Neurobiology of the aging brain: morphological alterations at synaptic regions.
Computer-assisted morphometric studies have been carried out on nerve cell terminal regions in rats of different ages. The numerical density (Nv), the average area (S) and the surface density (Sv) of ethanol phosphotungstic acid stained (E-PTA) synaptic junctions were evaluated in cerebellar glomeruli and dentate gyrus supragranular layers. The volume density (Vv), the average volume (V) and the numerical density (Nvm) of synaptic mitochondria were measured in the cerebellar glomeruli of young (3 months), adult (11 months) and old (28 months) animals. We found that during aging Nv and Sv undergo a significant decrease, whereas S is significantly increased. The mitochondrial Vv is unchanged in all the age groups analysed, whereas in old rats V is increased and Nvm decreased, respectively. We interpret our results as supporting that the old CNS retains part of its remodelling activity and is capable of adaptive morphological response at synaptic terminal regions.
Bertoni-Freddari
C
C
Centre for Surgical Research (Neurobiology Unit), INRCA Research Department, 60121 Ancona, Italy.
Fattoretti
P
P
Casoli
T
T
Pieroni
M
M
Meier-Ruge
W
W
Ulrich
J
J