Effects of cycloleucine in the nucleus accumbens septi on the elevated plus maze test in rats

Abstract Introduction: In recent years, an important number of studies have emphasized the psychopharmacological actions of cycloleucine (1-aminocyclopentanecarboxylic acid) acting on the NR1 subunit (glycine allosteric site) of NMDA (Nmethyl-D-aspartic acid) receptor. We studied the effects of its injection in an anxiety test. Methods: The elevated plus maze test was used. Male rats bilaterally cannulated into the nucleus accumbens septi (NAS) were employed. Rats were divided into 5 groups that received either 1 µL injections of saline or cycloleucine (0.5, 1, 2, or 4 µg) 15 min before testing. Results: Time spent in the open arm was significantly increased by cycloleucine treatment with all doses (1 and 2 µg, p < 0.05; 0.5 and 4 µg, p < 0.01), like number of extreme arrivals (0.5 and 1 µg, p < 0.05; 2 µg, p < 0.01; and 4 µg, p < 0.001). Open arm entries were increased by the highest dose only (4 µg, p < 0.01). Discussion/Conclusion: Present results show no difference between all doses in the time spent in the open arm, suggesting an indirect, noncompetitive action of the drug. The increase in extreme arrivals and open arm entries suggests a dose influence in these parameters. We conclude that cycloleucine influence on the NMDA receptors within NAS leads to anxiolytic-like effects and behavioral disinhibition, which once more confirms the involvement of NAS in anxiety processing.Fil: Gargiulo, Augusto P.I.. Universidad Nacional de Cuyo; ArgentinaFil: Acuña, Andres. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Gargiulo, Mercedes Maria Lucrecia. Universidad Nacional de Cuyo; ArgentinaFil: Gargiulo, Ángel José Martín. Universidad Nacional de Cuyo; ArgentinaFil: Gargiulo, Marcos C. J.. Universidad Nacional de Cuyo; ArgentinaFil: Baiardi, Gustavo Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Mora, Sergio. Universidad de Chile; ChileFil: Lafuente, José Vicente. Universidad del País Vasco; EspañaFil: Romanowicz, Esteban Alejandro. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Landa, Adriana. Universidad Nacional de Cuyo; ArgentinaFil: Guevara, Manuel Alejandro. Universidad Nacional de Cuyo; ArgentinaFil: Gargiulo, Pascual Angel. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin