DOPAMINERGIC NEUROTRANSMISSION IN CHRONIC HERPES-SIMPLEX VIRUS BRAIN INFECTION IN RABBITS

In this study we have examined brain concentrations of monoamine neuro transmitters and striatal and mesencephalic D-2 receptors in a chronic model of herpes simplex virus (HSV) encephalitis. The HSV-inoculated rabbits were killed two months after inoculation. Dopamine (DA), norad renaline, serotonin and their metabolites were determined in the subst antia nigra, caudate nucleus, putamen, nucleus accumbens, and olfactor y tubercles using HPLC with electrochemical detection. The B(max) and K(d) values of D-2 receptors were studied in the striatum and in the m esencephalon using H-3-spiroperidol as ligand. The animals showed rota tional behaviour, consisting of posture tilting to the inoculated side and circling in the same direction during the first week, then slowly subsiding. Compared with controls, the concentration of homovanillic acid (HVA) was reduced in the ascending DA system on both sides. Neith er in the number nor affinity of D-2 receptors were there any differen ces between the HSV-inoculated and control rabbits. The decreased HVA concentrations suggest that dopaminergic hypofunction can develop as a consequence of previously experienced acute HSV brain infection.