TRPC-Mediated Current Is Not Involved in Endocannabinoid-Induced Short-Term Depression in Cerebellum.
10.4196/kjpp.2012.16.2.139
- Author:
Wonseok CHANG
1
;
Joo Min PARK
;
Jun KIM
;
Sang Jeong KIM
Author Information
1. Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea. sangjkim@snu.ac.kr
- Publication Type:Original Article
- Keywords:
Endocannabinoid;
TRPC;
Short-term depression;
Cerebellar Purkinje cell;
BTP2
- MeSH:
Calcium;
Calcium Signaling;
Cerebellum;
Depression;
Endocannabinoids;
Imidazoles;
Purkinje Cells;
Receptors, Metabotropic Glutamate;
Synapses;
Synaptic Transmission
- From:The Korean Journal of Physiology and Pharmacology
2012;16(2):139-144
- CountryRepublic of Korea
- Language:English
-
Abstract:
It has been reported that activation of metabotropic glutamate receptor 1 (mGluR1) can mediate endocannabinoid-induced short-term depression of synaptic transmission in cerebellar parallel fiber (PF)-Purkinje cell (PC) synapse. mGluR1 has signaling pathways involved in intracellular calcium increase which may contribute to endocannabinoid release. Two major mGluR1-evoked calcium signaling pathways are known: (1) slow-kinetic inward current carried by transient receptor potential canonical (TRPC) channel which is permeable to Ca2+; (2) IP3-induced calcium release from intracellular calcium store. However, it is unclear how much each calcium source contributes to endocannabinoid signaling. Here, we investigated whether calcium influx through mGluR1-evoked TRPC channel contributes to endocannabinoid signaling in cerebellar Purkinje cells. At first, we applied SKF96365 to inhibit TRPC, which blocked endocannabinoid-induced short-term depression completely. However, an alternative TRP channel inhibitor, BTP2 did not affect endocannabinoid-induced short-term depression although it blocked mGluR1-evoked TRPC currents. Endocannabinoid signaling occurred normally even though the TRPC current was mostly blocked by BTP2. Our data imply that TRPC current does not play an important role in endocannabinoid signaling. We also suggest precaution in applying SKF96365 to inhibit TRP channels and propose BTP2 as an alternative TRPC inhibitor.
