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Thyroidectomized cats and cats with pontile lesions exhibit the same abnormal grooming behavior. Investigations were conducted to determine whether the abnormal grooming behavior in cats with pontile lesions was attributable to a hypothyroid condition. Administration of thyroid hormones abolished the abnormal behavior of thyroidectomized cats but was without effect in cats with pontile lesions. Studies of brain and blood levels of thyroid hormones in cats with pontile lesions failed to detect any differences from normal cats, and normal effects of thyroid hormones on evoked potentials to light flashes and to clicks were obtained in cats with pontile lesions. It was concluded that any thyroid dysfunction that may exist in the cats with pontile lesions was not involved in the genesis of the abnormal grooming behavior. Because the abnormal grooming behavior fluctuates rhythmically during the year, an endocrine hypothesis was entertained as the source of the fluctuations; endocrine concomitants of the abnormal behavior were investigated with longitudinal studies. The urinary excretion of 11hydroxycorticoids exhibited a significant negative correlation with the abnormal behavior. When compared with that of normal cats, the plasma level of 11-hydroxycorticoids of thyroidectomized cats was significantly decreased. Intramuscular injections of 11-hydroxycorticoids abolished the abnormal behavior in both thyroidectomized cats and cats with pontile lesions. These results considered together with previous findings indicate that thyroidectomy and pontile lesions induce similar changes in 11-hydroxycorticoid and serotonergic functions-changes that are critical features of the physiological bases of the abnormal grooming behavior in both groups.After pontile lesions, consummatory mally directed to the part of the body surface grooming behaviors of the cat are elicited that is tactually stimulated (complete deby tactile stimulation. The normally pre-tails are given by Randall, 1964). Thus the ceding appetitive components of the be-lesion induces an elicitable disintegration of havior do not occur. When you touch a cat the appetitive and consummatory componwith a pontile lesion on the back, the con-ents of grooming behavior. The importance summatory grooming behavior that is nor-of the appetitive-consummatory dichotomy mally directed to the back, the scratching was recognized by Sherrington (1906, pp. bite, is emitted immediately, occurring in 326 ff.) and first systematically studied by midair and thus with no adaptive or func-Craig (1918). More recent analyses of betional role. The consummatory response havior in these terms include the work of that is emitted is the response that is nor-Ewert Kupfermann (1974).

Cats with midbrain lesions exhibit an abnormal dissoeiation between appetitive and eonsummatory grooming behaviors. Periodie regression analyses of two sets of behavioral da ta from groups studied in different years revealed a 4-month rhythm, with the same timing in both years. Various long-term endoerine rhythms that may be involved in the rhythmie disintegration of grooming behavior are diseussed.

Cats with midbrain lesions exhibit an abnormal dissociation between appetitive and consummatory grooming behaviors and some signs of hypothyroidism. To determine jf a hypothyroid state causes the abnormal dissociation, six cats were thyroidectomized and their behavior monitored. The thyroidectomized cats exhibited the same abnormal dissociation in grooming behavior as did the cats with midbrain lesions. However, certain considerations, including the latency and time course of the thyroidectomized-induced changes, suggest that the hypothyroid state is not directly involved, but rather brings about other endocrine and metabolic changes that are involved in the production of the behavioral abnormality.Ouring a study of abnormal grooming behaviors that were induced by lesions of the caudal midbrain region, histological signs of thyroid dysfunction were found (RandalI, 1964). Subsequent investigations revealed that the grooming abnormality waxed and waned concomitantly with rhythmic fluctuations in thyroid activity (Randali & Littschwager, 1967). The grooming a bnormalities occur most frequently in the fall of the year, a time when the normal maximum in thyroid activity occurs. Ouring the spring, a time of the normal troughs in thyroid activity, the cats with brain-stem lesions are normal, exhibiting none of the abnormal behavior that was present in the fall.The abnormal grooming behavior, which appears after brain-stem lesions, consists of a dissociation between appetitive and consummatory grooming behaviors. The dissociation is detected by directing light tactile stimuli to the body surface of the ca!. These light tactile stimuli, which have no effect on the normal cat, elicit three consummatory grooming behaviors. The particular consummatory behavior that is elicited depends on the part of the body surface that receives the tactile stimuli: Touth the head or neck or shoulder of the cat and a nonoriented nonfunctional scratching movement of the foot is elicited; stroke the lateral surface of the trunk and the tongue is protruded and a lick occurs; touch the dorsal surface of the body and a nondirected grooming bite occurs in midair. These three consummatory behaviors occur in normal cats at the end of orienting behaviors but are elicited in lesioned cats by tactile stimuli without the normally preceding appetitive components.

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