Cohen Hagit, Matar Michael A, Buriakovsky Igor, Zeev Kaplan, Kotler Moshe, Bourin Michel
Ministry of Health Mental Health Center, Faculty of Health Sciences, Anxiety and Stress Research Unit, Ben Gurion University of the Negev, Beer-Sheva, Israel.
Neuropeptides. 2002 Oct;36(5):341-52. doi: 10.1016/s0143-4179(02)00088-4.
Cholecystokinin and its analogs generate anxiety in humans and measurable anxiety-like behaviors in rats. Cholecystokinin receptor blockers have been reported to have variable effects in the treatment of anxiety disorders. We demonstrated that intracerebroventricular administration of Cholecystokinin-antisense oligodeoxynucleotides (ASODN) for 3 days significantly diminished anxiety-like behavior in rats.
This study was designed to examine the effects of peripheral (intraperitoneal) administration of Cholecystokinin-ASODN on anxiety-like and learning behaviors in rats, in general and in a pre-experiment stress paradigm.
In the first study Cholecystokinin-ASODN was injected intraperitoneally to rats five times at 24-h intervals. Control groups received injections of either a scrambled oligodeoxynucleotide (ScrODN) or vehicle. On the sixth day, the rats were assessed in the elevated plus-maze paradigm and in the Morris water maze. In the second study, rats were pre-exposed to a cat for 10 min as a model for psychological stress, and then treated with intraperitoneal Cholecystokinin-ASODN and tested in both paradigms.
The results show that for intact rats, intraperitoneal Cholecystokinin-ASODN significantly increased anxiety-like behavior and impaired retention performance in the Morris water maze, compared to both control groups. In stressed rats, Cholecystokinin-ASODN reduced anxiety-like behaviors in the plus-maze and improved performance in the water maze compared with controls.
These results indicate that the anxiolytic effect of intraperitoneal Cholecystokinin-ASODN may be dependent on the baseline endogenous level of stress (i.e., on the Cholecystokinin levels). Basal endogenous levels of Cholecystokinin, as well as exogenous dosage of Cholecystokinin agonists and/or anxiolytic agents, appear to play an important role in the expression and/or control of anxiety-related behaviors in rats.
