Gabaergic neurons of the hippocampus: development in homotopic grafts and in dissociated cell cultures.

The hippocampus taken from E18-E19 rat embryos was dissociated into a cell suspension and was either grafted into the hippocampus of adult rats or cultured. The growth of GABAergic neurons was examined using a GABA directed antiserum. The implanted tissue was capable of survival and growth without exhibiting a laminar organization. Most of the various morphological neuronal types could be observed, establishing different types of synapses; however, granule neurons were rarely encountered. A substantial proportion of GABA-positive neurons was detected within the graft with profuse labelling of the neuropil. In cultures issued from the same cell suspension, GABA-immunoreactive neurons were numerous and had different morphologies. Altogether these data suggest that GABA neurons express a high potential for growth and sprouting in vitro and in vivo.