Cerebellar slice cultures from mice lacking the P/Q calcium channel: electroresponsiveness of Purkinje cells.
To investigate the role of P/Q type Ca(2+) channels in determining the firing pattern of Purkinje cells (PCs) we compared the somatically evoked discharge of action potentials (APs) in PCs from 3 to 4 week old cerebellar slice cultures obtained with ataxic mice lacking alpha(1A)-subunit (alpha(-/-)) and with normal mice (non-ataxic alpha(+/-) or alpha(+/+)) using the whole-cell configuration of the patch-clamp recording method. Whereas evoked responses of PCs in normal mice were mainly fast APs, those of PCs from ataxic mice were mainly low-threshold Ca(2+) spikes (LTS). Furthermore, a sustained plateau potential due to the activation of cadmium sensitive Ca(2+) conductances was not observed in PCs from ataxic mice by blocking K(+) channels. These results confirm that P/Q Ca(2+) channels elicit Ca(2+)-dependent plateau potentials and control the propagation of the dendritic LTS to the soma.
Cavelier
Pauline
P
Laboratoire de Neurotransmission et Sécrétion Neuroendocrine, CNRS UPR 2356, Centre de Neurochimie, 5 rue Blaise Pascal, F-67084 Strasbourg Cedex, France.
Beekenkamp
Huguette
H
Shin
Hee-Sup
HS
Jun
Kisun
K
Bossu
Jean-Louis
JL
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D020864:Calcium Channels, N-Type / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology; D002531:Cerebellum / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009924:Organ Culture Techniques; D010477:Perfusion; D011689:Purkinje Cells / Q000502:physiology*
D020864:Calcium Channels, N-Type