109 | Early-life stress due to infant maltreatment reshapes stress-response behavior in adult rats

Cognition, Behavior, and Memory

Author: Jazmín Grillo Balboa | Email: jazmin.grillo28@gmail.com

Jazmín Grillo Balboa , Ailén Alba Colapietro , Verónica Cantarelli , Marina Ponzio , María Eugenia Pallarés , Mariela J. Chertoff , Marta Cristina Antonelli

1° Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires. Buenos Aires, Argentina
2° Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba. Córdoba, Argentina
3° IQUIBICEN-DQB, Facultad de Ciencias Exactas y Naturales – Universidad de Buenos Aires – CONICET, Argentina

Early parental care is crucial for the proper development of the cortico-limbic circuits regulating the stress response and emotional well-being. Thus, infant maltreatment may lead to mood-related disorders, impairing individuals’ capacity to deal with stress. Here, we employed the “Scarcity-adversity model” (SAM) in rats −limiting the nesting resources during postnatal days (PND) 8-12− and studied its impact on maternal and adult offspring’s behavior. While the SAM did not affect dam weight gain or fecal corticosterone metabolites, we did find a heightened maternal anxiety-like phenotype in the Elevated plus maze (EPM), shown by a reduced tendency to explore the open arms. Adult offspring underwent a series of anxiogenic tests to assess their reactivity to stress. SAM males showed a decreased locomotor activity in the Open field test; and an earlier, more prolonged time in immobility in the Forced swim test. SAM rats of both sexes exhibited an increased open-arm latency, lower closed-arm latency, and a tendency to decrease their risk-assessment behaviors in the EPM. These results suggest that the SAM protocol induces lasting alterations in the risk-taking behavior, reactivity to novelty and to acute stressors in rodents, with males being more vulnerable than females. Our findings underpin the crucial role of a nurturing early-life environment in fostering both mental and physical well-being later in life, thereby reducing the risk of psychopathology.