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The effects of anticholinergic drugs on delayed time discrimination performance in rats.
Journal article

The effects of anticholinergic drugs on delayed time discrimination performance in rats.

  • Berz S Laboratory of Behavioral Biology, Federal Institute of Technology (ETH), Zürich, Switzerland.
  • Bättig K
  • Welzl H
  • 1992-03-01
Published in:
  • Physiology & behavior. - 1992
Animals
Brain
Cholinergic Fibers
Conditioning, Operant
Discrimination Learning
Dose-Response Relationship, Drug
Male
Mecamylamine
Mental Recall
Parasympatholytics
Rats
Rats, Inbred Strains
Reaction Time
Receptors, Muscarinic
Receptors, Nicotinic
Scopolamine
Time Perception
English To investigate the effects of the muscarinic antagonist scopolamine and the nicotinic antagonist mecamylamine on time discrimination and short-term memory, rats were trained on a delayed conditional time discrimination task until performance stabilized. In a two-lever operant chamber, pressing one lever was correct after the presentation of a stimulus light for 2 seconds (SD short); and pressing the other lever was correct after presentation of a stimulus light for 8 seconds (SD long). Scopolamine (0.06 mg, 0.25 mg, and 1.0 mg/kg) attenuated performance in a dose-dependent manner. Furthermore, the drug decreased nose-pokes (an activity necessary to trigger the presentation of the discriminative stimuli and the presentation of the response levers), and increased response delay (time from opportunity to lever press to actual lever press). Performance attenuating effects of mecamylamine in the time discrimination task did not appear unless high doses (8 mg/kg) of the drug were given. With increasing delays between 0 and 8 seconds, animals injected with saline developed a bias towards reporting the occurrence of the SD long, independent of the actual stimulus presented. A reversal of this bias was seen in animals injected with scopolamine; they more often reported the occurrence of the SD short. Our results support a role for muscarinic receptors in discrimination learning, attention, and time estimation.
Language
  • English
Open access status
closed
Identifiers
Persistent URL
https://sonar.ch/global/documents/123723
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