Abstract # 200:

Scheduled for Saturday, August 20, 2005 10:30 AM-10:45 AM: Session 14 (Mayfair Room) Oral Presentation


FLOATING LIMB ACTIVITY: POSSIBLE CLUES TO PHYSIOLOGICAL UNDERPINNINGS

K. L. Bentson, C. M. Crockett, H. B. Montgomery, D. M. Anderson and S. T. Kelley
Washington National Primate Res. Ctr., University of Washington, Seattle, WA 98195-7330, USA
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     Floating limb activity (FLA), in which a leg or arm is elevated apparently without volition, has been observed in four monkey species (Macaca nemestrina, M. fascicularis, M. mulatta, and Papio cynocephalus) at WaNPRC. FLA occurs in immature and adult monkeys. Four types of evidence suggest this phenomenon has physiological underpinnings. 1) FLA was observed acutely in some monkeys after procedures that may produce transient physical discomfort. We tested the hypothesis that physical discomfort influences FLA by administering the anti-inflammatory analgesic ketoprofen to 11 monkeys with chronic FLA. There was a within-subjects reduction in FLA (GLM ANOVA, P < 0.05) and total abnormal behaviors (P < 0.0001). 2) Amphetamine administration has been shown to induce floating limb in at least two monkey species (Levin, 1990). Amphetamines alter CNS dopamine levels, which are abnormal in humans with some limb movement disorders. 3) 3 of 27 newly imported Indonesian M. nemestrina engaged in FLA; compared to the other 24, they had elevated levels of lymphocytes, basophils, monocytes (Mann-Whitney U, P < 0.01), platelets, and white blood cells (P < 0.05). 4) FLA was typically observed in the afternoon but rarely seen in the morning, suggesting a circadian influence. Self-biting was observed in more than 70% of monkeys that did FLA. Identifying the physiological underpinnings of floating limb activity may provide tools for reducing the incidence and severity of FLA and self-biting. NIH Grant RR00166.