Send to

Choose Destination
Eur J Neurosci. 2000 Mar;12(3):987-93.

The retrograde inhibition of IPSCs in rat cerebellar purkinje cells is highly sensitive to intracellular Ca2+.

Author information

Arbeitsgruppe Zelluläre Neurobiologie, Max-Planck-Institut für biophysikalische Chemie, Am Fassberg, 37070, Göttingen, Germany.


The Ca2+-dependent retrograde inhibition of inhibitory postsynaptic currents (depolarization-induced-suppression of inhibition; DSI) was investigated using fura-2 Ca2+ measurements and whole-cell patch-clamp recordings in rat cerebellar Purkinje cells. DSI was studied in cells loaded with different concentrations of the Ca2+ chelators BAPTA and EGTA. A concentration of 40 mM BAPTA was required to significantly interfere with DSI, whereas 10 mM BAPTA was almost ineffective. 40 mM EGTA reduced DSI, but was less effective than 40 mM BAPTA. Ratiometric Ca2+ measurements indicated that the extent of DSI depended critically on the changes in intracellular calcium ([Ca2+]i). The relationship between DSI and peak Delta[Ca2+]i could be approximated by a hyperbolic function, with apparent half-saturation concentrations of 200 and 40 nM for dendritic and somatic [Ca2+]i, respectively. It is suggested that DSI is due to somatodendritic exocytosis of a retrograde messenger, and that this exocytosis is highly sensitive to [Ca2+]i.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center