Chronic aortic denervation decreases anxiety and impairs social memory in rats.

Abstract Aims The present study investigates anxiety-like behaviour and social cognitive performance in rats with chronic aortic denervation. Main methods The aortic depressor nerve was bilaterally transected in Wistar rats, causing an almost complete disruption of baroreceptors. Bilateral aortic denervated (bAD), sham-operated (SHAM), and intact (CTRL) rats performed an elevated plus-maze test and an olfactory social memory test, one and three months after operation. Blood pressure and heart rate were monitored in all animals. Key findings Systolic blood pressure, blood pressure lability and heart rate were elevated in bAD rats compared to SHAM and CTRL rats. In the elevated plus-maze test, bAD rats spent clearly more time in investigating open arms and performed more open arm entries than SHAM and CTRL rats during both testing sessions. The olfactory social memory test revealed that acquisition time during first contact with a juvenile rat did not differ between the groups of rats. The recognition time spent by SHAM and CTRL group of rats was distinctly decreased in comparison to the acquisition time, an indication of social memory. bAD rats investigated the juvenile rat during the second contact to a similar extent than during the first contact, both one and three months after denervation. Significance These results suggest that bilateral aortic denervation induces chronic neurogenic hypertension and elevated blood pressure lability, decreases anxiety-like behaviour and deteriorates social memory in rats while acquiring of social information is not affected.