CCKBR and Anxiety: It is also well-established that CCK-4, of course, targets the cerebral CCK2-receptor and interacts in the provocation of anxiety with other neurotransmitter systems, such as the benzodiazepine/GABA complex, corticotropin-releasing factor, dopamine, noradrenaline, opioids, and serotonin [60,61,62,63,64,65,66,67].