Abstract |
We investigated the effects of various serotoninergic drugs and serotonin (5-HT) depletion on physostigmine-induced visible tremor in rats. Physostigmine (0.25-1.5 mg/kg) caused dose-dependent tremor, initiated at 3-5 min (latency decreases as dose increases) and lasted for 30-35 min. Serotonin agonists, 8-hydroxy-2-(di-n-propylamino) tetralin (2.5 mg/kg) and buspirone (5 mg/kg) augmented the tremor response caused by physostigmine. The 5-HT(1)/5-HT(2) receptor antagonist, metergoline (1 mg/kg), and 5-HT(2) blocker, cyproheptadine (10 mg/kg) significantly decreased the duration (40%) as well as intensity (45-50%) of physostigmine- tremor. The 5-HT(2a)/5-HT(2c) antagonist ritanserin (5 mg/kg) significantly reduced the duration (60%) without affecting the intensity of the tremor. In 5-HT depleted rats ( p-chlorophenylalanine; 300 mg/kg, for 3 days), physostigmine failed to produce tremor. Interestingly, in these animals, administration of a non-specific 5-HT agonist, 5-methoxy-N,N-dimethyl tryptamine, caused high intensity tremor. These results suggest that presence of 5-HT at the pre-synaptic terminals is needed for the tremor response by physostigmine and the response is greatly mediated via post-synaptic 5-HT receptors. The overall data indicated a direct involvement of central 5-HT system in the cholinergic tremor induced by physostigmine.
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Authors | S Sarkar, B Thomas, D Muralikrishnan, K P Mohanakumar |
Journal | Behavioural brain research
(Behav Brain Res)
Vol. 109
Issue 2
Pg. 187-93
(May 2000)
ISSN: 0166-4328 [Print] Netherlands |
PMID | 10762688
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Cholinesterase Inhibitors
- Receptors, Serotonin
- Serotonin Agents
- Serotonin Antagonists
- Serotonin Receptor Agonists
- Tetrahydronaphthalenes
- Ritanserin
- Metergoline
- Cyproheptadine
- Serotonin
- Physostigmine
- tetralin
- Buspirone
- N,N-Dimethyltryptamine
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Topics |
- Animals
- Buspirone
(pharmacology)
- Cholinesterase Inhibitors
(adverse effects)
- Cyproheptadine
(pharmacology)
- Metergoline
(pharmacology)
- N,N-Dimethyltryptamine
(pharmacology)
- Physostigmine
(adverse effects)
- Rats
- Rats, Sprague-Dawley
- Receptors, Serotonin
(drug effects, metabolism)
- Ritanserin
(pharmacology)
- Serotonin
(metabolism, physiology)
- Serotonin Agents
(pharmacology)
- Serotonin Antagonists
(pharmacology)
- Serotonin Receptor Agonists
(pharmacology)
- Tetrahydronaphthalenes
(pharmacology)
- Tremor
(chemically induced)
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