Intrastriatal and intrasubthalamic stimulation of metabotropic glutamate receptors: A behavioral and Fos immunohistochemical study

AbstractIntrinsic interneurons within the dorsal lateral geniculate nucleus (dLGN) provide a feed-forward inhibitory pathway for afferent visual information originating from the retina. These interneurons are unique because in addition to traditional axodendritic output onto thalamocortical neurons, these interneurons have presynaptic dendrites that form dendrodendritic synapses onto thalamocortical neurons as well. These presynaptic dendrites, termed F2 terminals, are tightly coupled to the retinogeniculate afferents that synapse onto thalamocortical relay neurons. Retinogeniculate stimulation of F2 terminals can occur through the activation of ionotropic and/or metabotropic glutamate receptors. The stimulation of ionotropic glutamate receptors can occur with single stimuli and produces a short-lasting inhibition of the thalamocortical neuron. By contrast, activation of metabotropic glutamate receptors requires tetanic activation and results in longer-lasting inhibition in the thalamocortical neuron. The F2 terminals are predominantly localized to the distal dendrites of interneurons, and the excitation and output of F2 terminals can occur independent of somatic activity within the interneuron thereby allowing these F2 terminals to serve as independent processors, giving rise to focal inhibition. By contrast, strong transient depolarizations at the soma can initiate a backpropagating calcium-mediated potential that invades the dendritic arbor activating F2 terminals and leading to a global form of inhibition. These distinct types of output, focal versus global, could play an important role in the temporal and spatial roles of inhibition that in turn impacts thalamocortical information processing.

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Stimulation of High-Affinity GTPase Activity Through Group II Metabotropic Glutamate Receptors in Rat Hippocampal and Striatal Membranes

The Japanese Journal of Pharmacology ◽

10.1254/jjp.84.399 ◽

2000 ◽

Vol 84 (4) ◽

pp. 399-404 ◽

Cited By ~ 1

Author(s):

Yuji Odagaki ◽

Nobuyuki Nishi ◽

Tsukasa Koyama

Keyword(s):

Glutamate Receptors ◽

Metabotropic Glutamate Receptors ◽

Gtpase Activity ◽

Metabotropic Glutamate ◽

High Affinity ◽

Group Ii ◽

Stimulation Of

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Pharmacological Stimulation of Group II Metabotropic Glutamate Receptors Reduces Cocaine Self-Administration and Cocaine-Induced Reinstatement of Drug Seeking in Squirrel Monkeys

Journal of Pharmacology and Experimental Therapeutics ◽

10.1124/jpet.106.105387 ◽

2006 ◽

Vol 318 (2) ◽

pp. 922-931 ◽

Cited By ~ 64

Author(s):

A. S. Adewale ◽

D. M. Platt ◽

R. D. Spealman

Keyword(s):

Glutamate Receptors ◽

Metabotropic Glutamate Receptors ◽

Squirrel Monkeys ◽

Self Administration ◽

Drug Seeking ◽

Metabotropic Glutamate ◽

Pharmacological Stimulation ◽

Group Ii ◽

Stimulation Of

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Stimulation of N-methyl-d-aspartate receptors, AMPA receptors or metabotropic glutamate receptors leads to rapid internalization of AMPA receptors in cultured nucleus accumbens neurons

European Journal of Neuroscience ◽

10.1111/j.1460-9568.2004.03511.x ◽

2004 ◽

Vol 20 (3) ◽

pp. 649-657 ◽

Cited By ~ 25

Author(s):

Simona Mangiavacchi ◽

Marina E. Wolf

Keyword(s):

Nucleus Accumbens ◽

Glutamate Receptors ◽

Ampa Receptors ◽

Metabotropic Glutamate Receptors ◽

Metabotropic Glutamate ◽

Stimulation Of

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Stimulation of metabotropic glutamate receptors in the dorsomedial hypothalamus elevates heart rate in rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1996.270.5.r1115 ◽

1996 ◽

Vol 270 (5) ◽

pp. R1115-R1121 ◽

Cited By ~ 1

Author(s):

J. DiMicco ◽

A. J. Monroe

Keyword(s):

Heart Rate ◽

Glutamate Receptors ◽

Metabotropic Glutamate Receptors ◽

Cardiovascular Effects ◽

Nmda Receptor Antagonist ◽

Dorsomedial Hypothalamus ◽

Metabotropic Glutamate ◽

Selective Blockade ◽

Stimulation Of

This study examined the potential role of metabotropic glutamate receptors (mGluRs) in the dorsomedial hypothalamus (DMH) by assessing the cardiovascular effects of microinjecting the agonist trans-1-aminocyclopentane-1, 3- dicarboxylate (tACPD) into this region in urethan-anesthetized rats. Dose-related tachycardia was observed after unilateral microinjection of 1S 3R-tACPD (10-200 pmol/50nl) but not after injection of 1R, 3S-tACPD, which has been reported to have little or no activity at mGluRs. Microinjection of dihydroxyphenylglycine, an agonist at mGluRs linked to phosphoinositide hydrolysis, resulted in increases in heart rate that correlated closely in magnitude to those seen after injection of the same dose of 1S, 3R-tACPD. Coinjection of the N-methyl-D-aspartate (NMDA) receptor antagonist DL-2- amino-5-phosphonopentanoic acid, given at doses shown to elicit selective blockade of NMDA ionotropic glutamate receptors, reduced the increase in heart rate evoked by 100 pmol 1S, 3R-tACPD alone. Thus the DMH contains functional mGluRs, and stimulation of these receptors activates the same sympathoexcitatory mechanism characterized previously to provoke dose-related tachycardia.

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