RABIES VIRUS SELECTIVELY ALTERS 5-HT(1) RECEPTOR SUBTYPES IN RAT-BRAIN

Rabies virus infection in man induces a series of clinical symptoms, s ome suggesting involvement of the central serotonergic system. The res ults of the present study show that, 5 days after rabies virus infecti on in rat, the total reversible high-affinity binding of [H-3]5-HT in the hippocampus is not affected, suggesting that 5-HT1A binding is not altered. 5-HT1B sites identified by [I-125]cyanopindolol binding are not affected in the cortex 3 and 5 days after the infection. According ly, the cellular inhibitory effect of trifluoromethylphenylpiperazine (TFMPP) on the [H-3]acetylcholine-evoked release, presumably related t o 5-HT1B receptor activity, is not modified 3 days after infection. In contrast, [H-3]5-HT binding determined in the presence of drugs maski ng 5-HT1A, 5-HT1B and 5-HT1C receptors, is markedly (50%) reduced 3 da ys after the viral infection. These results suggest that 5-HT1D-like r eceptor subtypes may be affected specifically and at an early stage af ter rabies viral infection.