The Role Of Neuropeptide S In Novel Object Recognition Memory And The Underlying Mechanisms

Neuropeptide S(NPS),the endogenous ligand of NPSR,was identified in 2002.The NPS/NPSR system has been reported to modulate multiple physiological and pathological functions including arousal,anxiolytic-like effects and drug addiction.The predominant distribution of NPSR in brain tissues associated with learning and memory indicating that NPS might play a crucial role in regulating learning and memory.It has been reported that the NPS system plays an important role in spatial memory and conditioned fear memory.Based on the distribution of NPSR and reported functions of NPS/NPSR system,we will investigate the role of NPS in novel object recognition memory and the underlying mechanisms.In this article,we investigated the role of NPS in object recognition memory consolidation by intracerebroventricular(i.c.v.)injection and intra-BLA infusions respectively,using a mouse novel object recognition tasks.Our data showed that in novel object recognition tasks,NPS facilitated object recognition memory formation in consolidation phase as well as prolonged memory retention.And the improvement of memory induced by NPS could be blocked by the selective NPSR antagonist SHA68 and P-adrenoceptor antagonist propranolol.In addition,intra-BLA infusions of NPS improved memory for objects,which could be impaired by co-administration of propranolol.Taken together,our results suggest that NPS improves object recognition memory through the activation of its endogenous receptor NPSR and requires noradrenergic activity.In addition,we determined whether NPS could mitigate memory impairment in mice induced by selective N-methyl-D-aspartate receptor antagonist MK801,muscarinic cholinergic receptor antagonist scopolamine or Aβ1-42.Our data proved that in novel object recognition task,i.c.v.injection of NPS reversed memory disruption induced by MK801,scopolamine or Aβ1-42In summary,our results indicate that NPS facilitates memory formation as well as prolongs the retention of memory through activation of the NPSR,and interacts with the BLA noradrenergic system.Besides,NPS mitigates amnesia induced by MK801,scopolamine or Aβ1-42,indicating that NPS/NPSR system might be a new target for enhancing memory and treating amnesia.