Asymmetry in behavioral responses to cholecystokinin microinjected into rat nucleus accumbens and amygdala

• Published in: Neuropharmacology Vol. 33; no. 8; pp. 995 - 1002
• Main Authors: Belcheva, I., Belcheva, S., Petkov, V.V., Petkov, V.D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.1994; Elsevier
• Subjects: amygdala; Amygdala - anatomy & histology; Amygdala - physiology; Animals; anxiety; Anxiety - psychology; asymmetry; behavior; Behavior, Animal - drug effects; Biological and medical sciences; CCK-8; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; cholecystokinin; Cholecystokinin - administration & dosage; Cholecystokinin - pharmacology; Dose-Response Relationship, Drug; Exploratory Behavior - drug effects; Functional Laterality - drug effects; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; learning; Learning - drug effects; Male; memory; Memory - drug effects; Microinjections; Motor Activity - drug effects; nucleus accumbens; Nucleus Accumbens - anatomy & histology; Nucleus Accumbens - physiology; Rats; Rats, Wistar; Vertebrates: nervous system and sense organs; anxiety; amygdala; memory; cholecystokinin; CCK-8; asymmetry; learning; nucleus accumbens; behavior; Hemispheric specialization; Central nervous system; Basal ganglion; Learning; Nucleus accumbens; Locomotion; Octapeptide; Acquisition process; Animal; Intracerebral administration; Anxiety; Cholecystokinin; Behavior; Amygdaloid nucleus; Brain (vertebrata)
• ISSN: 0028-3908; 1873-7064
• DOI: 10.1016/0028-3908(94)90158-9

The behavioral responses of rats to uni- or bilateral microinjections of the octapeptide cholecystokinin (CCK-8) into the left and/or right or both nucleus accumbens (NA) or amygdalae were studied. There were two main findings of effects of microinjections of CCK-8 into NA. First, bilateral injections of CCK-8 into NA dose-dependently decreased the horizontal activity. The second more important finding was that CCK-8 at a specific dose (0.01 μg) injected into the right NA increased the number of horizontal movements 6-fold as compared to the injection into the left NA. Neither uni- nor bilateral injections of CCK-8 into NA at all doses used induced changes in the vertical movements. CCK-8 injected into left, right or both amigdalae increased locomotion at the lowest dose (0.01 μg), while at the high doses (0.5 and 1.0 μg) it significantly decreased it. The plus-maze test confirmed the anxiogenic effect of CCK-8 (0.01 μg) injected into amigdalae. CCK-8 exerted a favorable effect on learning and memory (shuttle-box) when injected into the left but not into the right amygdala. Injection of CCK-8 (0.01 μg) into left amygdala provoked a 4-fold increase of the number of avoidances as compared to the microinjection into the right amygdala.