DEVELOPMENTAL-CHANGES OF INWARD RECTIFIER CURRENTS IN NEURONS OF THE RAT ENTORHINAL CORTEX

A slice preparation was used to investigate inward rectifier currents (I-H) of entorhinal cortex (EC) neurons. Using the whole-cell configur ation of the patch-clamp technique, I-H was studied in pyramidal cells from layer IV of the rat EC and in stellate cells from layer II of th e EC. Inward rectifier currents were analyzed in neurons of newborn (P 1-3), juvenile (P8-14) and adult (>P28) rats. Pyramidal cells of juven ile rats possessed a significantly larger current density of I-H than pyramidal cells of newborn rats, whereas no differences in the current density of I-H were found between pyramidal neurons of juvenile and o f adult animals. In contrast, the current density of I-H of stellate c ells was significantly increased in juvenile rats compared with newbor n rats as well as in adult rats compared with juvenile rats. Moreover, in adult rats the current density of I-H was larger in stellate cells than in pyramidal cells, whereas opposite data were obtained in juven ile animals. (C) 1997 Elsevier Science Ireland Ltd.