Excessive caffeine consumption causes adverse health effects. The effects of moderate and high doses of caffeine consumption on the motor coordination, cognitive brain functions, and the social behavior in mice were studied. Animals were divided into three groups: control group, moderate dose group (Ac MD), and high dose group (Ac HD). The animals were tested after 7 days of caffeine administration. A rotarod test for motor coordination showed that the mice of the moderate dose group could stay on the rotating rod longer before falling in comparison to the control group and the high dose group. A water maze test for learning and memory showed better performance of mice receiving the moderate dose of caffeine compared to the other groups. Animals that were administered moderate as well as high doses of caffeine showed no sociability and no preference for social novelty in the three-chamber test used to test social behavior. In an elevated plus maze test, control animals showed no anxiety-like behavior while mice from both of the groups administered with caffeine showed anxiety-like behaviors. Our data conclude that the effects of caffeine on higher brain functions depend on the administration dose. When caffeine was given in moderate doses, it resulted in enhancement of memory and motor coordination functions. However, high doses caused defects in memory and learning. The social behavior of the mice, as determined by the level of anxiety and sociability, was affected negatively by moderate as well as high dose caffeine administration.

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Hearing impairment affects over two-thirds of adults with diabetes. We investigated whether rat models of type 1 and type 11 diabetes display impaired auditory function. Tympanometry measurements were conducted in Sprague-Dawley rats (control, n = 20), streptozotocin-induced type I diabetic Sprague-Dawley rats (n = 20) at 42 -56 days old; Zucker rats (Hos: ZFDM-Lean (fa/+, n = 20) and Zucker Type 2 Diabetic rats (ZFDM (Hos: ZFDMfa/fa); n = 20)), 90 days old. All rats were male. Control animals had normal type A tympanograms. Tweny one (75%) of the tympanic membranes in the diabetic type I group produced abnormal tympanograms: 46% were type B, 28% had no peak found, and 1% were type C. The ear canal measurements were lower in the left ear in type I mice (0.19 ± 0.07) and higher in the left ear for type II mice (0.23 ± 0.15 ml) compared to the controls of 0.39 ± 0.14 ml) and (0.2 ± 0.12 ml) respectively (P < 0.0001). The compliances for the right ear and left ear were lower for the type II diabetic group (0.18 ± 0.05 ml) and (0.18 ± 0.05 ml) compared to the control group (0.28 ± 0.19 ml) and (0.28 ± 0.49 ml) (P < 0.0001) respectively. In conclusion, control rats exhibited type A tympanograms with a highly functional middle ear system. Diabetic type I rats (n = 20) mostly exhibited type B tympanograms with a less compliant middle ear system. Compliance was reduced in the diabetic type I and II animals compared to the control. Future studies should utilise histological methods alongside tympanometry. Sections of the middle ear could be used to analyze ossicle size and confirm size differences. This information would be useful in avenues for treatment options for hearing loss in diabetes.

Heavy caffeine consumption is associated with adverse health effects. The effects of moderate and high doses of caffeine mixed with drinking water on the motor coordination, learning and memory and the social behavior in mice were studied in mice. Animals were divided into 3 groups: control group, moderate dose group (Ac MD) and high dose group (Ac HD). The animals were tested after 7 days of caffeine administration. Rota rod test for motor coordination showed that the mice of the moderate dose group could stay more time on the rotating rod before they fall than the control group and the high dose group. Water maze test for learning and memory showed better performance of mice receiving moderate dose of caffeine compared to the other groups. Animals that were administered moderate as well as high doses of caffeine showed no sociability and no preference for social novelty in the three-chamber test used to test the social behavior. In elevated plus maze, control animals showed no anxiety-like behavior while mice administered with caffeine were both showing anxiety-like behaviors. We concluded that acute administration of moderate dose of caffeine to mice could enhance their spatial memory and motor coordination. High doses however caused defects in memory and learning. The social behavior as the level of anxiety and sociability was affected negatively by moderate as well as high dose caffeine administration.Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 4

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