Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2004-3-11
pubmed:abstractText
The hippocampus, being sensitive to stress and glucocorticoids, plays significant roles in certain types of learning and memory. Therefore, the hippocampus is probably involved in the increasing drug use, drug seeking, and relapse caused by stress. We have studied the effect of stress with morphine on synaptic plasticity in the CA1 region of the hippocampus in vivo and on a delayed-escape paradigm of the Morris water maze. Our results reveal that acute stress enables long-term depression (LTD) induction by low-frequency stimulation (LFS) but acute morphine causes synaptic potentiation. Remarkably, exposure to an acute stressor reverses the effect of morphine from synaptic potentiation (approximately 20%) to synaptic depression (approximately 40%), precluding further LTD induction by LFS. The synaptic depression caused by stress with morphine is blocked either by the glucocorticoid receptor antagonist RU38486 or by the NMDA-receptor antagonist D-APV. Chronic morphine attenuates the ability of acute morphine to cause synaptic potentiation, and stress to enable LTD induction, but not the ability of stress in tandem with morphine to cause synaptic depression. Furthermore, corticosterone with morphine during the initial phase of drug use promotes later delayed-escape behavior, as indicated by the morphine-reinforced longer latencies to escape, leading to persistent morphine-seeking after withdrawal. These results suggest that hippocampal synaptic plasticity may play a significant role in the effects of stress or glucocorticoids on opiate addiction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
10
pubmed:volume
24
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2412-20
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:15014116-Animals, pubmed-meshheading:15014116-Corticosterone, pubmed-meshheading:15014116-Drug Administration Schedule, pubmed-meshheading:15014116-Electric Stimulation, pubmed-meshheading:15014116-Electrodes, Implanted, pubmed-meshheading:15014116-Escape Reaction, pubmed-meshheading:15014116-Excitatory Amino Acid Antagonists, pubmed-meshheading:15014116-Excitatory Postsynaptic Potentials, pubmed-meshheading:15014116-Hippocampus, pubmed-meshheading:15014116-Long-Term Potentiation, pubmed-meshheading:15014116-Long-Term Synaptic Depression, pubmed-meshheading:15014116-Male, pubmed-meshheading:15014116-Maze Learning, pubmed-meshheading:15014116-Mifepristone, pubmed-meshheading:15014116-Morphine, pubmed-meshheading:15014116-Neuronal Plasticity, pubmed-meshheading:15014116-Opioid-Related Disorders, pubmed-meshheading:15014116-Rats, pubmed-meshheading:15014116-Rats, Sprague-Dawley, pubmed-meshheading:15014116-Reaction Time, pubmed-meshheading:15014116-Stress, Physiological, pubmed-meshheading:15014116-Synapses
pubmed:year
2004
pubmed:articleTitle
Stress enables synaptic depression in CA1 synapses by acute and chronic morphine: possible mechanisms for corticosterone on opiate addiction.
pubmed:affiliation
Laboratory of Learning and Memory, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming 650223, People's Republic of China.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't