Reexamination of the effects of MCPG on hippocampal LTP, LTD, and depotentiation - PubMed (original) (raw)

Reexamination of the effects of MCPG on hippocampal LTP, LTD, and depotentiation

D K Selig et al. J Neurophysiol. 1995 Sep.

Abstract

1. We examined the effects of the metabotropic glutamate receptor (mGluR) antagonist alpha-methyl-4-carboxyphenylglycine (MCPG) on the induction of long-term potentiation (LTP) long-term depression (LTD), and depotentiation in CA1 hippocampal neurons using extracellular recording techniques. 2. MCPG (500 microM) strongly antagonized the presynaptic inhibitory action of the mGluR agonist 1-aminocyclopentane-(1S,3R)-dicarboxylic acid yet failed to block LTP induced with either tetanic stimulation (100 Hz, 1 s) or theta-burst stimulation. 3. To test the possibility that our failure to block LTP was due to prior activation of a "molecular switch" that in its "on" state obviates the need for mGluR activation to generate LTP, we gave repeated periods of prolonged low-frequency stimulation (LFS; 1 Hz, 10 min), a manipulation reported to turn the switch "off." Although this stimulation saturated LTD, subsequent application of MCPG still failed to block LTP. 4. MCPG did not block LFS-induced depotentiation in older slices (4-6 wk) or LFS-induced LTD in older, young (11-18 days), or neonatal (3-7 days) slices. 5. These results demonstrate that MCPG-sensitive mGluRs are not necessary for the induction of LTP, LTD, or depotentiation in hippocampal CA1 pyramidal cells. The possibility remains, however, that their activation may modify the threshold for the induction of these long-term plastic changes.

PubMed Disclaimer

Cited by

Group I metabotropic glutamate receptor signaling via Galpha q/Galpha 11 secures the induction of long-term potentiation in the hippocampal area CA1.
Miura M, Watanabe M, Offermanns S, Simon MI, Kano M. Miura M, et al. J Neurosci. 2002 Oct 1;22(19):8379-90. doi: 10.1523/JNEUROSCI.22-19-08379.2002. J Neurosci. 2002. PMID: 12351712 Free PMC article.
Direct effects of metabotropic glutamate receptor compounds on native and recombinant N-methyl-D-aspartate receptors.
Contractor A, Gereau RW 4th, Green T, Heinemann SF. Contractor A, et al. Proc Natl Acad Sci U S A. 1998 Jul 21;95(15):8969-74. doi: 10.1073/pnas.95.15.8969. Proc Natl Acad Sci U S A. 1998. PMID: 9671788 Free PMC article.
Reversal of age-related alterations in synaptic plasticity by blockade of L-type Ca2+ channels.
Norris CM, Halpain S, Foster TC. Norris CM, et al. J Neurosci. 1998 May 1;18(9):3171-9. doi: 10.1523/JNEUROSCI.18-09-03171.1998. J Neurosci. 1998. PMID: 9547225 Free PMC article.
Molecular mechanisms of group I metabotropic glutamate receptor mediated LTP and LTD in basolateral amygdala in vitro.
Chen A, Hu WW, Jiang XL, Potegal M, Li H. Chen A, et al. Psychopharmacology (Berl). 2017 Feb;234(4):681-694. doi: 10.1007/s00213-016-4503-7. Epub 2016 Dec 28. Psychopharmacology (Berl). 2017. PMID: 28028604
Group 1 and 2 metabotropic glutamate receptors play differential roles in hippocampal long-term depression and long-term potentiation in freely moving rats.
Manahan-Vaughan D. Manahan-Vaughan D. J Neurosci. 1997 May 1;17(9):3303-11. doi: 10.1523/JNEUROSCI.17-09-03303.1997. J Neurosci. 1997. PMID: 9096163 Free PMC article.

Reexamination of the effects of MCPG on hippocampal LTP, LTD, and depotentiation - PubMed (original) (raw)