Sensitivity to the effects of sedative-hypnotics on motor performance: influence of task difficulty and chronic phenobarbital administration

Citation
Ma. Smith et Ww. Stoops, Sensitivity to the effects of sedative-hypnotics on motor performance: influence of task difficulty and chronic phenobarbital administration, BEHAV PHARM, 12(2), 2001, pp. 125-134
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences & Behavoir
Journal title
BEHAVIOURAL PHARMACOLOGY
ISSN journal
0955-8810 → ACNP
Volume
12
Issue
2
Year of publication
2001
Pages
125 - 134
Database
ISI
SICI code
0955-8810(200104)12:2<125:STTEOS>2.0.ZU;2-N
Abstract
The present investigation examined sensitivity to the effects of various se dative-hypnotics on motor performance in rats treated chronically with phen obarbital, Eight rats were trained to walk on a rotorod treadmill at low (8 r.p.m.) and high (24 r.p.m.) rotational speeds. Prior to the chronic regim en, phenobarbital, pentobarbital, amobarbital, diazepam and clonazepam prod uced dose-dependent impairments in motor performance at both speeds. During chronic treatment with phenobarbital (100 mg/kg/day), tolerance was confer red to the effects of all the drugs examined, as evidenced by rightward shi fts in their dose-effect curves. For all drugs, the magnitude of this toler ance was generally consistent across the two speeds. Following a 6-week was hout period, during which no drugs were administered, dose-effect curves fo r each drug shifted back toward their original (i.e. pre-chronic) positions . Under all conditions, the doses required for each drug to impair motor pe rformance at the low speed were higher than those required to impair motor performance at the high speed. These data suggest that sensitivity to the m otor-impairing effects of sedative-hypnotics is influenced by the difficult y of the behavioral task, but that task difficulty does not modulate the ma ximal extent to which tolerance and cross-tolerance are expressed. (C) 2001 Lippincott Williams & Wilkins.