0231–424X/$ 20.00 © 2013 Akadémiai Kiadó, Budapest Acta Physiologica Hungarica, Volume 100 (4), pp. 361–377 (2013) DOI: 10.1556/APhysiol.100.2013.4.1 The role of cholecystokinin in the induction of aggressive behavior: A focus on the available experimental data (Review) E Katsouni 1,2 , A Zarros 2,3 , N Skandali 2,4 , S Tsakiris 2 , D Lappas 5 1 Worcester College, University of Oxford, Oxford, UK 2 Laboratory of Physiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece 3 College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK 4 Institute of Neurology, University College London (UCL), London, UK 5 Laboratory of Anatomy, Medical School, National and Kapodistrian University of Athens, Athens, Greece Received: June 21, 2013 Accepted after revision: July 23, 2013 Cholecystokinin (CCK) is a neuropeptide that is (among others) reportedly involved in the pathophysiology of psychiatric disorders. The excitatory role of CCK in negative affective emotions as well as in aversive reactions, antisocial behaviors and memories, has been indicated by numerous electrophysiological, neurochemical and behavioral methodologies on both animal models for anxiety and human studies. The current review article summarizes the existing experimental evidence with regards to the role of CCK in the induction of aggressive behavior, and: (a) synopsizes the anatomical circuits through which it could potentially mediate all types of aggressive behavior, as well as (b) highlights the potential use of these experimental evidence in the current research quest for the clinical treatment of mood and anxiety disorders. Keywords: cholecystokinin, CCK receptors, aggressive behavior, neuroanatomical circuits, dopamine, serotonin, neuromodulators, mood, anxiety disorders, stress, experimental data, nucleus accumbens Aggression is a hostile, injurious or destructive behavior towards a stimulus (91). The classification of this behavior is complicated and can be manifested through a variety of forms including predatory attack and defensive rage in animals (67, 89). These forms of aggression are consistent with the bimodal theory of human violence, suggesting that it can become either predatory or affective (62). Seroczynski et al. (82) have provided evidence on the heritability of impulsive aggression, a form of aggression in which the individual manifests this behavior spontaneously (without having planned it), accompanied by high autonomic arousal. This kind of aggression is common in those suffering from the intermittent explosive disorder (91). In addition, Coccaro et al. (22) have also provided support for the heritability of impulsive aggression and its correlation with irritability. On the contrary, planned aggression (usually called as “premeditated”, “instrumental” or “proactive”) does not involve the perception of an immediate threat and is under the regulation of a different neural circuit that does not involve autonomic arousal (91). Corresponding author: Dr Stylianos Tsakiris, PhD, Associate Professor Laboratory of Physiology, Medical School, National and Kapodistrian University of Athens PO Box 65257, GR-15401, Athens, Greece Phone: +30-210-7462662; Fax: +30-210-7462571; E-mail: stsakir@med.uoa.gr