Linked Life Data

9152403

Source:http://linkedlifedata.com/resource/pubmed/id/9152403

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-6-12
pubmed:abstractText
The effects of N-methyl-D-aspartate receptor blockade on two major variants of rabbit eyeblink conditioning were evaluated using a selective noncompetitive antagonist, [5R, 10S]-[+]-5-methyl-10, 11-dihydro-5H-dibenzo[a, d] cyclo-hepten-5,10-imine hydrogen maleate; dizocilpine (MK-801) or phencyclidine (PCP), a drug of abuse. Either MK-801 or PCP (given daily) impaired rabbits' ability to associate tone conditioned stimuli with airpuff unconditioned stimuli, with the severity of impairment exhibiting clear dose and task dependencies. Trace-conditioned rabbits given > or = 80 micrograms/kg of MK-801 or > or = 1.0 mg/kg of PCP failed to reach a criterion of 80% conditioned responses during training, with significant impairments seen at intermediate doses. Delay-conditioned rabbits, although dose-dependently slowed, successfully acquired the task, even when given doses of MK-801 or PCP that completely blocked acquisition in trace conditioning. Additionally, even low doses of MK-801 (10 micrograms/kg) or of PCP (0.1 mg/kg) severely altered conditioned response timing in trace but not in delay conditioning, resembling effects observed after hippocampal lesions. Doses of MK-801 or PCP that impaired acquisition also severely impaired extinction of both trace- and delay-conditioned eyeblink responses. However, neither MK-801 nor PCP altered retention or timing of previously learned responses. Higher doses of MK-801 (> or = 200 micrograms/kg) or of PCP (> or = 2.0 mg/kg) dose-dependently impaired unconditioned response performance, although lower doses of MK-801 (< or = 160 micrograms/kg) or of PCP (< or = 1.0 mg/kg) had no effects on unconditioned responses or on non-associative pseudoconditioned responses. The deficits observed indicate that although not necessary for retention, N-methyl-D-aspartate receptor activation may facilitate acquisition of delay-conditioning. N-methyl-D-aspartate receptor activation appears to be necessary for acquisition of trace conditioning, and for extinction in either paradigm.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
928-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
N-methyl-D-aspartate receptors in associative eyeblink conditioning: both MK-801 and phencyclidine produce task- and dose-dependent impairments.
pubmed:affiliation
Department of Cell and Molecular Biology, Northwestern University Medical School, Chicago, Illinois, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.