Structural synaptic remodeling in the perirhinal cortex of adult and old rats following object-recognition visual training.
The ultrastructural features of layer II synapses in the perirhinal cortex of adult (4- to 6-month-old) and old (25- to 27-month-old) rats exposed to a six-session object recognition visual training were investigated by morphometric methods. The comparative analysis showed a higher synaptic numeric density, a lower synaptic average area, and a lower percentage of megasynapses (S > 0.5 microm2) in old trained rats versus controls, and a higher percentage of small (S < 0.15 microm2) junctions in adult trained rats versus controls. The more marked synaptic remodeling underlying memory consolidation in the perirhinal cortex of old rats might reflect a pre-existing lower dynamic status.
Platano
D
D
Department of Human and General Physiology, University of Bologna, Bologna, Italy.
Bertoni-Freddari
C
C
Fattoretti
P
P
Giorgetti
B
B
Grossi
Y
Y
Balietti
M
M
Casoli
T
T
Di Stefano
G
G
Aicardi
G
G
D000375:Aging / Q000473:pathology* / Q000523:psychology*; D000818:Animals; D018728:Entorhinal Cortex / Q000166:cytology*; D008297:Male; D008568:Memory; D051381:Rats; D017208:Rats, Wistar; D021641:Recognition, Psychology; D013569:Synapses / Q000648:ultrastructure*; D013702:Temporal Lobe / Q000166:cytology