Influenza infection during pregnancy causes behavioral disturbancies in young mice

GALEANO, PABLO; LANDREAU, F; TOUS, M; PONTORIERO, A; SAVY, V; AMOROSO, M; LORES ARNAIZ, M R; DE ERAUSQUIN, G

Viena

Congreso; 5th Forum of European Neuroscience; 2006

Federation of European Neuroscience Societies (FENS)

Influenza infection of pregnant mice results in histopathological and behavioral changes in the offspring (Shi, 2003; Fatemi, 2002). We compared the behavior of offspring from mothers infected with two influenza strains. BALB/c mice were infected by intranasal instillation with neurovirulent A/New Winsconsin/33 (H1N1) strain (WSN), respiratory A/New Caledonia/20/99-like (H1N1) strain (NCAL) or Phosphate Buffer Saline (PBS) at 9 days of pregnancy. Behavioral studies of 5 weeks old offspring included 3 Open Field (OF) sessions, Novel Object (NO) and Elevated Plus Maze (EPM). Only pups from seroconverted mothers were included. WSN-exposed pups (n=18; 7 males) travelled more distance on the 3 OF sessions (p=.05, p=.01, p=.01) and spent more time on central squares at session 2 and 3 (p=.05, p=.01) than PBS-exposed pups (n=16; 9 males). WSN-exposed pups and NCAL (n=13; 4 males) contacted the NO more frequently (p=.001, p=.05) and spent more time exploring it (p=.001, p=.05) than PBS-exposed pups. WSN-exposed male pups spent more time in open arms in EPM (p=.01). Enhaced locomotion and decrease anxiety were observed in WSN-exposed pups while NCAL-exposed pups evidenced a minor effect on anxiety level. These behavioral results correlate with previous in vitro and in vivo studies demonstrating neuronal death and significant reduction of dopaminergic neurons in SN and VTA after infection with both influenza strains (Landreau, 2005). Ozawa (2005) found that poly (I:C) induced immulogical response on pregnancy caused abnormalities in adult offsprings but not when young. In our study, immune response may be involved since WSN infection produced higher maternal antibody titers than NCAL infection (p=.05) but behavioral disturbancies in young mice and in vitro direct viral effects suggest that other mechanisms might be implicated.