, can affect cognition, but we do not know for sure in whom it is relevant.
Most readers of this blog are lay people, as such we tend to be predisposed to the idea that autism is somehow “hardwired”, something that just happened and cannot be reversed. Some of autism is indeed “hardwired”, you cannot take an adult with autism and “re-prune” his synapses, to produce a more elegant robust network in his brain. But much can be done, because many things in the brain are changing all the time, they are not fixed at all. Today’s post is good example.
GABA is the most important inhibitory neurotransmitter in the brain. There are two types of GABA receptor, A and B. These receptors are made up of sub-units. There are many different possible combinations of sub-units to make GABAA receptors. These combinations are not fixed, or “hard-wired”; they vary all the time.
The composition of the GABAA receptor changes its effect. It can change how you feel (anxiety) and it can change you think/learn.
You can actually measure GABRA5 expression in different regions of the brain in a test subject using a PET-CT (Positron Emission Tomography–Computed Tomography) scan and it has been done in some adults with high functioning autism. This machine looks like a big front-leading washing machine, just a bit cleverer. 

our primary hypothesis was that, compared to controls, individuals with ASD have a significant reduction in α5 GABA receptor availability in these areas.
Due to the small sample size, we could not examine possible correlations between GABAA binding and particular symptoms of ASD, age, IQ, or symptoms of comorbidities frequently associated with ASD, such as anxiety disorders, OCD and depression. We were also unable to address the effects of possible neuroanatomical differences between people with ASD and controls, which might lead to partial volume effects in PET studies. However, the modest magnitude of the volumetric differences seen in most studies of high-functioning ASD suggests that it is unlikely that these could fully explain the present findings.

These preliminary results suggest that potentiation of GABAA signaling, especially at GABAA α5-subunit containing receptors, might potentially be a novel therapeutic target for ASD. Unselective GABAA agonists and positive allosteric modulators, such as benzodiazepines, have undesirable features such as abuse potential and tolerance, but more selective modulators might avoid such limitations. Further research should extend this work in a larger sample of ASD individuals. It would also be interesting to use PET with the ligand [11C]Ro15-4513 to measure GABAA in disorders of known etiology characterised by ASD symptoms, such as Fragile X and 15q11-13 duplication
In summary, we present preliminary evidence of reduced GABAA α5 expression in adult males with ASD, consistent with the hypothesis that ASD is characterised by a defect in GABA signaling. 

The prevalence of autism spectrum disorders (ASDs), which affect over 1% of the population, has increased twofold in recent years. Reduced expression of GABAA receptors has been observed in postmortem brain tissue and neuroimaging of individuals with ASDs. We found that deletion of the gene for the α5 subunit of the GABAA receptor caused robust autism-like behaviors in mice, including reduced social contacts and vocalizations. Screening of human exome sequencing data from 396 ASD subjects revealed potential missense mutations in GABRA5 and in RDX, the gene for the α5GABAA receptor-anchoring protein radixin, further supporting a α5GABAA receptor deficiency in ASDs.

The results from the current study suggest that drugs that act as positive allosteric modulators of α5GABAA receptors may ameliorate autism-like behaviors 

Too many or too few the α5GABAA receptors or too much/little activity?

Regular readers will know that autism is all about extremes hypo/hyper, macro/micro etc. The same is true with α5GABAA, too few can cause autistic behaviors, but too many can impede learning. You need just the right amount.
The next variable is how well your α5GABAA are behaving, because even if you have an appropriate number of these receptors, you may not have optimal activity from them. Over activity from α5GABAA is likely to have the same effect as having too many of them.
Here it becomes very relevant to many with autism and inflammatory comorbidities, because systemic inflammation has been shown to activate α5GABAA. It has been shown that increased α5GABAA receptor activity contributes to inflammation-induced memory deficits and, by my extension, to inflammation-induced cognitive decline.

α5GABAA Receptors Regulate Inflammation-Induced Impairment of Long-Term Potentiation

Systemic inflammation causes learning and memory deficits through mechanisms that remain poorly understood. Here, we studied the pathogenesis of memory loss associated with inflammation and found that we could reverse memory deficits by pharmacologically inhibiting α5-subunit-containing γ-aminobutyric acid type A (α5GABAA) receptors and deleting the gene associated with the α5 subunit. Acute inflammation reduces long-term potentiation, a synaptic correlate of memory, in hippocampal slices from wild-type mice, and this reduction was reversed by inhibition of α5GABAA receptor function. A tonic inhibitory current generated by α5GABAA receptors in hippocampal neurons was increased by the key proinflammatory cytokine interleukin-1β through a p38 mitogen-activated protein kinase signaling pathway. Interleukin-1β also increased the surface expression of α5GABAA receptors in the hippocampus. Collectively, these results show that α5GABAA receptor activity increases during inflammation and that this increase is critical for inflammation-induced memory deficits.

