Metabotropic glutamate receptor modulation of voltage-gated Ca2+ channels involves multiple receptor subtypes in cortical neurons.

Content Provider	Semantic Scholar
Author	Choi, Su-Mi Lovinger, David M.
Copyright Year	1996
Abstract	Metabotropic glutamate receptor (mGluR) modulation of voltage-gated Ca2+ channels was examined in isolated deep layer frontoparietal cortical neurons under conditions designed to isolate calcium-independent modulatory pathways. Trans-1-aminocyclopentane-1,3-dicarboxylate (t-ACPD), a nonspecific mGluR agonist, produced rapid and reversible inhibition of Ca2+ channels. This effect was mimicked by agonists for group I and group II, but not group III, mGluRs. Effects of group I and II agonists often were observed in the same neurons, but separate subgroups of neurons were unresponsive to the group I agonist quisqualate or the group II agonist 2-(2,3-dicarboxycyclopropyl) glycine (DCG-IV). Inhibition by quisqualate and DCG-IV was nonocclusive in neurons responding to both agonists. These agonists thus appear to act on different mGluRs. The mGluR antagonist alpha-methyl-4-carboxylphenylglycine attenuated inhibition by t-ACPD, quisqualate, and DCG-IV. Inhibition by quisqualate and DCG-IV was voltage-dependent. Although the effects of both agonists were greatly reduced by N-ethylmaleimide (NEM), inhibition by DCG-IV was more sensitive to NEM than inhibition by quisqualate. t-ACPD-induced inhibition was reduced by omega-conotoxin GVIA (omega-CgTx) and omega-agatoxin IVA (omega-AgTx) but was affected little by nifedipine. Inhibition by DCG-IV and quisqualate also was reduced by omega-CgTx. We conclude that multiple mGluR subtypes inhibit Ca2+ channels in cortical neurons and that N- and possibly P-type channels are inhibited. Modulation is via a rapid-onset, voltage-dependent mechanism that likely involves a pertussis toxin (PTX)-sensitive G-protein. Type I mGluRs may work via additional PTX-insensitive pathways.
Starting Page	36
Ending Page	45
Page Count	10
File Format	PDF HTM / HTML
DOI	10.1523/JNEUROSCI.16-01-00036.1996
PubMed reference number	8613803
Journal	Medline
Volume Number	16
Issue Number	1
Alternate Webpage(s)	http://www.jneurosci.org/content/jneuro/16/1/36.full.pdf
Alternate Webpage(s)	https://doi.org/10.1523/JNEUROSCI.16-01-00036.1996
Journal	The Journal of neuroscience : the official journal of the Society for Neuroscience
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article