Abstract
behavioral, endocrine, and neurochemical implications. This experience causes behavioral and neurochemical changes that involve several brain areas important for the expression of maternal behavior. The present study showed that lactating rats exhibited reduced general locomotor activity in the open field test compared with virgin animals. Our hypothesis was that nucleus accumbens dopamine, which regulates maternal behavior in lactating rats, is also involved in the low expression of maternal locomotion in the open field test observed during the early stages of lactation and reflects decreased motivation. Initially we compared open field behavior in virgin and lactating rats to confirm our previous data. Thus, the in vivo release of dopamine in the nucleus accumbens in virgin and lactating female rats was measured. Perfusate concentrations of extracellular dopamine and its metabolites showed no differences between virgin and lactating rats. Thus, the reduced general activity observed in lactating rats might not be related to intra-nucleus accumbens dopamine control. Keywords: maternal behavior, virgin rats, lactating rats, nucleus accumbens, dopamine.
Highlights
The maternal brain undergoes remarkable physiological and behavioral changes in the peripartum period to meet the demands of the offspring (Numan & Woodside, 2010; Bosch, 2011)
We previously showed that dopamine receptors in the nucleus accumbens (NAc) play a role in ongoing maternal behavior (Silva, Bernardi, Cruz-Casallas, & Felicio, 2003)
The present study confirmed previous results by showing that lactating rats exhibit decreased locomotor frequency in the open field compared with virgin animals (Silva et al, 1997)
Summary
The maternal brain undergoes remarkable physiological and behavioral changes in the peripartum period to meet the demands of the offspring (Numan & Woodside, 2010; Bosch, 2011). Changes in the physiological state of mammals are usually related to endocrine and neural changes (Numan & Stolzenberg, 2008; Stolzenberg et al, 2007; Nasello, Tieppo, & Felicio, 1995; Felicio, Florio, Sider, Cruz-Casallas, & Bridges, 1996; Bridges, Felicio, Pellerin, Stuer, & Mann, 1993) and reflect behavioral adjustments or alterations (Numan, 1994; Numan & Woodside, 2010; Teodorov, Bernardi, Ferrari, Fior-Chadi, & Felicio, 2010). Rats and mice tend to avoid brightly illuminated, novel, and open spaces, so the open field environment is an anxiogenic stimulus that allows for the measurement of anxiety-induced locomotor activity and exploratory behavior. When the laboratory conditions are maintained with low illumination and without environmental stimuli, rats or mice express mainly exploratory and motor activity rather than anxiety-like responses
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
