Shocking! Stress Reduces Emotionality in Low-Saccharin-Consuming Rats Cameryn Garret and Mitzi Gonzalez

Stress can induce transient and long-term alterations in physiological and emotional vulnerability. A stressor?s impact depends on its intensity and duration, as well as individual differences in emotional reactivity. Low Saccharin (LoS) rats are an ideal population in which to study vulnerability because they respond more strongly to stress than High Saccharin (HiS) rats. In the present study, the effects of stress were measured on two dimensions: startle amplitude and hot plate latencies. Some rats were exposed to a moderate stressor. One group of LoS rats was given alprazolam, an anxiety-reducing drug, before the stressor. Later, rats were startle tested. Stressed HiS rats did not differ from unstressed HiS rats. However, stressed LoS rats startled less than unstressed LoS rats. Alprazolam blocked this effect. After the startle session, all rats were given a hot plate test. Again, prior stressors had no effect on HiS rats, but the non-stressed, non-startled LoS rat had longer hot plate latencies than all other LoS rats. The results from the startle and hot plate tests demonstrate that prior stress reduces the perceived intensity of less threatening events in emotionally vulnerable individuals