Linked Life Data

7474527

Source:http://linkedlifedata.com/resource/pubmed/id/7474527

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-11-28
pubmed:abstractText
GABA-induced currents were recorded in cone-driven horizontal cells dissociated from the catfish, using the patch clamp technique in the whole-cell configuration. GABA-induced current consisted of two components; approximately 80% of the current was blocked by 100 microM picrotoxin (PTX), and the remaining 20% of the current was blocked when extracellular Na+ was replaced with Li+ or choline. The PTX-sensitive current was carried by Cl-. When methanesulfonate was substituted for the intrapipette Cl-, the reversal potentials of the PTX-sensitive current shifted to a more negative potential close to the Cl- equilibrium potential. The PTX-sensitive current was unaffected either by bicuculline (up to 500 microM), pentobarbital (100 microM), or diazepam (100 microM). These observations suggest that the PTX-sensitive current is not mediated via GABAA receptors. Baclofen, a GABAB receptor agonist, had no effect, suggesting the absence of GABAB receptors. Cis- or trans-4-aminocrotonic acid (CACA and TACA), GABAC receptor agonists, evoked currents in a dose-dependent manner. The potency sequence was TACA > GABA > muscimol > CACA. These observations suggest that the PTX-sensitive current of cone-driven horizontal cells is carried via the GABAC receptor channel. The Cl- equilibrium potential in intact cells was estimated to be approximately -30 mV by recording the GABA-induced voltage response of dissociated cells with a conventional intracellular microelectrode. The intracellular Cl- concentration seemed to be approximately 40 mM. From these results, it is suggested that GABAC receptor channels shape the kinetics of light-induced responses of horizontal cells, and mediate a chemical coupling between neighboring horizontal cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0021-521X
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
437-56
pubmed:dateRevised
2007-3-21
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
GABA-induced chloride current in catfish horizontal cells mediated by non-GABAA receptor channels.
pubmed:affiliation
Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't