THE FUNCTIONAL OUTCOME OF SHUNTING H-TX RAT PUPS AT DIFFERENT AGES

''Normal'', untreated hydrocephalic and CSF shunted hydrocephalic Texa s (H-Tx) rat pups at different ages and Sprague-Dawley controls were t ested for spatial teaming and memory acquisition in an 8-arm radial ma ze. Shunting 5 day old hydrocephalic pups improved their performance t o the level of that of ''normal'' littermates, whereas shunting at 10 days produced no improvement, and the performance of these animals was comparable to that of the untreated hydrocephalics. None of the H-Tx rats, whether treated, untreated or ''normal'', performed as well as t he Sprague-Dawley controls. These findings suggest that shunting prior to skull plate fusion, which occurs at approximately the tenth postna tal day, is capable of protecting brain function involved in memory an d learning. The poor functional scores achieved by the ''normal'' as w ell as the treated and untreated H-Tx animals compared to the control Sprague-Dawleys, raises the possibility that the H-Tx rat has brain de ficits in addition to those caused by hydrocephalus.