Long-term Effects of Maternal Deprivation on the Volume, Number and Size of Neurons in the Amygdala and Nucleus Accumbens of Rats

Maternal deprivation (MD) in rodents is an important neurodevelopmental model for studying a variety of behavioral changes which closely resemble the symptoms of schizophrenia in humans. To determine whether early-life stress leads to changes in the limbic system structures: the amygdala and the nucleus accumbens, 9-day-old Wistar rats were exposed to 24 hour MD. On P60 the rats were sacrificed for morphometric analysis and their brains were compared to the control group. Results show that MD affected important limbic system structures: the amygdala and the nucleus accumbens, whose volume was decreased (17% of the control value for the amygdala and 9% of the control value for the nucleus accumbens ), as well as the number of neurons (41% of the control value for the amygdala and 43% of the control value for the nucleus accumbens ) and the size of their cells soma (12% of the control value for the amygdala and 33% of the control value for the nucleus accumbens ). This study indicates that early stress in life leads to changes in the morphology of the limbic areas of the brain, most probably due to the loss of neurons during postnatal development, and it further contributes to our understanding of the effects of maternal deprivation on brain development.