Format

Send to

Choose Destination
Neuron. 1995 Sep;15(3):675-88.

Calcium control of transmitter release at a cerebellar synapse.

Author information

1
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.

Abstract

The manner in which presynaptic Ca2+ influx controls the release of neurotransmitter was investigated at the granule cell to Purkinje cell synapse in rat cerebellar slices. Excitatory postsynaptic currents were measured using whole-cell voltage clamp, and changes in presynaptic Ca2+ influx were determined with the Ca(2+)-sensitive dye furaptra. We manipulated presynaptic Ca2+ entry by altering external Ca2+ levels and by blocking Ca2+ channels with Cd2+ or with the toxins omega-conotoxin GVIA and omega-Aga-IVA. For all of the manipulations, other than the application of omega-Aga-IVA, the relationship between Ca2+ influx and release was well approximated by a power law, n approximately 2.5. When omega-Aga-IVA was applied, release appeared to be more steeply dependent on Ca2+ (n approximately 4), suggesting that omega-Aga-IVA-sensitive channels are more effective at triggering release. Based on interactive effects of toxins on synaptic currents, we conclude that multiple types of Ca2+ channels synergistically control individual release sites.

PMID:
7546746
DOI:
10.1016/0896-6273(95)90155-8
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center