Intracerebral Monoamine Concentration after Ventriculoperitoneal Shunting in the Congenital Hydrocephalus Rat

Abstract

This study investigated the relationship between neurotransmitters and improvement of symptoms after ventriculoperitoneal shunting in congenital hydrocephalus (LEW-HYR) rats. Twenty-four patent hydrocephalus rats, aged 12-14 days, were randomly assigned to the following four groups: ventriculoperitoneal shunt group, obstructed shunt group, burr hole group, and no treatment group. In addition, six normal rats served as control group. Head to body length ratio was measured before and 7 days after the procedures. Coordination movement was evaluated on the 7th postoperative day. High performance liquid chromatography (HPLC) was used to measure the concentrations of dopamine (DA), norepinephrine (NE), serotonin, homovanillic acid (HVA), 3-methoxyl-4-hydroxyphenylenglycol, 5-hydroxy-indolacetic acid (5-HIAA), and 3, 4-dihydroxyphenylacetic acid in the whole cerebral cortex, the thalamus and hypothalamus, the midbrain, the lower brainstem, the cerebellum, and the striatum. Fluorohistochemical studies were also performed. Significant improvements were observed in body proportion and coordination movement in the ventriculoperitoneal shunt group compared to the burr hole group and the no treatment group. HPLC and fluorohistochemical studies revealed that concentrations of NE in the thalamus and hypothalamus and DA in the striatum were significantly lower in the burr hole group and the no treatment group. Concentrations of HVA and 5-HIAA in the cerebellum were significantly lower in the control group. The present study indicates that ventriculoperitoneal shunting may improve the changes in concentrations of neurotransmitter in specific neurons caused by hydrocephalus, and this may contribute to the improvement of the symptoms.