MONOAMINE NEUROTRANSMITTERS AND AMINO-ACIDS IN THE CEREBRUM AND STRIATUM OF IMMATURE RATS WITH KAOLIN-INDUCED HYDROCEPHALUS

Hydrocephalus is characterized by enlargement of the cerebral ventricl es. The behavioral disturbances are, in some cases, rapidly reversible by surgical treatment suggesting that there may be a functional impai rment of neurons. Hydrocephalus was induced in 5-week old rats by kaol in injection into the cisterna magna. Parietal cerebrum and striatum c ontent of monoamine neurotransmitters and amino acids were assayed by high performance liquid chromatography (HPLC), 1, 2, or 4 weeks after induction of hydrocephalus. The ventricles exhibited progressive enlar gement which was partially reversed by surgical treatment. Cerebral wa ter content was increased at all stages. Increased levels of cerebral aspartate and glutamate suggest that there is the potential for excita tory neurotoxicity. The increase in cerebral taurine correlated negati vely with the increase in water content. Cerebral concentrations of no repinephrine and serotonin, and its metabolite 5-HIAA, were increased at 1 and 2 weeks suggesting an increase in their turnover during the e arly stages of ventricular dilatation. Dopamine and its metabolite DOP AC were transiently diminished in the striatum at 1 and 2 weeks, respe ctively, suggesting that axonal projections from the brainstem may be impaired. We conclude that the effect of hydrocephalus on amino acids and monoamines varies regionally. Due to increased water content, ther e may be dilution effects in whole tissue, therefore, it is important to make determinations on the basis of protein content. (C) 1998 Elsev ier Science B.V. All rights reserved.