EFFECTS OF SINGLE INJECTION OF NALOXONE AND DAMGO WITHIN NUCLEUS ACCUMBENS SEPTI IN THE PLUS MAZE TEST IN RATS

GARGIULO PA ; ELIAS PA; RODRIGUEZ V; OKASOVA A; LANDA AI; BAIARDI GC; MULET D; SOAJE M; LAFUENTE JV; GALIANA G; MORSUCCI C

ACTA POLONIAE PHARMACEUTICA

POLSKIEGO TOWARZYSTWA FARMACEUTYCZNEGO

Año: 2018 vol. 75 p. 205 - 210

0001-6837

Abstract: Nucleus accumbens septi (NAS) is studied because its relations with cognition and anxiety. Its pharmacologicalmanipulation is widely used in experimental psychopathology to reproduce psychotic signs andsymptoms in animal models. In the present study, the effect of the injection of an agonist and a μ-receptorantagonist in this structure is assessed. Holtzman strain male rats (240-290 g) were cannulated bilaterally inNAS. One week after the injection they were subjected to an anxiety test, prior saline injection (controls),DAMGO ([D-Ala2, N-MePhe4, Gly-ol]-encephalin, opioid agonist) or naloxone (opioid antagonist). We evaluatedthe set of parameters classically considered in our laboratory (open arm time, time per entry, open armentries, closed arm entries, open/closed arm quotient, open and closed arm ends arrivals, rearing, fecal bowlsand grooming behaviors. There was only a significant increase in the length of stay in the open arm with theinjection of DAMGO (0.2 μg/1 μL, p < 0.05) and a significant increase in grooming behaviors with naloxone(1 μg/1 μL, p < 0.001), compared with saline controls (1 μL). We conclude that the receptor stimulation in NASgenerates effects compatible with anxiolysis, and blocking of such receptor in said structure results in anincrease in grooming behaviors.