NEUROCHEMICAL CHANGES IN THE CEREBRAL-CORTEX OF TREATED AND UNTREATEDHYDROCEPHALIC RAT PUPS QUANTIFIED WITH IN-VITRO H-1-NMR SPECTROSCOPY

The pathophysiology of infantile hydrocephalus is poorly understood, a nd shunt treatment does not always lead to a normal neurological outco me. To investigate some of the neurochemical changes in infantile hydr ocephalus and the response to shunt treatment, we have used high-resol ution H-1-NMR spectroscopy to analyze extracts of cerebral cortex from H-Tx rats, which have inherited hydrocephalus with an onset in late g estation. Hydrocephalic rats and rats with shunts placed at either 4 o r 12 days after birth were studied at 21 days after birth, together wi th age-matched control littermates. In hydrocephalic rats there was a 46-62% reduction in the following compounds: myo-inositol, creatine, c holine-containing compounds, N-acetyl aspartate, taurine, glutamine, g lutamate, aspartate, and alanine. Phosphocreatine, glycine, GABA, and lactate were also reduced but not significantly. These changes are con sistent with neuronal atrophy rather than ischemic damage. In hydrocep halic rats that received shunt treatment at 4 days, there were no sign ificant reductions in any chemicals, indicating a normal complement of neurons. However, some compounds, particularly taurine; were elevated above control. After treatment at 12 days, N-acetyl aspartate and asp artate remained significantly reduced, suggesting continued neuronal d eficiency.