Chlordiazepoxide specifically impairs nonspatial reference memory in the cued radial arm maze in rats

Anxiolytic benzodiazepines, at low doses, reportedly impair the radial arm maze with nonspatial visual/tactile but not spatial cues. We replicated the former result controlling for changes in drug state and cue effectiveness. Rats learned an eight-arm radial maze with reward in only four arms. The r eward varied in spatial position from trial to trial but was always cued by a piece of sandpaper at the entry to the arm. Chlordiazepoxide (5 mg/kg, i p) impaired acquisition. Rats that switched from saline during acquisition to chlordiazepoxide showed an impairment of performance that only lasted fo r 1 day. Removal of the cues reduced the performance of controls and switch ed rats to the level of the rats that received chlordiazepoxide during acqu isition but did not affect the latter. These data suggest that chlordiazepo xide does indeed impair nonspatial reference memory in the radial arm maze while leaving working memory, and, possibly, spatial reference memory, inta ct but that the previous report of this effect was the result of a change i n drug state rather than of the drug itself. (C) 2001 Elsevier Science Inc. All rights reserved.