THE BEHAVIORAL AND PHARMACOLOGICAL EFFECTS OF CAFFEINE ON THE CONSUMPTION AND HEDONIC EVALUATION OF SUCROSE SOLUTIONS

The overconsumption of highly palatable, calorie dense food and drink is an important component in the etiology of obesity. Caffeine is a psychostimulant that is regularly consumed alongside highly palatable, calorie-dense beverages in the form of soft drinks, coffees, and energy drinks. Caffeine has been shown to positively shift the hedonic evaluation of beverages in humans, and increase the appetitive motivation to work for sucrose pellet rewards in rats. However, no animal research has examined the impact that caffeine has on the hedonic evaluation and licking microstructure of sweet solutions. In this thesis, the effect of caffeine on the intake and licking microstructure of rats offered a 10% sucrose solution was examined. In the first experiment, caffeine was added directly to the sucrose solution, whereas the second experiment examined the effects of systemic injections of caffeine on the consumption and licking microstructure of the non-caffeinated sucrose solution across 90-min licking sessions. The dependent variables examined were total solution consumed, mean length of licking bursts, number of licking bursts, and latency to initiate drinking. In the first experiment, the presence of caffeine in the solution increased total consumption across days with a trend towards increased burst length. Caffeine in the solution had no effect on latency or the number of bursts. When caffeine was administered systemically in the second experiment, only the moderate dose increased consumption. Following ten days of systemic administration of the moderate caffeine dose, consumption continued to increase, and additional trends towards an increased number of licking bursts and decreased latency were demonstrated. Taken together, these findings suggest that caffeine increases the consumption of palatable solutions, and that this is due to an increase in the hedonic evaluation of the solution when it contains caffeine. However, when administered systemically, these findings suggest that caffeine increases consumption via an increase in appetitive motivation.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2016

Author dc:creator

• Altherr, Everett Brace

• Behavioral Neuroscience

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/59286

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/59286