Modulation of memory processing by cholecystokinin: dependence on the vagus nerve

Area of Science:

• Neuroscience
• Gastroenterology
• Behavioral Science

Background:

• Feeding immediately after aversive training enhances memory retention in mice.
• Cholecystokinin-octapeptide (CCK-8), a gastrointestinal hormone, is released during feeding.
• CCK-8 administered peripherally enhances memory retention.

Purpose of the Study:

• To investigate the role of cholecystokinin-octapeptide (CCK-8) in memory retention.
• To determine if CCK-8 mediates the memory-enhancing effects of feeding.
• To explore the neural pathways involved in CCK-8's memory effects.

Main Methods:

• Administering CCK-8 intraperitoneally to mice.
• Performing vagotomy (cutting the vagus nerve) in mice.
• Assessing memory retention after training and CCK-8 administration.

Main Results:

• Peripheral administration of CCK-8 enhanced memory retention.
• The memory-enhancing effect of CCK-8 was abolished by vagotomy.
• These findings suggest CCK-8 activates ascending vagal nerve fibers.

Conclusions:

• CCK-8, a peripherally acting peptide, may mediate the memory-enhancing effects of feeding.
• The vagus nerve plays a crucial role in CCK-8's influence on memory.
• CCK-8 represents a potential therapeutic target for memory enhancement.