Systemic dizocilpine (MK-801) facilitates performance in opposition to response bias
Regan G Wisnewski1, Johan Lauwereyns
1School of Psychology, Victoria University of Wellington, Wellington, New Zealand. jan.lauwereyns@vuw.ac.nz.
Behavioral and Brain Functions : BBF
|September 21, 2007
Summary
The NMDA-receptor antagonist MK-801 improved reaction time in rats performing tasks with small rewards. This suggests MK-801 facilitates performance under conditions of limited reinforcement, offering insights into behavioral control.
Area of Science:
- Neuroscience
- Behavioral Pharmacology
Background:
- Dopamine is crucial for reward-oriented behavior.
- The effects of NMDA-receptor antagonists on task performance under varying reward conditions are not well understood.
Purpose of the Study:
- To investigate the impact of dizocilpine (MK-801), an NMDA-receptor antagonist, on reaction time in rats under asymmetric reward schedules.
- To explore the psychopharmacology of task performance influenced by small versus large rewards.
Main Methods:
- Rats performed a nose-poke task with differential reward magnitudes (large vs. small).
- Dizocilpine (MK-801) was administered systemically at various dosages.
- Reaction times (RT) were measured to assess task performance.
Main Results:
- Reaction times were faster for large rewards than small rewards, confirming previous findings.
- A low dose of MK-801 (0.04 mg/kg) significantly decreased RT in small-reward trials, indicating improved performance.
- Higher MK-801 doses impaired task performance in most rats.
Conclusions:
- Systemic administration of low-dose MK-801 facilitates performance in tasks with small rewards.
- This facilitation may involve mechanisms counteracting response bias.
- The study presents a valuable paradigm for investigating voluntary control over actions under reward-based motivation.
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