Figure 4.

The female response changes from pregnancy to postpartum. Females were exposed to an acute stressful event and trained 24 hours later on the classically conditioned eyeblink response using a trace paradigm. As shown previously, stress reduced the percentage of conditioned responses in adult females that were cycling. Stress also reduced conditioning in females that were pregnant and therefore not cycling. However, stress did not alter conditioning in females that were lactating. Upon removal of their offspring, lactation ceased and these females emitted a smaller percentage of conditioned responses after exposure to the stressful event (Leuner & Shors 2005).