The functional outcome of shunting H-Tx rat pups at different ages

'Normal', untreated hydrocephalic and CSF shunted hydrocephalic Texas (H-Tx) rat pups at different ages and Sprague-Dawley controls were tested for spatial learning and memory acquisition in an 8-arm radial maze. Shunting 5 day old hydrocephalic pups improved their performance to 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 the Sprague-Dawley controls. These findings suggest that shunting prior to skull plate fusion, which occurs at approximately the tenth postnatal day, is capable of protecting brain function involved in memory and learning. The poor functional scores achieved by the 'normal' as well as the treated and untreated H-Tx animals compared to the control Sprague-Dawleys, raises the possibility that the H-Tx rat has brain deficits in addition to those caused by hydrocephalus.