title: Memory and postsynaptic cholinergic receptors in aging mice.
abstract: Significant retention deficits were observed on passive avoidance tasks (step-down and step-through) in 15-, 20-, and 25-month-old male C57BL/6 mice compared with 4- and 8-month-old mice. In contrast, cholinergic muscarinic receptor binding ( [3H]quinuclidinyl benzilate) in cerebral cortex, striatum, hippocampus, and cerebellum in these same animals revealed no difference in this 4- to 25-month age range. In a separate comparison of 4- and 29-month-old female mice, [3H]QNB binding was significantly decreased in the older group in cerebral cortex, hippocampus, and striatum. Environmental enrichment, compared with an impoverished environment, significantly improved retention in mice on 24-hr step-down performance but affected QNB binding only minimally (6-7% decrease of QNB binding in cerebral cortex and hippocampus). Benzodiazepine ( [3H]flunitrazepam) receptor binding was significantly (12-15%) decreased in 29-month-old mice compared with 4-month-old mice in the cerebral cortex, hippocampus, cerebellum, and brain stem.
mesh_terms: D000375:Aging; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D004193:Discrimination Learning / Q000502:physiology; D005239:Fear / Q000502:physiology; D005445:Flunitrazepam / Q000378:metabolism; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000502:physiology*; D011955:Receptors, Drug / Q000502:physiology; D011963:Receptors, GABA-A; D012153:Retention, Psychology / Q000502:physiology; D012931:Social Environment; D013569:Synapses / Q000502:physiology*
chemical_list: D011950:Receptors, Cholinergic; D011955:Receptors, Drug; D011963:Receptors, GABA-A; D005445:Flunitrazepam; D011813:Quinuclidinyl Benzilate