• Reduce text

    Reduce text
  • Restore text size

    Restore text size
  • Increase the text

    Increase the text
  • Print

    Print

Emotional behaviours and brain of sheep: to be or not to be a prey

When comparing across species, the periaqueductal gray (PAG)  connections of sheep were noticeably more like those previously described in other social species, rabbits and squirrel monkeys, than those in territorial species, rats or cats.

. © INRA
Updated on 02/06/2019
Published on 02/05/2019

Background:
The periaqueductal gray (PAG) is a mesencephalic brain structure organised in subdivisions with specific anatomical connections with the rest of the brain. These connections support the different PAG functions and especially its role in emotion. Mainly described in territorial and predatory mammals, examination of the PAG connections suggests an opposite role of the ventral and the dorsal/lateral PAG in passive and active coping style, respectively.

Material and Methods:
In mammals, the organisation of PAG connections may reflect the coping style of each species. Based on this hypothesis, we investigated the anatomical connections of the PAG in sheep, a gregarious and prey species. Since emotional responses expressed by sheep are typical of active coping style, we focused our interest on the dorsal and lateral parts of the PAG. After injection of fluorogold and fluororuby, the most numerous connections occurred with the anterior cingulate gyrus, the anterior hypothalamic region, the ventromedial hypothalamic nucleus and the PAG itself.

Results:
Our observations show that the sheep PAG belongs to the neuronal circuit of emotion and has specific parts as in other mammals. However, unlike other mammals, we observed very few connections between PAG and either the thalamic or the amygdalar nuclei. Interestingly, when comparing across species, the PAG connections of sheep were noticeably more like those previously described in other social species, rabbits and squirrel monkeys, than those in territorial species, rats or cats.

Contact(s)
Scientific contact(s):

Associated Division(s):
Animal Physiology and Livestock Systems
Associated Centre(s):
Val de Loire

References

Publications based on this work:

1- Menant O., Prima M.-C., Morisse M., Cornilleau F., Moussu Chr., Gautier A., Blanchon H., Meurisse M., Delagrange P., Tillet Y., Chaillou E. (2018) The periaqueductal gray (PAG) connections in sheep: a framework of the anatomical circuit of emotion. Brain Stuctrure and Function 223(7), 3297-3316 DOI : 10.1007/s00429-018-1689-y

2- Zelena, D., Menant, O., Andersson, F., & Chaillou, E. (2018). Periaqueductal gray and emotions: the complexity of the problem and the light at the end of the tunnel, the magnetic resonance imaging. 52(4), 222-238. doi: https://doi.org/10.2478/enr-2018-0027

3- Menant, O., Destrez, A., Deiss, V., Boissy, A., Delagrange, P., Calandreau, L., Chaillou, E. (2016). Régulation des émotions chez l'animal d'élevage : focus sur les acteurs neurobiologiques. INRA Productions Animales, 29 (4), 241-245.

4- Menant, O., Andersson, F., Zelena, D., Chaillou, E. (2016). The benefits of magnetic resonance imaging methods to extend the knowledge of the anatomical organisation of the periaqueductal gray in mammals. Journal of Chemical Neuroanatomy, 77, 110-120. DOI : 10.1016/j.jchemneu.2016.06.003

Other publications cited:

Boissy A., Arnould C., Chaillou E., Colson V., Désiré L., Duvaux-Ponter C., Greiveldinger L., Leterrier C., Richard S., Roussel S., Saint-Dizier H., Salaün M.C., Valance D., 2007. Emotions et cognition : stratégie pour répondre à la question de la sensibilité des animaux. In : Numéro spécial, Bien-être animal. INRA Prod. Anim., 20, 17-22.

Cook C.J., 2001. Measuring of extracellular cortisol and corticotropin-releasing hormone in the amygdala using immunosensor coupled microdialysis. J. Neurosci. Methods, 110, 95-101.

Dantzer R., 2002. Les émotions, Que sais-je ? Presses universitaires de France.

Guesdon, V., Meurisse, M., Chesneau, D., Picard, S., Lévy, F., Chaillou, E. (2015). Behavioral and endocrine evaluation of the stressfulness of single-pen housing compared to group-housing and social isolation conditions. Physiology and Behavior, 147, 63-70. DOI : 10.1016/j.physbeh.2015.04.013

Menant, O., Destrez, A., Deiss, V., Boissy, A., Delagrange, P., Calandreau, L., Chaillou, E. (2016). Régulation des émotions chez l'animal d'élevage : focus sur les acteurs neurobiologiques. INRA Productions Animales, 29 (4), 241-245.