Age-related synaptic changes in the CA1 stratum radiatum and spatial learning impairment in rats.
1. Age-related impairments in hippocampus-dependent spatial learning and memory are not associated with a loss of neurons, but may be related to synaptic changes. In the present study, we analysed the behavioural performance of adult, middle-aged and old Wistar rats using the Morris water maze, as well as the structure of synapses and the expression of autophosphorylated Ca(2+)/calmodulin-dependent protein kinase II at threonine 286 (pThr286-alphaCaMKII), a key post-synaptic protein in the CA1 stratum radiatum, in the same rats. 2. Old Wistar rats showed significant cognitive deficits. Synaptic density, the area of post-synaptic densities and the total number of synapses in the CA1 stratum radiatum of old rats were significantly decreased compared with adult rats. The decrease in autophosphorylated pThr286-alphaCaMKII was age dependent. 3. These findings reveal that age-related impairments in learning and memory are associated with synaptic atrophy. The decreased expression of pThr286-CaMKII may result in reduced synaptic function with ageing.
Long
Li-Hong
LH
Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Liu
Rui-Li
RL
Wang
Fang
F
Liu
Jue
J
Hu
Zhuang-Li
ZL
Xie
Na
N
Jin
You
Y
Fu
Hui
H
Chen
Jian-Guo
JG
D000375:Aging / Q000473:pathology* / Q000523:psychology; D000818:Animals; D056547:CA1 Region, Hippocampal / Q000473:pathology* / Q000502:physiology; D007858:Learning / Q000502:physiology; D007859:Learning Disabilities / Q000473:pathology* / Q000523:psychology; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013037:Spatial Behavior / Q000502:physiology; D013569:Synapses / Q000473:pathology* / Q000648:ultrastructure