Linked Life Data

15212418

Source:http://linkedlifedata.com/resource/pubmed/id/15212418

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2004-10-15
pubmed:abstractText
In the rodent main olfactory bulb (MOB), mitral cells (MCs) express high levels of the group I metabotropic glutamate receptor (mGluR) subtype, mGluR1. The significance of this receptor in modulating MC excitability is unknown. We investigated the physiological role of mGluR1 in regulating MC activity in rat and mouse MOB slices. The selective group I agonist (RS)-3,5-dihydroxyphenylglycine (DHPG), but not group II or III agonists, induced potent, dose-dependent, and reversible depolarization and increased firing of MCs. These effects persisted in the presence of blockers of fast synaptic transmission, indicating that they are due to direct activation of mGluRs on MCs. Voltage-clamp recordings showed that DHPG elicited a voltage-dependent inward current consisting of multiple components sensitive to potassium and calcium channel blockade and intracellular calcium chelation. MC excitatory responses to DHPG were absent in mGluR1 knockout mice but persisted in mGluR5 knockout mice. Broad-spectrum LY341495, MCPG, as well as preferential mGluR1 LY367385 antagonists blocked the excitatory effects of DHPG and also potently modulated MC spontaneous and olfactory nerve-evoked excitability. mGluR antagonists altered spontaneous membrane potential bistability, increasing the duration of the up and down states. mGluR antagonists also substantially attenuated MC responses to sensory input, decreasing the probability and increasing the latency of olfactory nerve-evoked spikes. These findings suggest that endogenous glutamate tonically modulates MC excitability and responsiveness to olfactory nerve input, and hence the operation of the MOB circuitry, via activation of mGluR1.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
92
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3085-96
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Regulation of main olfactory bulb mitral cell excitability by metabotropic glutamate receptor mGluR1.
pubmed:affiliation
Department of Physiology and Program Neuroscience, University of Maryland School of Medicine, 655 W. Baltimore St., Baltimore, MD 21201, USA. thein001@umaryland.edu
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't