Postweaning positive modulation of α5GABAA receptors improves autism-like features in prenatal valproate rat model in a sex-specific manner.
A rat study shows that boosting α5-GABAA receptors can ease autism-like social and repetitive traits, but boys and girls need different doses.
01Research in Context
What this study did
Scientists gave a drug called MP-III-022 to baby rats. The rats were exposed to valproic acid before birth. This exposure creates autism-like traits.
The drug boosts a special GABA receptor called α5. The team watched how the rats played and repeated actions. They tracked males and females separately.
What they found
The drug eased social problems and repetitive actions. Boys and girls responded at different doses. Brain GABA markers also shifted.
Overall, the treatment helped the core autism-like signs in this rat model.
How this fits with other research
Souza et al. (2024) tested a similar α5-GABAA drug in the same rat model. They saw social gains only in males. The 2022 study adds that repetition also drops, and girls need a different dose.
Brondino et al. (2016) reviewed human GABA pills for autism. They found no clear win. The new rat data do not clash; human trials simply have not reached this receptor subtype yet.
Anshu et al. (2017) showed that VPA rats learn poorly on attention tasks. The 2022 paper now shows that, with the right drug, these rats can still show normal social and play behaviors.
Why it matters
The work points to a fresh drug target: α5-GABAA receptors. It also shouts "watch sex" when dosing. For you, the lesson is to track boy-girl response curves in any new intervention. Keep an eye on this receptor; human safety trials may start soon.
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Add a sex-based data column when you track any new intervention, ready to spot dose or response differences.
02At a glance
03Original abstract
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 GABAA 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.
Autism research : official journal of the International Society for Autism Research, 2022 · doi:10.1002/aur.2699