The effects of antipsychotics on the density of cannabinoid receptors in selected brain regions of male and female adolescent juvenile rats

Role of the endocannabinoid system in neurological disorders

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that begins in infancy. Although the etiology and pathogenesis are poorly understood, many studies have shown that ASD is closely related to structural and functional defects in the nervous system, especially synaptic transmission. The endocannabinoid (eCB) system is an important regulatory system of the central nervous system that regulates neurotransmission and synaptic plasticity and plays an important role in emotional and social responses and cognitive function. The relationship between eCB system and ASD has attracted increasing attention from scholars. In this review, we discuss the complex lipid signaling network of the eCB system, intracellular transport pathways, abnormal expression and association with various neurological diseases, and direct and indirect evidence for the link between eCB and ASD. Collectively, the findings to date indicate that the eCB system plays a key role in the pathophysiology of ASD and can provide new insights into potential interventions and rehabilitation strategies for ASD.

Early antipsychotic exposure affects NMDA and GABAA receptor binding in the brains of juvenile rats

Antipsychotics were developed to treat schizophrenia in adults; however they have been increasingly prescribed in children and adolescents. The NMDA and GABA_A receptors are involved in neurodevelopment and the pathophysiology of various mental disorders in children and adolescents. Male and female juvenile rats were treated orally with risperidone (0.3 mg/kg, 3 times/day), aripiprazole (1 mg/kg), olanzapine (1 mg/kg) or vehicle (control), starting from postnatal day (PD) 23 (±1 day) for 3 weeks (corresponding to the childhood-adolescent period in humans). Quantitative autoradiography was used to detect the binding density of [³H]MK-801 (an NMDA receptor antagonist) and [³H]muscimol (a selective GABA_A receptor agonist). Aripiprazole elevated the [³H]MK801 binding levels in the NAcC of male rats, and the NAcS and CPu of female rats. Risperidone increased [³H]MK801 levels in the CPu of female rats, and the NAcS of male rats. Aripiprazole upregulated [³H]muscimol binding levels in the CPu and NAcC of male rats, while it elevated the [³H]muscimol levels in the PFC of female rats, compared to controls. These results suggest that early treatment with these antipsychotics modulates NMDA and GABA_A neurotransmission in juveniles, which may play a role in their clinical efficacy in the control of mental disorders in children and adolescents.