We saw in an earlier post that overexpression of GABRA5 is found in slow learners and we know that this is a key target of Down Syndrome research, aimed at raising cognitive function.

What can be modified?
It appears that you can modify the expression of GABRA5, which means you can increase/decrease the number of GABAA receptors that contain an α5 subunit.
You can also tune the response of those α5 subunits. You can increase it or decrease it.
Activation of the α5 subunit is thought to be the reason why benzodiazepine drugs  have cognitive (reducing) side effects. By extension, inverse agonists of α5 are seen as likely to be nootropic.
One such drug is LS-193,268  is a nootropic drug invented in 2004 by a team working for Merck, Sharp and Dohme.
A complication is that you do not want to affect the α2 subunit, or you will cause anxiety. So you need a highly selective inverse agonist.
The new Down Syndrome drug, Basmisanil, is just such a selective inverse agonist of α5.
Basmisanil (developmental code names RG-1662, RO5186582) is a highly selective inverse agonist/negative allosteric modulator of α5 subunit-containing GABAA receptors which is under development by Roche for the treatment of cognitive impairment associated with Down syndrome.  As of August 2015, it is in phase II clinical trials for this indication.

A contradiction
As is often the case, there is an apparent contradiction, because on the one hand a negative allosteric modulator should be nootropic in NT people and appears to raise cognition in models of Down Syndrome; but on the other hand results from a recent study suggests that drugs that act as positive allosteric modulators of α5GABAA receptors may ameliorate autism-like behaviors.
So which is it?
Quite likely both are right.
It is exactly as we saw a long while back with NMDAR activity, some people have too much and some have too little. Some respond to an agonist, some to an antagonist and some to neither.
What we can say is that fine-tuning α5GABAA in man and mouse seems a viable option to enhance cognition in those with learning difficulties.
The clever option is probably the positive/negative allosteric modulator route, the one being pursued by big Pharma for Down Syndrome.
I like Dr Pahan’s strategy from this previous post, for poor learners and those with early dementia

to use cinnamon/NaB to reduce GABRA5 expression, which has got to consequently reduce α5GABAA activity.
All of these strategies are crude, because what matters is α5GABAA activity in each part of the brain. This is why changing GABRA5 expression will inevitably have good effects in one area and negative effects in another area. What matter is the net effect, is it good, bad or negligible?
The fact that systemic inflammation increases α5GABAA activity may contribute to the cognitive decline some people with autism experience.
We previously saw how inflammation changes KCC2 expression and hence potentially increases intra cellular chloride, shifting GABA towards excitatory.
Ideally you would avoid systemic inflammation, but in fact all you can do is treat it.
Increasing α5GABAA activity I would see as possible strategy for people with high IQ, but some autistic features.
I think those with learning problems are likely to be the ones wanting less α5GABAA activity.
The people for whom “bumetanide has stopped working” or “NAC has stopped working” are perhaps the ones who have developed systemic inflammation for some reason.  You might only have to measure C-reactive protein (CRP) to prove this.

More reading for those interested:-

Wednesday, 4 October 2017

Sodium Benzoate and GABRA5 - Raising Cognitive Function in Autism

I am still looking for additional cognitive enhancing autism therapies. It seems the best way to find them may actually be to reread my own blog.
A long time ago I suggested that Cinnamon could well be therapeutic in autism, most likely (but not entirely) due to the sodium benzoate (NaB) it produces in your body.

Sodium benzoate (NaB) is both a drug used to reduce ammonia in your blood and a common food additive that acts as a preservative.
NaB has many biological effects.  One effect relates to a protein called DJ-1, which is produced by a Parkinson’s gene (PARK7). I had noticed that when the body tries to turn on its anti-oxidant genes after the switch Nrf2 is activated, the process cannot proceed without enough DJ-1.  This is why Peter Barnes, from my Dean’s list, suggested that patients with COPD might benefit from more DJ-1.  COPD is a kind of severe asthma which occurs with severe oxidative stress, the oxidative stress stops the standard asthma drugs from working, which is why so many people die from COPD. Oxidative stress is a key feature of most autism.
To make more DJ-1 you can use sodium benzoate (NaB) which is produced gradually in the body if you eat cinnamon. So in theory cinnamon is like sustained release NaB, it is also extremely cheap.
Independently of all this NaB has been trialled in schizophrenia and a further larger trial is in progress.  Autism is not schizophrenia, but the hundreds of genes miss-expressed in autism do overlap with the hundreds of genes miss-expressed in schizophrenia, so I call schizophrenia autism’s big brother. 

