Effect of chronic administration and withdrawal of caffeine on motor function, cognitive functions, anxiety, and the social behavior of BLC57 mice.

OBJECTIVES: The cognitive functions, motor coordination, and social behavior were studied in rodents after adding different doses of caffeine in their drinking water. METHODOLOGY: BLC57 mice were divided into four groups: Control (n = 8), chronic moderate dose (n = 8, Ch] MD), Ch high dose (n = 8, Ch HD), and withdrawal (n = 8, WD). Caffeine was administered for 1 month to all groups. Spatial memory was tested by Morris water maze, motor coordination by rotarod (RR), social behavior by (Crawley's test), and anxiety by elevated plus maze (EPM) test. RESULTS: In water maze, the latency to reach the platform was significantly shorter in Ch MD group compared to the control and the Ch HD groups. WD group showed the worst performance. RR results showed that the groups treated with caffeine performed poor in comparison to the control group where their latency to fall was significantly less. In the three-chamber test, the Ch MD group showed enhanced sociability (session 1) and social novelty behavior (session 2). On the other hand, both Ch HD and WD showed a lack in sociability and a deficit in social novelty. In the EPM, results showed that all caffeine administrated mice where more anxious than the control group. CONCLUSION: We concluded that chronic administration of caffeine in MD resulted in enhancement of spatial memory, motor functions, sociability, and social novelty. The anxiety in these animals was, however, increased. On the other hand, Ch HD caffeine had opposite effects on all the parameters except for anxiety.

Acute Administration of Caffeine: The Effect on Motor Coordination, Higher Brain Cognitive Functions, and the Social Behavior of BLC57 Mice.

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.

High-normal blood glucose levels may be associated with decreased spatial perception in young healthy adults.

The negative effects of high normal glucose on cognitive function were previously reported in euglycemic individuals of middle age and the elderly population. This study aimed at examining the effect of baseline blood glucose levels on spatial ability, specifically verticality perception on the computerized rod and frame test (CRFT) in young healthy adults. 63 healthy male medical students (age range from 18-23 years), of whom 30 were non-fasting outside the month of Ramadan and 33 fasting during Ramadan of the year 2016, were recruited in order to create varying degrees of glycemia during which verticality perception was carried out. Baseline blood glucose reading was obtained prior to commencing the CRFT test. Blood glucose levels at the time of testing decreased as the duration between the last meal and testing increased. A blood glucose range of 62-117 mg/dl was achieved among participants for this study. Linear regression analysis showed that blood glucose level at testing correlated positively with all alignment spatial error parameters, indicating a probable reduction of spatial perception ability with higher blood glucose levels. These results are consistent with other cognitive studies in older healthy humans and emphasize the critical impact of early glucose dys-homeostasis on cognitive function. They also indicate that elevated blood glucose may affect cognitive functioning outside of the usual complications of diabetes.