Transcallosally evoked potentials and the EEG in the decerebrate dog: actions of tryptaminergic, dopaminergic and adrenergic agonists.
W B Pickworth, L G Sharpe, W R Martin
Electroencephalography and Clinical Neurophysiology June 1977 DOI: 10.1016/0013-4694(77)90234-6 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Animal experiment (decerebrate dog preparation) Peer reviewed |
|---|---|
| Population | Midpontine decerebrate dogs immobilized with gallamine |
| Interventions | LSD DMT Tryptamine Mescaline Methoxamine Apomorphine |
| Dose | LSD 30 microng/kg; DMT 1 mg/kg; tryptamine 10 and 20 mg/kg; mescaline 6 mg/kg; methoxamine 0.88 mg/kg; apomorphine 5 mg/kg |
| Duration | Effect of LSD persisted at least 80 min after administration |
| Measures | Transcallosally evoked potential (TEP), EEG (analyzed by inspection and amplitude integration/electrogenesis) |
| Key findings | LSD (30 µg/kg) significantly depressed the transcallosally evoked potential for at least 80 minutes, whereas DMT (1 mg/kg) significantly and reversibly increased its amplitude. Both reduced EEG alpha activity and enhanced low-frequency wave amplitude. Tryptamine, mescaline, methoxamine, and apomorphine had no significant effect. The authors suggest TEP depression is unrelated to spinal reflex facilitation in dogs or hallucinogenic activity in humans. |
Abstract
The midpontine decerebrate dog, immobilized with gallamine, was used to determine the changes in the transcallosally evoked potential (TEP) produced by intravenous infusions of various drugs. A total of 50 TEPs, recorded from the g. ectolateralis, was computer analyzed before, during and after administration of the drugs. Changes in the TEP were also correlated with changes in the EEG recorded from the g. ectolateralis. The EEG was analyzed by inspection and amplitude integration (electrogenesis). LSD (30 microng/kg) significantly depressed the TEP, and the effect persisted for at least 80 min. DMT (1 mg/kg) caused a significant and reversible increase in the amplitude of the TEP. LSD and DMT reduced the alpha activity of the EEG and enhanced the amplitude of the low-frequency waves. DMT produced a significant and LSD a marginal increase in electrogenesis. Tryptamine (10 and 20 mg/kg), mescaline (6 mg/kg), methoxamine (0.88 mg/kg) and apomorphine (5 mg/kg) had no significant effect on the TEP or EEG. These results suggest that depression of the TEP is not related to spinal reflex facilitation in the dog or hallucinogenic activity in man.
Citations in the library
Cites 5
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- A Pharmacologic Analysis of the Functions of the Spontaneous Electrical Activity of the Cerebral Cortex The Journal of Nervous and Mental Disease September 1, 1954
- Effect of mescaline on single cortical neurones British Journal of Pharmacology December 1, 1971
- Effects of infused tryptamine in man Psychopharmacologia September 1, 1970
- Actions of certain amines on cerebral cortical neurones. British Journal of Pharmacology and Chemotherapy June 1, 1963