Early Postnatal Valproic Acid Exposure Increase the Protein Level of Astrocyte Markers in Frontal Cortex of Rat

OBJECTIVE: In our previous study, it has been reported that valproic acid (VPA) effects gliogenesis and increases the number of glial precursor cells during the early postnatal period. However there is no specific report that whether this process is going on up to the age of mature brain development and the consequence effect of this ongoing gliogenesis process. METHODS: As an ongoing study, using Immunoblotting analysis, we checked the level of glial protein and glial-derived factor markers in the frontal cortex of a rat brain at postnatal day (PND) 21. RESULTS: The finding of the study suggests that, in the VPA group (p < 0.05), early exposure elicited significantly to increase the expression level of glial protein cells at PND 21 in the frontal cortex of rat brain. CONCLUSION: Therefore we suggest that, alter gliogenesis and abnormal number of glial cells modulate the neurobiological dysfunction and induces the risk of neurodevelopmental disorders.

Empathy Study in Rodent Model of Autism Spectrum Disorders

There is a highly cognitive and social context to empathy behavior in human. In various social contexts, rodents also display remarkable affective sensitivity and exhibit primitive forms of empathy similar to human. Therefore, we aimed to elaborate the concept of empathy about various components of empathetic behavior in rodents with the similar contexts of a human. In this review, we highlighted the behavioral paradigm that already examined different aspects of rodent empathetic behavior in response to conspecific distress. Additionally, we summarized homologous brain parts of human and rodents to express the empathetic behavior. Integrating the findings with corresponding experiments in the human will provide a novel insight into therapeutic intervention or expanded experimental approaches for neuropsychiatric disorders like autism spectrum disorders associated with empathetic behavior.

Valproic Acid Exposure during Early Postnatal Gliogenesis Leads to Autistic-like Behaviors in Rats

OBJECTIVE: We reported that postnatal exposure of rats to valproic acid (VPA) stimulated proliferation of glial precursors during cortical gliogenesis. However, there are no reports whether enhanced postnatal gliogenesis affects behaviors related to neuropsychiatric disorders. METHODS: After VPA treatment during the postnatal day (PND) 2 to PND 4, four behavioral test, such as open field locomotor test, elevated plus maze test, three-chamber social interaction test, and passive avoidance test, were performed at PND 21 or 22. RESULTS: VPA treated rats showed significant hyperactive behavior in the open field locomotor test (p<0.05). Moreover, the velocity of movement in the VPA group was increased by 69.5% (p<0.01). In the elevated plus maze test, VPA exposed rats expressed significantly lower percentage of time spent on and of entries into open arms more than the control group (p<0.05). Also, both sociability and social preference indices with strangers in the three-chamber social interaction test were significantly lower in the VPA exposed rats (p<0.05). CONCLUSION: Our results suggest that altered glial cell development is another locus at which pathogenetic factors can operate to contribute to the neurodevelopmental disorder.