Program & Abstract Book - EPFL Latsis Symposium 2009

EPFL Latsis Symposium 2009: Understanding Violence
P-14
68
February 11-13 2009
co m m u n a l n e s t i n g , a n e a r l y s o c i a l
e n r i c h m e n t , s h a p e s s o c i a l b e h a v i o r a n D
c o p i n g r e s p o n s e t o s o c i a l s t r e s s in a D u l t
m o u s e
D’Andrea, Ivana 1 ; Cirulli, Francesca 1 ; Branchi, Igor 1 ; Alleva,
Enrico 1
1 Section of Behavioural Neurosciences, Department of Cell Biology
and Neuroscience, Istituto Superiore di Sanità, Rome, Italy.
Early experiences produce persistent changes in behavior and brain function.
Being reared in a Communal Nest (CN), consisting of a single nest
where three mothers keep their pups together and share care-giving behavior
from birth to weaning, provides an highly stimulating social environment
to the developing pup. CN characterizes the natural ecological
niche of the mouse species and represents a form of early social enrichment.
In the CN, both mother-offspring and peer-to-peer interactions are
markedly increased. At adulthood, CN mice show higher propensity to
interact socially with conspecifics and more elaborate social competencies
compared to mice reared in standard laboratory conditions (SN). In
particular, CN mice play the role of either the dominant or the subordinate
starting from the first agonistic encounter, while SN mice need five social
encounters to fully show their social role. Furthermore, CN mice display
high levels of aggressive behavior only when appropriate in an ecoethological
perspective, i.e. when they have to set up or defend their own
territory. With regard to emotional behavior and hypothalamic-pituitaryadrenal
(HPA) axis activation, CN mice are less vulnerable to anhedonia
following psychosocial stress and display a reduced activation of the HPA
axis after acute or prolonged exposure to social challenge. The present
findings show that being reared in a CN plays a crucial role in structuring
adult social competencies in the mouse. Overall, the social environment to
which an organism is exposed during critical developmental periods, exerts
a major effects in shaping social behavior at adulthood. Supported by
EU, project INTELLIMAZE contract n 037965.