AGE-RELATED ASSESSMENT OF CENTRAL 5-HT1A RECEPTORS FOLLOWING IRREVERSIBLE INACTIVATION BY N-ETHOXYCARBONYL-2-ETHOXY-1,2-DIHYDROQUINOLINE (EEDQ)

Age-dependent differences in the ability of N-ethoxycarbonyl-2-ethoxy- 1,2-dihydroquinoline (EEDQ) to irreversibly inactivate 5-HT1A recepto rs were investigated in female Fischer 344 rats (ages 3 and 22 months) . In the hippocampus, frontal cortex and amygdala, EEDQ reduced 5-HT1A receptor density (33-70%) and drug affinity (2.3-6.2 fold) as determi ned by Scatchard analyses using [H-3]8-hydroxy-2-(di-N-propylamino)tet ral In the frontal cortex, the reduction in B-max values was significa ntly greater in 3 months vs. 22 months groups. These region-specific a nd age-dependent alterations in 5-HT1A receptors may be of pathophysio logical significance in age-related cognitive decline and Alzheimer's disease.