GLUTAMATE DEPENDENT DENDRITIC OUTGROWTH IN DEVELOPING NEURONAL NETWORKS OF RAT HIPPOCAMPAL CELLS IN-VITRO

The present study was undertaken to determine whether release of gluta mate is capable of influencing dendritic morphology in a developing ne twork of rat hippocampal neurons in vitro. Control cultures developed a dense network of fibers and evinced spontaneous electrical activity from the third day in vitro. Dendrites were examined in cultures maint ained for 2 weeks in vitro: the experimental group grown in medium con taining the glutamate receptor antagonists AP-5 and DNQX. Dendritic ex tensions were analyzed as a function of time (days in vitro) using a n umber of morphometric parameters, viz. the number of processes, the nu mber and length of intermediate and terminal segments, as well as the total length of all segments. We found that the effect of age and trea tment was most prominently reflected in the length of the terminal seg ments. Chronic addition of ionotropic glutamate receptor antagonists f rom day 2 in culture arrested all dendrite parameters at the prefuncti onal level. The results suggest that glutamate release is crucial for the onset of dendritic morphological development in hippocampal neuron s. (C) 1997 ISDN.