Multiple components of Ca2+ channel facilitation in cerebellar granule cells:expression of facilitation during development in culture


The contribution of pharmacologically distinct Ca2+ channels to prepulse-induced facilitation was studied in mouse cerebellar granule cells. Ca2+ channel facilitation was measured as the percentage increase in the whole-cell current recorded during a test pulse before and after it was paired with a positive prepulse. The amount of facilitation was small in recordings made during the first few days in tissue culture but increased substantially after 1 week. L-type channels accounted for the largest proportion of facilitation in 1-week-old cells (60-70%), whereas N-type channels contributed very little (approximately 3%). The toxins omega-agatoxin IVa or omega-conotoxin MVIIC (after block of N-, L-, and P-type channels) each blocked a small percentage of facilitation (approximately 12 and 14%, respectively). Perfusion of cells with GTP-gamma-S enhanced the facilitation of N-type channels, whereas it inhibited of L-type channels. During development in vitro, the contribution of L-type channels to the whole-cell current decreased. Single-channel recordings showed the presence of 10 and 15 pS L-type Ca2+ channels in 1-d-old cells. After 1 week in culture, a approximately 25 pS L-type channel dominated recordings from cell-attached patches. Positive prepulses increased the activity of the 25 pS channel but not of the smaller conductance channels. The expression of Ca(2+) channel facilitation during development may contribute to changes in excitability that allow frequency-dependent Ca(2+) influx during the period of active synaptogenesis

Publication DOI:
Divisions: College of Health & Life Sciences > Aston Pharmacy School
College of Health & Life Sciences > Clinical and Systems Neuroscience
College of Health & Life Sciences
Additional Information: Copyright © 1996 Society for Neuroscience. Articles are released under a Creative Commons Attribution License after a 6 months embargo
Uncontrolled Keywords: Animals,Calcium Channels,Cell Aging,Cells, Cultured,Cerebellum,Dihydropyridines,Guanosine 5'-O-(3-Thiotriphosphate),Mice,Neurons,Phosphorylation
Publication ISSN: 1529-2401
Full Text Link:
Related URLs: http://www.jneu ... tent/16/16/4890 (Publisher URL)
PURE Output Type: Article
Published Date: 1996-08-15
Authors: Parri, H R (ORCID Profile 0000-0002-1412-2688)
Lansman, J B



Version: Published Version

License: Creative Commons Attribution

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