POSTNATAL-DEVELOPMENT OF ARGYROPHILIC NUCLEOLAR ORGANIZER REGIONS IN THE MAMMILLARY BODY OF UNDERNOURISHED RATS

The effects of undernutrition during pregnancy and/or lactation period s on cortical structures have already been reported. However, its effe ct on non-cortical areas like the hypothalamic, that participates in t he regulation of the autonomic nervous system or food intake, has not been extensively investigated. We studied the postnatal development of the medial mammillary nucleus (hypothalamus) in the rat offspring tha t had a dietary restriction in utero and during lactation. The argyrop hilic nucleolar regions (Ag-NORs), that represent the transcriptional activity of the cell, were quantified in their neurons. No statistical ly significant differences were found in the results between the contr ol and undernourished groups in the ages studied (7, 14, 21 and 30 day s). However, a delay in the neuronal activity of the latter group was observed. A critical period in the development of this nucleus, at abo ut 21 days of age, was also seen in both groups. After this age, the a ctivity levels remained steady.