TY - JOUR
T1 - Effects of serotoninergic drugs on tremor induced by physostigmine in rats
AU - Sarkar, S.
AU - Thomas, B.
AU - Muralikrishnan, D.
AU - Mohanakumar, K. P.
N1 - Funding Information:
DST, Government of India, financed the research work. BT received fellowship from the DST grant. DM is a recipient of Senior Research Fellowship from CSIR, Goverment of India. SS is an intern at Calcutta Medical College, and was a summer student in the laboratory. Thanks are due to S.C. Sharma for technical assistance and S.K. Sahoo for drawing figures.
PY - 2000/5
Y1 - 2000/5
N2 - 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-HT1/5-HT2 receptor antagonist, metergoline (1 mg/kg), and 5-HT2 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. Copyright (C) 2000 Elsevier Science B.V.
AB - 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-HT1/5-HT2 receptor antagonist, metergoline (1 mg/kg), and 5-HT2 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. Copyright (C) 2000 Elsevier Science B.V.
KW - 5-HT involvement
KW - Cholinergic tremor
KW - Physostigmine
KW - Serotonin depletion
KW - Serotonin receptors
KW - Tremor
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U2 - 10.1016/S0166-4328(99)00171-0
DO - 10.1016/S0166-4328(99)00171-0
M3 - Article
C2 - 10762688
AN - SCOPUS:0034070574
SN - 0166-4328
VL - 109
SP - 187
EP - 193
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 2
ER -