GABAA α5 subunit
The scientist readers of this blog may recall that there are two sub-units of the GABAA receptor that I am seeking to modify, to improve cognition.  One is the α3 subunit and the other is the α5 subunit. Low dose clonazepam works for α3.
The α5 subunit is the target of a new drug to improve cognition in people with Down Syndrome (DS).
Very recent research links the same sub-unit to autism, so it is not just me looking at this.

Reduced expression of α5GABAA receptors elicits autism-like alterations in EEG patterns and sleep-wake behavior                                                                                                              

As is often the case, it looks like some people might need to “turn up the volume” from α5GABAA receptors and others might need to turn it down.
I had yet to find a practical way to affect α5GABAA. Now I have realized that I have already stumbled upon such a way to do it.
Pahan, a researcher in Chicago, has shown that he can improve cognition in mice using cinnamon. He noted that in poor learners GABRA5 was elevated, but that after one month of cinnamon GABRA5 was normalized. 

Cognitive loss in autism, schizophrenia and Down Syndrome
Most people might associate MR/ID with autism and indeed Down Syndrome; you likely do not really consider people with schizophrenia to have MR/ID. In reality, cognitive loss is a common feature/problem in schizophrenia and indeed bipolar, just not enough to be called MR/ID.
Those researching schizophrenia seem to focus on NMDA receptors, whereas my blog only goes into the great depths of science when it comes to GABAA . To the schizophrenia researchers NaB is interesting because it is a d-amino acid oxidase inhibitor, which means that it will enhance NMDA function.  So if you are one of those people with too little NDMA activity (NMDAR hypofunction) then sodium benzoate should make you feel better.
The schizophrenia researchers think NaB is helpful because of its effect on NMDA, for me it is GABRA5 that is of great interest. The same should be true for parents of kids with Down Syndrome (DS). We have seen that bumetanide should, and indeed does, help DS.  It looks to me that NaB/Cinnamon should further help them and no need to wait for Roche to commercialize their GABRA5 drug. 

NaB and Cinnamon
I am yet to determine how much NaB is produced by say 3g of cinnamon.
The clinical trials of NaB use 1g per day in adults. People using cinnamon, like Dr Pahan, for cognition or just lowing blood pressure and blood sugar use around 3g.
It is quite difficult to give a teaspoonful of cinnamon to a child, whereas NaB dissolves in water and does not taste so bad. 

NaB and Cinnamon Trials
I did trial cinnamon by putting it in in large gelatin capsules and at the time I did think it had an effect, but I doubt I got close to Dr Pahan’s dosage.
A prudent dose of NaB would seem to be 6mg/Kg twice a day. This is similar to what is now being trialed in schizophrenia.
A small number of people do not tolerate NaB and logically also cinnamon.  They are DAAO inhibitors, just like Risperidone. People who are histamine intolerant need to avoid DAAO inhibitors. If you have allergies it does not mean you are histamine intolerant.
I did try NaB on myself and I did not notice any effect.

I had already obtained some NaB to follow up on my earlier trial of cinnamon.  Having read about the effect of NaB on GABRA5 expression, I am even more curious to see if it helps.
Any positive effect might be due to DJ-1 boosting the effect of Nrf-2, it might be boosting NMDA or it might be reducing GABRA5 expression. In some people all three would be useful.

Press release:- 

Pahan a researcher at Rush University and the Jesse Brown VA Medical Center in Chicago, has found that cinnamon turns poor learners into good ones—among mice, that is. He hopes the same will hold true for people.

His group published their latest findings online June 24, 2016, in the Journal of Neuroimmune Pharmacology.

"The increase in learning in poor-learning mice after cinnamon treatment was significant," says Pahan. "For example, poor-learning mice took about 150 seconds to find the right hole in the Barnes maze test. On the other hand, after one month of cinnamon treatment, poor-learning mice were finding the right hole within 60 seconds."

Pahan's research shows that the effect appears to be due mainly to sodium benzoate—a chemical produced as cinnamon is broken down in the body.

In their study, Pahan's group first tested mice in mazes to separate the good and poor learners. Good learners made fewer wrong turns and took less time to find food. 

In analyzing baseline disparities between the good and poor learners, Pahan's team found differences in two brain proteins. The gap was all but erased when cinnamon was given. 

