Format

Send to

Choose Destination
J Physiol. 1998 Nov 15;513 ( Pt 1):149-55.

Facilitation of presynaptic calcium currents in the rat brainstem.

Author information

1
Abteilung Zellphysiologie, Max-Planck-Institut fur medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany. borst@sunny.mpimf-heidelberg.mpg.de

Abstract

1. To study use-dependent changes in the presynaptic Ca2+ influx and their contribution to transmitter release, we made simultaneous voltage clamp recordings from presynaptic terminals (the calyces of Held) and postsynaptic cells (the principal cells of the medial nucleus of the trapezoid body) in slices of the rat auditory brainstem. 2. Following a short (2 ms) prepulse to 0 mV, calcium channels opened faster during steps to negative test potentials. During trains of action potential waveforms the Ca2+ influx per action potential increased. At the same time, however, the amplitude of the EPSCs decreased. 3. The facilitation of the calcium currents appeared to depend on a build-up of intracellular Ca2+, since its magnitude was proportional to the Ca2+ influx and it was reduced in the presence of 10 mM BAPTA. 4. Facilitation of the presynaptic calcium currents may contribute to short-term facilitation of transmitter release, observed when quantal output is low. Alternatively, it may counteract processes that contribute to synaptic depression.

PMID:
9782166
PMCID:
PMC2231257
DOI:
10.1111/j.1469-7793.1998.149by.x
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center