Anxiogenic Effects of Stress on Motor Control

For many animals, stress is an inevitable part of life caused by such situations as social interactions, pursuit by a predator, and (for humans at least) rush-hour traffic. The effects of these stressors may be manifested in behavior and physiology. Rats are often used in laboratory experiments to study such manifestations. The types and degrees of stress can be varied with multiple consequences. One type, prone restraint, is a mild stressor whose impact differs among rat strains. Of particular interest for the present study are the Occidental Low-Saccharin (LoS) and High-Saccharin (HiS) lines. These rats have been used to study relationships between taste and variables such as stress and emotionality. One unanswered question is which of the two lines is more \u27normal.\u27 Outbred rats (from the parent stock) provided a \u27normal\u27 line to which LoS and HiS rats could be compared. Another question of interest was whether any behavioral effects of stress reflected anxiety as opposed to, for example, depression. Anxiolytic (anxiety reducing) drugs can be used to address this question, on the theory that effects of stress will be reduced if they are indeed caused by anxiety. The present study focused on the effects of restraint stress on motor coordination, as indicated by a battery of behavioral tests. The hypothesis was that LoS rats, because of their greater emotionality and stress vulnerability, would show more motor control deficits than HiS rats, more so after restraint stress. It was predicted that Outbred rats would have intermediate scores