Cholecystokinin receptors and memory: a radial maze study

Area of Science:

• Neuroscience
• Pharmacology

Background:

• Cholecystokinin (CCK) receptor agonists and antagonists are known to affect learning and memory.
• Previous studies primarily used avoidance paradigms to investigate these effects.

Purpose of the Study:

• To examine the impact of CCK receptor agonists and antagonists on appetitively motivated learning and spatial working memory.
• To explore the effects of these compounds in a radial maze task.

Main Methods:

• Rats were administered CCK receptor agonists (caerulein, CCK-4) and antagonists (proglumide, devazepide) in different experimental setups.
• Experiment 1 involved post-training drug administration, followed by drug-free testing.
• Experiment 2 involved pre-test drug administration in well-trained animals.

Main Results:

• In Experiment 1, acute post-training administration of caerulein showed a minor initial deficit in food acquisition, with no lasting effects.
• Proglumide had no effect in Experiment 1.
• In Experiment 2, none of the tested CCK receptor agonists or antagonists, including the reference drug scopolamine, reliably affected spatial working memory in the radial maze.

Conclusions:

• CCK receptor agonists and antagonists, at the doses and conditions tested, do not appear to significantly influence learning in an appetitively motivated task or spatial working memory.
• Findings suggest that the role of CCK receptors in learning and memory may be context-dependent or require different experimental paradigms.