Maintenance of inhibitory interneurons and boutons in sensorimotor cortex between middle and old age in Fischer 344 X Brown Norway rats.

Ultrastructurally identified inhibitory synapses in layer II of rat sensorimotor cortex decline between middle and old age [Poe, B.H., Linville, C.

Stereological quantification of GAD-67-immunoreactive neurons and boutons in the hippocampus of middle-aged and old Fischer 344 x Brown Norway rats.

The aging process in rodents is associated with learning and memory impairments that are correlated with changes in multiple neurotransmitter systems in the hippocampus. For example, the gamma-aminobutyric acid (GABA)ergic system is compromised in old compared with young rats (Shetty and Turner [1998] J. Comp.

Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus.

Aging-related impairments of learning and memory can be ameliorated by 28 days of intracerebroventricular (icv) infusion of insulin-like growth factor-1 (IGF-1) in old rats. The present study investigated whether there is an aging-related synaptic decline in the stratum radiatum of hippocampal CA1 and whether IGF-1 can ameliorate that decline. Five young (4 months), five middle-aged (18 months) and five old (29 months) Fischer 344xBrown Norway rats received saline infusion; five old (29 months) rats received IGF-1 infusion for 28 days preceding sacrifice.

Caloric restricted male rats demonstrate fewer synapses in layer 2 of sensorimotor cortex.

Previous studies have demonstrated an age-related decline in the density of presumptive inhibitory synapses in layer 2 of rat sensorimotor cortex [J. Comp. Neurol.