LITHIUM-CHLORIDE AND INESCAPABLE, UNSIGNALED TAIL SHOCK DIFFERENTIALLY AFFECT MEAL PATTERNS OF RATS

Several motivational states, such as malaise, fear, and satiety, reduc e spontaneous food ingestion by rats, and differentiation of these sta tes is often desirable. The present study used the spontaneous meal pa ttern to this end. The illness-inducing toxin lithium chloride delayed initiation of the first postinjection meal, and that meal was smaller and eaten more slowly (Experiments 1A and 1B). Rats exposed to tail s hock also subsequently took longer to initiate meals, but meals were e aten faster and were slightly larger relative to control conditions (E xperiment 2). These changes in meal patterns are different from those produced by satiety-related hormones, such as CCK or insulin, which so lely reduce meal size in paradigms designed to assess physiological re gulation of food intake. Taken together, these findings attest to the ability of meal patterns to distinguish malaise, fear, and satiety fro m one another.