Study of neuronal and glial density prefrontal cortex of rats subjected to maternal separation and environmental enrichment

• Grant number: 14/16077-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2014
• End date: May 04, 2016
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Jorge Eduardo Moreira
• Grantee: Ana Beatriz Souza Nakayama
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Stressful events in childhood promote brain and behavioral changes that persist throughout life. Maternal separation is one of the most used animal models to study the effects caused by neonatal stress and several disorders such as depression and schizophrenia. The volume of the prefrontal cortex and hippocampus are reduced in many psychiatric disorders. Reduction in the number of granule neurons of the dentate gyrus of the hippocampus of animals subjected to maternal separation was found in several studies, but there is no data on the number of neurons in the prefrontal cortex of these animals. Studies in our laboratory have shown a reduction of the immunopositive area to doublecortin, neuroblasts marker protein, in the hippocampus of animals subjected to maternal separation. A reduction of the volume of the prefrontal cortex and the hippocampus observed in schizophrenic or chronically depressed individuals may be partly due to greater apoptosis. As the prefrontal cortex is not considered a neurogenic region in adults, a possible decrease in the volume of prefrontal cortex in animals subjected to maternal separation could be caused by the reduction in the number of neurons and/or glial cells in this region, possibly due to increased apoptosis. Moreover, the environmental enrichment promotes changes which are opposite to those caused by this neonatal stress model, what motivates us to study whether the changes caused by neonatal stress can be reversed or attenuated by environmental enrichment. (AU)