Early Maternal Separation as a Precursor of Neurodevelopmental and Neurobehavioural Disorders

Abstract

The mother-infant bond plays a pivotal role in early neurodevelopment, and disruptions to this relationship can lead to significant behavioral and neurochemical alterations. This study explores the impact of maternal separation on cognitive and exploratory behaviors, redox status, and neuroanatomy in the prefrontal cortex of juvenile rats. Female rats were bred and assigned to either a control or maternal separation (MS) group, with maternal separation pups experiencing a 24-hour separation from their mothers on postnatal day nine. Behavioral assessments using the open field test revealed marked reductions in total line crossings and rearing frequency in the MS group, indicating deficits in cognitive and exploratory behavior. Biochemical assays showed significant increase in oxidative stress markers, including malondialdehyde, and reduction in antioxidant enzyme activity, namely superoxide dismutase and catalase, in the prefrontal cortex of MS rats. Histological observation further revealed signs of cellular degeneration, including poorly stained nuclei and increased chromatolytic cells, in MS rats compared to control. Additionally, increased astrocyte reactivity, as evidenced by hypertrophied astrocytes and higher astrocyte counts, was observed in the prefrontal cortex of MS rats. These findings suggest maternal separation induces oxidative stress and cellular degeneration in the prefrontal cortex, potentially underlying behavioral deficits observed in MS rats. This model provides insights into the neurobiological mechanisms by which early-life adversity impacts neurodevelopment, with potential implications for understanding the development of neuropsychiatric disorders in humans exposed to early-life stress.