[Formation of spontaneous and evoked neuronal activity in an organotypic culture of hippocampal tissue].

Spontaneous and evoked neuronal activity was studied with extracellular microelectrodes in the organotypic explants from newborn mouse hippocampus during two first weeks in vitro. Electrical stimuli applied to the entorhinal cortex and fascia dentata evoked short- and long-latency responses in hippocampal neurons beginning from the 5-6th day in vitro. The short latency responses were presumably monosynaptic, the long-lasting ones, polysynaptic. The latter were usually changed by repetitive stimulation. These data suggest that appearence of evoked activity during cultivation reflects the formation in vitro of the perforant path and mossy fibres and the maturation of the synaptic contacts.