Journal
BRAIN RESEARCH
Volume 1024, Issue 1-2, Pages 212-224Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.brainres.2004.07.074
Keywords
voltage-dependent calcium channel current; nucleus tractus solitarius; metabotropic glutamate receptor; protein kinase C; dual modulation
Categories
Ask authors/readers for more resources
It is well known that metabotropic glutamate receptors (mGluRs) have multiple actions on neuronal excitability mediated by G-protein-coupled receptors, although the exact mechanisms by which these actions occur are not understood. This study examines the effects of mGluRs agonists on voltage-dependent Ca2+ channels (VDCCs) currents (I-Ca) in the nucleus tractus solitarius (NTS) of rats using patch-clamp recording methods. An application of (RS)-3,5-dihydroxyphenylglycine (DHPG, Group I mGluR agonist) caused both facilitation and inhibition of L-type and N/P/Q-types I-Ca, respectively. Neither (2S, 2'R, 3'R)-2-(2', 3'-dicarboxycyclopropyl)glycine (DCG, Group II mGluRs agonist) nor L-(+)-2-amino-4-phosphonobutyric acid (AP-4, Group III mGluRs agonist) nor (RS)-2-chloro-5-hydroxyphenylglycine (CHPG, mGluR5 agonist) modulated I-Ca. Intracellular dialysis of the G(i)-protein antibody and Gi-protein antibody attenuated the DHPG-induced facilitation and inhibition, respectively. The phospholipase C (PLC) inhibitor, as well as inhibition of either the protein kinase C (PKC) or inositol-1,4,5-trisphosphate (IP3) attenuated the DHPG-induced facilitation of ICa but not a DHPG-induced inhibition. Application of a strong depolarizing voltage prepulse attenuated the DHPG-induced inhibition of ICa. These results indicate that mGluR1 facilitates L-type VDCCs via G(q/11)-protein involving PKC including IP3 formation. On the other hand, mGluR1 inhibits N- and P/Q-types VDCCs via G(i)-protein betagamma subunits. (C) 2004 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available