The dynamics of hippocampal sensory gating during the development of morphine dependence and withdrawal in rats.
The effects of morphine on hippocampal sensory gating (N40) during the development of morphine dependence and withdrawal were investigated in the double click auditory evoked potential (EP) suppression paradigm. Rats were made dependent upon morphine hydrochloride by a series of injections (every 12 h) over 6 days, followed by withdrawal after stopping morphine administration. Hippocampal gating was examined during the development of dependence and withdrawal. Moreover, the DA antagonist haloperidol was used to assess the contribution of dopamine to hippocampal gating induced by morphine. Our results showed that the morphine-treated rats exhibited significantly disrupted hippocampal gating during the development of morphine dependence and this disrupted gating was partially reversed by haloperidol pretreatment. In contrast, there was significantly enhanced hippocampal gating at the fifth and sixth days of withdrawal. The dynamics of hippocampal gating during the development of morphine dependence and withdrawal suggests the interaction between the hippocampus and opioids.
Zheng
Jiawei
J
Laboratory of Cognition and Brain Research, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China. kmjiawei@yahoo.com.cn
Yang
Yan
Y
Tian
Shaohua
S
Chen
Jin
J
Wilson
Fraser A W
FA
Ma
Yuanye
Y
D000161:Acoustic Stimulation; D000701:Analgesics, Opioid / Q000009:adverse effects*; D000818:Animals; D001307:Auditory Perception / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism / Q000502:physiology; D018492:Dopamine Antagonists / Q000494:pharmacology; D004569:Electroencephalography / Q000187:drug effects; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology; D006624:Hippocampus / Q000503:physiopathology*; D009020:Morphine / Q000009:adverse effects*; D009021:Morphine Dependence / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*
D000701:Analgesics, Opioid; D018492:Dopamine Antagonists; D009020:Morphine; D006220:Haloperidol; D004298:Dopamine