Differential effects of cocaine and ketamine on time estimation: implications for neurobiological models of interval timing.


Journal Article

The present experiment examined the effects of cocaine (0.0 and 15 mg/kg, i.p.) and ketamine (0.0, 10.0 and 15 mg/kg, i.p.) on timing behavior using a 12-s differential reinforcement of low rates (DRL) procedure and a 2- vs. 8-s bisection procedure in rats. DRL (time production) and bisection (time perception) procedures are sensitive to effects of dopaminergic drugs and provide an assessment of the accuracy and precision of interval timing as well as the subject's level of impulsivity. When administered to rats trained on either the DRL or the bisection procedure, cocaine shifted the psychophysical functions leftward relative to control conditions. In contrast, ketamine produced no change in the temporal control of behavior on either procedure. These differential effects of cocaine and ketamine are consistent with previous reports suggesting that dopamine levels in the dorsal striatum, but not in prefrontal cortex, ventral striatum or hippocampal regions, are crucial for the regulation of the speed of an internal clock.

Full Text

Cited Authors

  • Cheng, R-K; MacDonald, CJ; Meck, WH

Published Date

  • September 2006

Published In

Volume / Issue

  • 85 / 1

Start / End Page

  • 114 - 122

PubMed ID

  • 16920182

Pubmed Central ID

  • 16920182

Electronic International Standard Serial Number (EISSN)

  • 1873-5177

International Standard Serial Number (ISSN)

  • 0091-3057

Digital Object Identifier (DOI)

  • 10.1016/j.pbb.2006.07.019


  • eng