Synapse formation and spontaneous activity in rat brainstem neurons in primary culture.
The correlation between synaptogenesis and onset of spontaneous action potentials was assessed in rat brainstem cells up to 29 days in primary culture. Cells exhibited different stages of maturation followed by electron microscopy and patch clamp recordings. Terminal boutons with no preferential orientation of presynaptic vesicles appeared after 2 days in culture. After 5 days, preferential orientation of presynaptic vesicles and thickening of postsynaptic membranes were observed. The spontaneous discharge of action potentials, single or bursting, was observed after 7 days in vitro. This was followed by the expression of a 128-pS K(+) channel starting at 13 days in vitro. A 69-pS K(+) channel was also present throughout the duration of the cultures. These results suggest that spontaneous discharge of action potentials does not occur before synapses are formed and K(+) channel types develop differentially in brainstem neurons in vitro.
Guinamard
R
R
Laboratoire de biologie fonctionnelle du neurone, Institut Alfred Fessard, CNRS, 1 Av de la Terrasse, 91198 Gif sur Yvette Cx, France.
Delpy
E
E
Denizot
J P
JP
Jacquin
T D
TD
D000200:Action Potentials; D000818:Animals; D001933:Brain Stem / Q000166:cytology* / Q000196:embryology*; D002454:Cell Differentiation; D016764:Cell Polarity; D002478:Cells, Cultured; D004553:Electric Conductivity; D005260:Female; D009474:Neurons / Q000166:cytology / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure*; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
D015221:Potassium Channels