EEG, EMG and behavioral evidence for the involvement of endorphin systems in postictal events after electroconvulsive shock in rats.
We studied the effects of transauricular electroshock (ECS) on EEG and EMG patterns, and overt behaviors (wet-dog shaking and excessive grooming), caused by RX 336-M (7,8-dihydro-5',6'-dimethylcyclohex-5'-eno-1',2', 8',14 codeinone) in rats. Male, Sprague Dawley rats were prepared with cerebrocortical EEG and temporalis muscle EMG electrodes. In sham-shocked rats, RX 336-M (6 mg/kg, i.p.) induced behavioral activation, rapid forepaw movements, wet-dog shaking and excessive grooming; this syndrome was associated with EEG activation and EMG spiking. ECS alone produced a generalized seizure followed by postictal EEG slowing and behavioral depression. ECS suppressed the RX 336-M-induced behavioral syndrome and associated EEG and EMG responses. This attenuating action of ECS, presumed to involve the release of endogenous opioids, was antagonized when the rats were pretreated with naloxone (10 mg/kg, s.c.). Our results provide further evidence for the view that endogenous opioids are involved in the pathophysiology of certain postictal phenomena.
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D003061:Codeine / Q000031:analogs & derivatives / Q000494:pharmacology; D004569:Electroencephalography; D004576:Electromyography; D004597:Electroshock; D004723:Endorphins / Q000502:physiology*; D006120:Grooming / Q000187:drug effects; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000928:Antidepressive Agents; D004723:Endorphins; D009292:Narcotic Antagonists; D009270:Naloxone; C006086:RX 336M; D003061:Codeine