Linked Life Data

8071665

Source:http://linkedlifedata.com/resource/pubmed/id/8071665

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1994-9-26
pubmed:abstractText
We have been investigating the hypothesis that the membrane-permeant molecules nitric oxide (NO) and carbon monoxide (CO) may act as retrograde messengers during long-term potentiation (LTP). Inhibitors of either NO synthase or heme oxygenase, the enzyme that produces CO, blocked induction of LTP in the CA1 region of hippocampal slices. Brief application of either NO or CO to slices produced a rapid and long-lasting increase in the size of synaptic potentials if, and only if, the application occurred at the same time as weak tetanic stimulation of the presynaptic fibers. The long-term enhancement by NO or CO was spatially restricted to synapses from active presynaptic fibers and appeared to involve mechanisms utilized by LTP, occluding the subsequent induction of LTP by strong tetanic stimulation. The enhancement by NO or CO was not blocked by the NMDA receptor blocker APV, suggesting that NO and CO act downstream from the NMDA receptor. In other systems, both NO and CO produce many of their effects by activation of soluble guanylyl cyclase and cGMP-dependent protein kinase. An inhibitor of soluble guanylyl cyclase blocked the induction of normal LTP. Conversely, the membrane-permeable analog 8-Br-cGMP produced a rapid onset and long-lasting synaptic enhancement if, and only if, it was applied at the same time as weak presynaptic stimulation. Similarly, two inhibitors of cGMP-dependent protein kinase blocked the induction of normal LTP, and a selective activator of cGMP-dependent protein kinase produced activity-dependent long-lasting synaptic enhancement. 8-Br-cGMP also produced an activity-dependent, long-lasting increase in the amplitude of evoked synaptic currents between pairs of hippocampal neurons in dissociated cell culture. In addition, 8-Br-cGMP, like NO, produced a long-lasting increase in the frequency of spontaneous miniature synaptic currents. These results are consistent with the hypothesis that NO and CO, either alone or in combination, serve as retrograde messengers that produce activity-dependent presynaptic enhancement, perhaps by stimulating soluble guanylyl cyclase and cGMP-dependent protein kinase, during LTP in hippocampus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3034
pubmed:author
pubmed:issnType
Print
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
652-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Nitric oxide and carbon monoxide as possible retrograde messengers in hippocampal long-term potentiation.
pubmed:affiliation
Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, Non-U.S. Gov't