Cerebral serotonin in viral encephalitis
In order to evaluate central serotonergic function during viral encephalitis biochemical, behavioural and immunohistofluorescence studies were carried out. Mice were inoculated with the moderate virulent strain of Venezuelan equine encephalomyelitis virus, Pixuna. Signs of encephalitis were observed in 50–60% of infected animals. Levels of serotonin and 5-hydroxyindolacetic acid, and the ratio of the indolamine and its metabolite in raphe and cortex did not change with respect to sham-inoculated mice. A differential decrease in turnover rate by pharmacological methods, such as pargyline, p-chlorophenylalanine and probenecid administration, was observed in raphe and cortex. The ratio serotonin turnover rate/steady state concentration of serotonin was only decreased in the raphe of sick animals. The response to 5-methoxy-N, N-dimethyltrypt-amine was greater in infected animals. The duration of immobility in the swim test was shorter in the infected group. A greater number of viral antigen particles was localized in raphe and periraphe areas than in cortex, brain stem or striatum. The results suggest a serotonin presynaptic deficit, a postsynaptic hyperreactivity of serotonin system, and a region-selective distribution of the virus.
KeywordsViral Encephalitis Venezuelan Equine Encephalomyelitis Virus Sick Animal BioI Psychiatry Monoamine Metabolism
Unable to display preview. Download preview PDF.
- Corne SJ, Pickering RE, Warner BT (1963) A method of assessing the effects of drugs on the central actions of 5-hydroxytryptamine. Br J Pharmacol 20: 106–210.Google Scholar
- Crow TJ (1987) Psychosis as a continuum and the virogene concept. Br Med Bull 43: 755–767.Google Scholar
- Fields BN, Weiner HL (1982) Mechanism of viral injury to the nervous system. In: Sears TA (ed) Neuronal-glial cell inter-relationships, pp 217-228.Google Scholar
- Gibson CJ, Diekel SM, Young SN, Binik TM (1982) Behavioural and biochemical effects of tryptophan, tyrosine and phenylalanine and central serotonin neurons. Pol J Pharmacol Pharm 25: 29–39.Google Scholar
- Johnson RT (1982) Viral infections of the nervous system. Raven Press, New York.Google Scholar
- Kristensson K (1982) In: Weiss DG, Gorio A (eds) Axoplasmic transport in physiology and pathology. Springer, Berlin Heidelberg New York, pp 153–159.Google Scholar
- Rhodes RH, Novak R, Beattie JF, West HM, Whetsell WO (1984) Immunoperoxidase demonstration of herpes simplex virus Type-I in the brain of a psychotic patient without history of encephalitis. Clin Neurol 3: 59–67.Google Scholar
- Sokal R, Rohlf F (1979) Biometria. Blume Ediciones, Madrid.Google Scholar
- Tsiang H, Gourmelon P, Briet D, Court L (1988) Sleep stace and EEG alterations in rabies. Neurochem Int 13: 65.Google Scholar
- Tyler KL (1986) Localized infection of the central nervous system. Curr Ther Infect Dis 1: 216–225.Google Scholar
- von Economo C (1931) Encephalitis lethargic: its sequelae and treatment. Oxford University Press, London.Google Scholar
- Ziegler RJ, Trachte G, Stauffer E (1988) Persistent virus effects on neuronal electrophy-siology and prostaglandin metabolism. Neurochem Int 13: 65.Google Scholar