Abstract
Previous investigations have suggested a neuroleptic-like action of cholecystokinin-octapeptide (CCK8) on conditioned-avoidance behavior. This study was initiated to test tolerance to this effect. Rats were trained to avoid electric shock in a shuttle box under a free-operant (Sidman) avoidance paradigm. Each shuttle response postponed a 0.2 sec, 1 mA shock for 20 sec. If the rat failed to respond, shock was delivered every 5 sec until a response occurred. After avoidance training, half of the rats received two daily injections of CCK8 (0.320 mg/kg, IP) and half received saline for 7 days. Rats were then tested on the Sidman avoidance 1 min after receiving CCK8 (0.640 mg/kg, IP) or saline. CCK8 depressed avoidance responding if rats received saline for 7 days prior to the test. Rats pretreated with CCK8 for 7 days were not significantly affected by CCK8 during the avoidance test. Thus, repeated injections of CCK8 result in tolerance to its anti-avoidance properties.
Original language | English (US) |
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Pages (from-to) | 67-70 |
Number of pages | 4 |
Journal | Peptides |
Volume | 4 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 1983 |
Keywords
- Avoidance
- Cholecystokinin-octapeptide
- Peptide
- Tolerance
ASJC Scopus subject areas
- Biochemistry
- Physiology
- Endocrinology
- Cellular and Molecular Neuroscience