Changes with aging and ischemia in nicotinic acetylcholine receptor subunit α7 mRNA expression in postmortem human frontal cortex and putamen

Age-related changes in nicotinic acetylcholine receptor (nAChR) subunit alpha7 messenger RNA (mRNA) expression in postmortem human frontal cortex and putamen of controls and status lacunaris patients were investigated using nonradioactive reverse transcription(RT)-PCR. In the frontal cortex of control brains, alpha7 subunit mRNA significantly decreased with age (P0.05). In the putamen, alpha7 subunit mRNA expression was significantly lower than that in the frontal cortex (P0.0001), and showed no significant correlation with age. However, in cases with status lacunaris in the putamen, alpha7 subunit mRNA expression was significantly higher compared with controls (P0.001). The reduction in alpha7 nAChR in the frontal cortex with age may decrease functional cholinergic synapses and cortical activity, and play a role in the cognitive impairments associated with normal aging. The functional significance of the upregulation of alpha7 nAChR mRNA in ischemic conditions remains to be determined.