OLFACTORY-BULB NOREPINEPHRINE DEPLETION ABOLISHES VASOPRESSIN AND OXYTOCIN PRESERVATION OF SOCIAL RECOGNITION RESPONSES IN RATS

Male rats were implanted bilaterally with cannulae directed at the olf actory bulbs and infused with either vehicle or 6-OHDA to selectively deplete norepinephrine concentrations at this site. At 5-7 days follow ing this treatment, these animals received a bilateral infusion of eit her arginine vasopressin (AVP) or oxytocin (OXT) through these same gu ide cannulae and were then tested for their capacity to maintain socia l recognition responses. Neither infusion of AVP nor OXT were able to preserve recognition responses in the animals treated with 6-OHDA. In contrast, comparably tested animals who received a vehicle infusion sh owed clear recognition responses following either the AVP or OXT infus ion. These results suggest that this capacity for these neuropeptides to preserve social recognition responses is mediated through the norep inephrine system of the olfactory bulb. (C) 1998 Elsevier Science Irel and Ltd. All rights reserved.