FINE ARCHITECTURE OF THE HIPPOCAMPUS IN ADOLESCENT, ADULT AND AGED RATS. ELECTRON MICROSCOPIC STUDY

The study included adolescents (P30-36), adult (P125-130) and aged (P330-340) male Wistar rats - 4 animals in each age group. The rats were housed individually, in wire-top polypropylene cages (30-cm width x 30 cm length x 25 cm height) and maintained on a 12-h light/dark cycle. Standard food pellets and tap water were ad libitum. The animal maintenance and electron microscopic procedures were conducted in accordance with European Union Directive on the protection of animals used for scientific research. The Ultrastructure of adult and adolescent rats are almost same. However, remarkable changes are expressed between adult and senescent rats. Precisely, in the last one there are following ultrastructural modifications - lipofuscin concentrations, small destructive cytoplasmic organelles, changes in presynaptic vesicular and mitochondrial quantity. Rare apoptotic signs in neurons. Analysis of all this means that aging in rat's hippocampus causes selective changes, also it underlines changes in neurotransmission and neuronal developmental pathways.