European Journal of Anatomy

Official Journal of The Spanish Society of Anatomy
Cover Volume 21 - Number 1
Eur J Anat, 21 (1): 49-64 (2017)

The African striped mouse Lemniscomys barbarus as a model for aggression. Brain areas activated by agonistic encounters

Nisrin El Mlili1, Rachid Boutoual2, Ana M. Sanchez-Perez3, Ali Ouarour2, Ibtissam Chakir2, 4, Mohammed Errami2, Francisco E. Olucha-Bordonau3

1Institut Supérieur de Profession Infirmières et Techniques de Santé, Rabat. Morocco, 2Faculté des Sciences, Université Abdelmalek Essaâdi, Tétouan. Morocco, 3Unidad Predepartamental de Medicina, Facultad de Ciencias de la Salud, Universitat Jaume I, Castellón de la Plana 12071 (Spain), 4present address, Faculté de Médecine et depharmacie. Université Sultan Moulay Slimane, Fez Morocco

ABSTRACT During agonistic behavior several brain areas became differentially activated depending on the role the subject is taking. Several areas are mostly activated during the offender role and several others are activated if the subject plays a defensive role. The main goal of this work is to study in detail the anatomic areas involved in agonistic behavior using a novel animal model, the striped mouse Lemniscomys barbarus, a North African diurnal rodent well known by its natural high aggressiveness toward conspecifics. After social encounters, neural activation in brain areas related to agonistic behavior was measured by c-fos immunostaining. The encounters were recorded and behaviors related to the encounter were analyzed. We differentiated between the aggressive behavior (offender) and escape behavior (defender or defeated). Our results showed that conspecific confrontation induced general c-fos activation in both offender and defender in all measured areas in comparison with non-confronted control. Differences in neural activity between offender and defender were observed specifically in the lateral, cortical and medial amygdala, suprachiasmatic nucleus and the nucleus incertus, suggesting a potential role of these areas in displaying different kinds of behavior during conspecific confrontation. We found that, while in the lateral, medial and cortical amygdala defenders express significantly more c-fos than offenders, in the nucleus incertus of the brainstem the differential activation is just the opposite, Additionally, defenders display significantly more freezing than offenders. This work provides data showing that Lemniscomys barbarus is a widely useful model to study the anatomic background supporting agonistic behavior.

Keywords: Amygdala – Social behavior – c-fos – Immediate early genes – Fear – Emotion – Aggression

European Journal of anatomy
ISSN 2340-311X (Online)