Ketamine "unlocks" the reduced clock-speed effects of cocaine following extended training: evidence for dopamine--glutamate interactions in timing and time perception.


Journal Article

The present study examined the clock-speed modulating effects of acute cocaine administration in groups of male rats that received different amounts of baseline training on a 36-s peak-interval procedure prior to initial drug injection. After injection of cocaine (10, 15, or 20mg/kg, ip), rats that had received a minimal amount of training (e.g., or=180 sessions) prior to cocaine (15 mg/kg, ip) administration did not produce this "classic" curve-shift effect, but instead displayed a general disruption of temporal control following drug administration. Importantly, when co-administered with a behaviorally ineffective dose of ketamine (10mg/kg, ip) the ability of cocaine to modulate clock speed in rats receiving extended training was restored. A glutamate "lock/unlock" hypothesis is used to explain the observed dopamine-glutamate interactions as a function of timing behaviors becoming learned habits.

Full Text

Cited Authors

  • Cheng, R-K; Ali, YM; Meck, WH

Published Date

  • September 2007

Published In

Volume / Issue

  • 88 / 2

Start / End Page

  • 149 - 159

PubMed ID

  • 17513138

Pubmed Central ID

  • 17513138

Electronic International Standard Serial Number (EISSN)

  • 1095-9564

International Standard Serial Number (ISSN)

  • 1074-7427

Digital Object Identifier (DOI)

  • 10.1016/j.nlm.2007.04.005


  • eng