"Little is known about the changes that occur in the brains of poor learners," says Pahan. "We saw increases in GABRA5 and a decrease in CREB in the hippocampus of poor learners. Interestingly, these particular changes were reversed by one month of cinnamon treatment." 

The researchers also examined brain cells taken from the mice. They found that sodium benzoate enhanced the structural integrity of the cells—namely in the dendrites, the tree-like extensions of neurons that enable them to communicate with other brain cells

As for himself, Pahan isn't waiting for clinical trials. He takes about a teaspoonful—about 3.5 grams—of cinnamon powder mixed with honey as a supplement every night.  
Should the research on cinnamon continue to move forward, he envisions a similar remedy being adopted by struggling students worldwide. 

The paper itself:- 

This study underlines the importance of cinnamon, a commonly used natural spice and flavoring material, and its metabolite sodium benzoate (NaB) in converting poor learning mice to good learning ones. NaB, but not sodium formate, was found to upregulate plasticity-related molecules, stimulate NMDA- and AMPA-sensitive calcium influx and increase of spine density in cultured hippocampal neurons. NaB induced the activation of CREB in hippocampal neurons via protein kinase A (PKA), which was responsible for the upregulation of plasticity-related molecules. Finally, spatial memory consolidation-induced activation of CREB and expression of different plasticity-related molecules were less in the hippocampus of poor learning mice as compared to good learning ones. However, oral treatment of cinnamon and NaB increased spatial memory consolidation-induced activation of CREB and expression of plasticity-related molecules in the hippocampus of poor-learning mice and converted poor learners into good learners. These results describe a novel property of cinnamon in switching poor learners to good learners via stimulating hippocampal plasticity. 

We have seen that cinnamon and NaB modify T cells and protect mice from experimental allergic encephalomyelitis, an animal model of multiple sclerosis. Cinnamon and NaB also upregulate neuroprotective molecules (Parkin and DJ-1) and protect dopaminergic neurons in MPTP mouse model of Parkinson’s disease.  Recently, we have seen that cinnamon and NaB attenuate the activation of p21ras, reduce the formation of reactive oxygen species and protect memory and learning in 5XFAD model of AD. Here we delineate that NaB is also capable of improving plasticity in cultured hippocampal neurons. Our conclusion is based on the following: First, NaB upregulated the expression of a number of plasticity-associated molecules (NR2A, GluR1, Arc, and PSD95) in hippocampal neurons. Second, Gabra5 is known to support long-term depression. It is interesting to see that NaB did not stimulate the expression of Gabra5 in hippocampal neurons. Third, NaB increased the number, size and maturation of dendritic spines in cultured hippocampal neurons, suggesting a beneficial role of NaB in regulating the synaptic efficacy of neurons. Fourth, we observed that NaB did not alter the calcium dependent excitability of hippocampal neurons, but rather stimulated inbound calcium currents in these neurons through ionotropic glutamate receptor. Together, these results clearly demonstrate that NaB is capable of increasing neuronal plasticity.

These results suggest that NaB and cinnamon should not cause health problems and that these compounds may have prospects in boosting plasticity in poor learners and in dementia patients. In summary, we have demonstrated that cinnamon metabolite NaB upregulates plasticity-associated molecules and calcium influx in cultured hippocampal neurons via activation of CREB. While spatial memory consolidation-induced activation of CREB and expression of plasticity-related molecules were less in the hippocampus of poor learning mice as compared to good learning ones, oral administration of cinnamon and NaB increased memory consolidation-induced activation of CREB and expression of plasticity-related molecules in vivo in the hippocampus of poor learning mice and improved their memory and learning almost to the level that observed in untreated good learning ones. These results highlight a novel plasticity-boosting property of cinnamon and its metabolite NaB and suggest that this widely-used spice and/or NaB may be explored for stimulating synaptic plasticity and performance in poor learners.

The schizophrenia trials:-

Plenty of people with schizophrenia now self-treat with NaB; just look on google.

There is now is a small trial in autism:-

A Pilot Trial of Sodium Benzoate, a D-Amino Acid Oxidase Inhibitor, Added on Augmentative and Alternative Communication Intervention for Non-Communicative Children with Autism Spectrum Disorders

Results: We noted improvement of communication in half of the children on benzoate. An activation effect was reported by caregivers in three of the six children, and was corroborated by clinician’s observation. Conclusion: Though the data are too preliminary to draw any definite conclusions about efficacy, they do suggest this therapy to be safe, and worthy of a double-blind placebo-controlled study with more children participated for clarification of its efficacy.