Linked Life Data

9449421

Source:http://linkedlifedata.com/resource/pubmed/id/9449421

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1998-2-24
pubmed:abstractText
Paired-pulse depression (PPD) and facilitation are found at many synapses in the central nervous system. In the present study, we aimed to characterise the paired-pulse behaviour of evoked postsynaptic potentials in the superficial layers of slices of the superior colliculus (SC) of adult guinea-pigs. We observed PPD for inter-stimulus intervals between 10 and 500 ms, for both high (90% of maximum) and low (30% of maximum) stimulus intensities. This depression could be converted into a facilitation when the probability of transmitter release was reduced in low Ca2+/high Mg2+ solution, but only when the low stimulus intensity was applied. Elimination of GABA(A) receptor mediated currents by bicuculline caused an enhanced general excitation and enhanced PPD. Application of the GABA(B) receptor antagonist CGP35348 reduced PPD, suggesting the contribution of slow inhibitory postsynaptic currents. The NMDA receptor antagonist D,L-amino-5-phosphonovaleric acid (APV) did not lead to major alterations of PPD. We conclude that presynaptic mechanisms affecting Ca2+-dependent glutamate release are crucial for PPD in the superficial SC. Nevertheless, postsynaptic inhibitory components and probably polysynaptic pathways also seem to contribute to PP behaviour in the SC. Moreover, PPD in the SC has a different profile compared with other brain areas. Here, PPD may be crucially involved in setting the threshold for novel vs. background stimulation, since the SC is known to trigger orienting responses towards novel sensory stimuli.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-8993
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
777
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
131-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Paired-pulse depression in the superficial layers of the guinea-pig superior colliculus.
pubmed:affiliation
Department of Biomedical Sciences, IMS, Aberdeen University, Foresterhill, UK. b.platt@abdn.ac.uk
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't