Meeting Abstract
Caffeine works through a variety of complex mechanisms to exert an often bidirectional set of functional and structural neurological changes in vertebrates. We investigated the effects of chronic caffeine exposure on functional recovery of the dorsal light reflex (DLR) in hemilabyrinthectomized common goldfish, Carassius auratus. In this lesion model, the unilateral removal of the vestibular organs results in temporary loss of gravitationally modulated postural control which is quantifiable via the DLR. We compared the functional recovery over 24 days of post-surgery goldfish perpetually held in a caffeine solution of 2.5 mg/L (n=10), 5.0 mg/L (n=10), 10.0 mg/L (n=11), or 0.0 mg/L control (n=9). Comparison to a sham surgery group (n=11) indicated statistically significant changes in the DLR of all hemilabyrinthectomized fish on day 1. The control group recovered over the study period and approached but did not reach sham surgery DLR. The 2.5 and 5.0 mg/L groups initiated postural recovery similar to controls but then returned to a stronger DLR. Beginning on day 10, the 5.0 and 10.0 mg/L caffeine groups diverged from the control and all three caffeine groups were statistically different from the control on days 15-24. Results suggest caffeine exposure at first is benign but prolonged exposure hinders functional recovery. Further studies are planned to elucidate the mechanism of action of caffeine on the DLR goldfish model.
