In utero exposure to anti-Caspr2 antibody disrupts parvalbumin interneuron function in the hippocampus.

This animal study found that when pregnant mothers had specific antibodies (anti-Caspr2), their male offspring had fewer important brain cells that help control brain activity balance. These brain changes were linked to unusual brain wave patterns during social interactions, which may help explain some autism-related behaviors. The research suggests that certain maternal immune factors during pregnancy could affect brain development in ways that contribute to autism.

This study investigated how maternal antibodies against Caspr2 protein affect brain development in offspring, specifically examining their impact on parvalbumin-expressing interneurons in the hippocampus. Using an animal model, researchers found that in utero exposure to anti-Caspr2 antibodies led to reduced numbers of these critical inhibitory neurons and fewer inhibitory synapses in the CA1 hippocampal region of male offspring. Functional recordings revealed increased gamma brain wave activity and altered neuronal firing patterns during social interactions, suggesting disrupted excitatory-inhibitory balance. These findings provide mechanistic insights into how maternal autoimmune factors may contribute to autism spectrum disorder development through specific effects on inhibitory brain circuits that regulate social behavior and neural network activity.

Suggests maternal anti-Caspr2 antibodies may contribute to autism risk through disruption of inhibitory brain circuits. Could inform future screening approaches for pregnant women and highlight importance of maternal autoimmune status. May guide development of targeted interventions focusing on excitatory-inhibitory balance in autism treatment approaches.

Sample size not reported, limiting assessment of statistical power. Study appears to focus only on male offspring, restricting generalizability to females. Animal model findings may not directly translate to human autism development. Specific behavioral assessments beyond neuronal recordings during social interactions are not described in the abstract.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by deficits in communication and social interaction and may stem from an imbalance between excitatory and inhibitory (E/I) signaling in neural circuits. Parvalbumin-expressing (PV+) interneurons are crucial for maintaining E/I balance and regulating network oscillations. Alterations in the number of PV+ interneurons or reductions in PV expression have been observed in both the postmortem brains of individuals with ASD and in animal models, including those induced by in utero exposure to maternal brain-reactive antibodies. In this study, we investigate the impact of in utero exposure to maternal anti-Caspr2 IgG on PV+ interneuron development and function in the hippocampus.

Our results demonstrate a selective reduction in PV+ interneurons and perisomatic inhibitory synapses in the hippocampal CA1 region of juvenile and adult male offspring exposed in utero to anti-Caspr2 antibodies compared to controls. Additionally, local field potential (LFP) recordings from these mice show increased gamma power and altered neuronal firing patterns during social interactions, indicating functional impairments in inhibitory circuitry. These findings highlight the consequences of exposure to maternal anti-Caspr2 antibodies on PV+ interneuron development and function, providing insights into the neurobiological mechanisms underlying ASD associated behavioral phenotypes.