Linked Life Data

17045752

Source:http://linkedlifedata.com/resource/pubmed/id/17045752

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-12-12
pubmed:abstractText
Extracellular recordings were made from output neurons in the dorsal half of the periaqueductal gray matter (dPAG) in urethane-anesthetized female Wistar rats. All the neurons were quiescent. A basal level of firing was therefore induced by continuous iontophoretic application of D,L-homocysteic acid (DLH). In the presence of the GABA(A) receptor antagonist bicuculline methiodide (BIC 0-30 nA) the DLH-induced firing increased further, revealing the presence of ongoing GABAergic inhibitory tone on the recorded neurons. The BIC-induced increase in firing rate was significantly greater in neurons recorded during estrus (Est) and late diestrus (LD) compared with proestrus (Pro) and early diestrus (ED) suggesting that GABAergic tone was lower in Est and LD. I.v. injection of the panicogenic cholecystokinin (CCK)(B) receptor agonist pentagastrin (PG, 40 microg kg(-1)) produced an increase in firing rate in 12/17 (70%) of neurons tested in the dPAG. Iontophoretic application of PG (10-30 nA) also produced a current-related increase in firing rate in 73.6% of the neurons tested. The excitatory response was reduced during application of the selective CCK(B) receptor antagonist beta-[2-([2-(8-azaspiro[4.5]dec-8-ylcarbonyl)-4,6-dimethylphenyl]amino)-2-oxoethyl]-(R)-napthalenepropanoic acid (CR2945) (60 nA, n=6). The PG-evoked increase in firing rate was significantly greater in neurons recorded during Est and LD compared with during Pro and ED. Juxtacellular labeling with neurobiotin in eight neurons revealed multipolar cells 12-44 microm diameter with up to six primary dendrites. In three of eight neurons, a filled axon was present and coursed without branching toward the perimeter of the periaqueductal gray matter (PAG). The estrous cycle-related change in responsiveness to BIC and PG suggests that the panic circuitry in the PAG may become more responsive to panicogenic agents during estrus and late diestrus as a consequence of a decrease in the intrinsic level of inhibitory GABAergic tone. The findings may have implications for understanding the neural processes that underlie the development of premenstrual dysphorias in women.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
325-35
pubmed:dateRevised
2007-8-13
pubmed:meshHeading
pubmed-meshheading:17045752-Anesthesia, pubmed-meshheading:17045752-Animals, pubmed-meshheading:17045752-Bicuculline, pubmed-meshheading:17045752-Biotin, pubmed-meshheading:17045752-Blood Pressure, pubmed-meshheading:17045752-Electrophysiology, pubmed-meshheading:17045752-Estrous Cycle, pubmed-meshheading:17045752-Female, pubmed-meshheading:17045752-GABA Antagonists, pubmed-meshheading:17045752-Heart Rate, pubmed-meshheading:17045752-Immunohistochemistry, pubmed-meshheading:17045752-Injections, Intravenous, pubmed-meshheading:17045752-Microelectrodes, pubmed-meshheading:17045752-Neurons, pubmed-meshheading:17045752-Panic Disorder, pubmed-meshheading:17045752-Pentagastrin, pubmed-meshheading:17045752-Periaqueductal Gray, pubmed-meshheading:17045752-Phenotype, pubmed-meshheading:17045752-Rats, pubmed-meshheading:17045752-Rats, Wistar, pubmed-meshheading:17045752-Tissue Fixation, pubmed-meshheading:17045752-gamma-Aminobutyric Acid
pubmed:year
2007
pubmed:articleTitle
Neuronal excitability in the periaqueductal grey matter during the estrous cycle in female Wistar rats.
pubmed:affiliation
Department of Physiology, University of Birmingham, Birmingham B15 2TT, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't