Long-term effects of adolescent risperidone treatment on the mouse cortex.

Since the introduction of second-generation antipsychotics, antipsychotics have been increasingly prescribed for children and adolescents, raising concerns about their long-term impact on neurodevelopment. Antipsychotics block dopaminergic and serotonergic receptors, potentially disrupting the maturation of neurocognitive processes, which is a public health concern. Previous studies have reported that adolescent antipsychotic treatment can cause persistent neurocognitive dysfunction in rodents, yet the neurobiological underpinnings remain unknown. To address this, we administered risperidone, a commonly used antipsychotic, to C57BL/6 mice during adolescence (3 to 6 weeks of age) and examined behavioral and neurobiological outcomes nine weeks post-treatment. Risperidone-treated mice exhibited subtle deficits in behavioral correlates of anxiety-like behavior. In vivo, two-photon calcium imaging of cortical neurons revealed a remarkable increase in the amplitude of calcium events with subtle sex-specific changes in the frequency, consistent with increased neuronal excitability. Single-nucleus RNA-sequencing (snRNA-seq) analyses showed widespread reductions in transcripts for voltage-sensitive and inwardly rectifying potassium channels in both pyramidal neurons and interneurons. Additionally, both cell types exhibited reduced Grin2a and Grin2b, as well as scaffolding proteins, indicative of weakened synaptic connectivity between excitatory and inhibitory neurons. Interestingly, we observed sex-dependent differences in the directionality of correlation between certain gene co-expression modules and risperidone treatment. Our results suggest that adolescent risperidone treatment induces lasting transcriptomic and functional changes associated with altered excitatory-inhibitory neuronal interactions that may underline cognitive and behavioral dysregulations.