Emergence of a synaptic neuronal network within primary striatal cultures seeded in serum-free medium.
In order to investigate the basic cellular mechanisms involved in neuronal interactions within the striatum, we prepared a primary striatal cell culture from rat fetal brain in chemically defined medium. Using morphological and whole-cell recording methods, we observed that an intensive neuritic elongation with a progressive build up of a sodium-dependent electrogenesis occurred during the first week of culture. Morphologically mature synapses began to develop after 10 days in vitro. By this time, most of the neurons (82 +/- 9%) received spontaneously synaptic potentials, which led them to fire (71 +/- 11%). The spontaneous firing was prevented by cadmium (200 microM) and tetrodotoxin (5 microM), which suggested that a Ca(2+)-dependent release of neurotransmitters was involved in the synaptic activation. We further obtained evidence that GABA, and to a lesser extent acetylcholine, contributed to these spontaneous synaptic potentials. At 15 days in vitro, it was possible to observe up to four synaptic contacts on a given dendrite. By this time, whole-cell recordings performed on pairs of neurons showed that the mature neurons were interconnected by excitatory synapses. As the number of synapses increased, the striatal neurons gradually formed a large network in which spontaneous activity developed, which tended to be organized into synchronized bursting patterns.
Kowalski
C
C
Laboratoire de Neurobiologie Cellulaire et Fonctionnelle, CNRS UPR 9013, Marseille, France.
Crest
M
M
Vuillet
J
J
Pin
T
T
Gola
M
M
Nieoullon
A
A
D000200:Action Potentials; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000502:physiology*; D004594:Electrophysiology; D008854:Microscopy, Electron; D009415:Nerve Net; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D005680:gamma-Aminobutyric Acid; D001640:Bicuculline