Drugs for Parkinson's disease reduce tremor induced by physostigmine

Abstract

The effects of anticholinergic and dopaminergic drugs used for Parkinson's disease were studied on the tremor induced by physostigmine (0.3-3.0 mg/kg) in rats. For the measurement of tremor a new electronic device was employed. Atropine (0.3-1.2 mg/kg) and biperiden (0.01-1.0 mg/kg) reduced the physostigmine-induced tremor in a dose-related manner and could abolish it. Biperiden was less potent than atropine. Methylatropine in a dose of 1.2 mg/kg slightly inhibited the tremor. Amantadine (0.3-3.0 mg/kg) reduced the tremor but only to a certain degree. Bromocriptine (0.1-10.0 mg/kg) reduced it in a manner that was not dose-related. Pimozide potentiated the tremor in the dose of 0.2 mg/kg but not in larger doses. At the onset of the tremor, a small decrease in rectal temperature occurred. The hypothermia lasted significantly longer than the tremor. Neither the anticholinergic nor the dopaminergic anti-Parkinson drugs altered the hypothermic effect of physostigmine. The results show that those anti-Parkinson drugs, which act by increasing the dopaminergic activity can counteract the tremor induced by physostigmine. However, these drugs are clearly less active than th anticholinergic anti-Parkinson drugs.

Stimulus conditioned to foot-shock stress reinstates alcohol-seeking behavior in an animal model of relapse

“…In a subset of rats that were not included in the subsequent reinstatement tests, withdrawal signs (including the ventromedial distal limb reflexion response, tail stiffness and abnormal body posture) were rated using a scale modified from Gothoni et al (1983) 8-12 h after termination of ethanol vapor inhalation, as previously described (Macey et al 1996). A subjective 0-to 2-point scale was used for each of these signs, with 0 representing undetectable, 1 representing moderate, and 2 representing severe withdrawal sign.…”