P.1.029 DNase activity of immunoglobulins G in schizophrenia patients with tardive dyskinesia

anhedonia, which could affect reward seeking behaviour. We found that 17 days of caloric restriction, which increased plasma acyl-ghrelin concentrations (p< 0.05), significantly reduced immobility time in the forced swim test (p< 0.005), which was unaffected by IP administration of the GHSR1a receptor antagonist (D-lys3)-GHRP-6 at 66 nmol/10 g. In addition, plasma corticosterone concentrations were increased in calorie-restricted animals 30 minutes after the forced swim test (p< 0.005), which was likewise unaffected by GHSR1a antagonism. Together, this indicates that GHSR1a signalling is involved in sucrose reward seeking under both stressed and non-stressed conditions. Whereas under unstressed conditions GHSR1a receptor signalling in the arcuate nucleus is needed to establish a baseline reward seeking behaviour, this signalling maintains reward seeking behaviour after chronic social defeat stress. Since ghrelin’s central role in appetite regulation, it is important to consider how GHSR1a signalling and appetite are involved in stress-related reward seeking. Hence, we showed that acute GHSR1a receptor antagonism does not affect appetite-induced antidepressive-like behaviour or corticosterone release, and future experiments will therefore be aimed to tease apart the complex relationship between GHSR1a signalling, appetite, stress and reward seeking.