Expression of aggressiveness modulates mesencephalic c-fos activation during a social interaction test in Japanese quail (Coturnix japonica)

CALIVA, JORGE MARTIN; MELLEU, FERNANDO FALKENBURGER; MARINO-NETO, JOSE; MARIN, RAUL HECTOR; KEMBRO, JACKELYN MELISSA

BEHAVIOURAL BRAIN RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 367 p. 221 - 229

0166-4328

It is well known that during a social conflict, interactions are dependent on the animal?s propensity to behave aggressively as well as the behavior of the opponent. However, discriminating between these two confounding factors was difficult. Recently, a Social Interaction (SI) test using photocastrated males as non-aggressive stimuli was proposed as a useful tool to evaluate aggressiveness. The avian Intercollicular- Griseum centralis complex (comparable to mammalian periaqueductal gray) has been reported as a crucial node in the descending pathways that organize behavioral and autonomic aspects of defensive responses and aggressiveness. Herein, using the SI test, we evaluated whether mesencephalic areas are activated (expressed c-fos) when photostimulated adult males are confronted with non-responsive (non-aggressive) opponents. Furthermore, we also examined whether the mesencephalic activation is related to male performance during the SI test (i.e., aggressive vs. non-aggressive males), as well as the potential influences of rearing in enriched vs. standard environments. Five mesencephalic areas at two anatomic levels (intermediate and rostral) were studied. Aggressive males showed increased c-fos expression in comparison to their non-aggressive and control counterparts in all areas studied. Non-aggressive males and the test controls showed similar c-fos labeling. In all areas studied, except for the rostral mesencephalicus lateralis pars dorsalis nucleus, rearing condition did not appear to influence c-fos expression. These findings suggest that the mesencephalic activation is involved when males are actively expressing aggressive behaviors. This overall phenomenon is shown regardless of both the environmental stimuli provided during the birds´ rearing and the potentially stressful stimuli during the SI trial.