Are adenosine or adrenergic receptors altered in rat brain following chronic aspartame consumption?

Abstract

The specific aim of this study was to determine if long‐term aspartame administration in rats would cause a change in brain adrenergic or adenosine receptor densities, as a possible biochemical explanation for our previous results showing memory impairment in these animals. Male Sprague Dawley rats (225 g) received either plain tap water or aspartame in the drinking water (250 mg/kg/day) for 4 months. They were then were sacrificed, brains quickly removed and homogenate preparations made and frozen. Receptor numbers were determined using radioligands to label the receptors. Whole brain preparations, from aspartame‐treated rats showed a statistically significant increase in total apparent adenosine A1 receptor numbers when compared to controls (P<0.05). No significant differences were seen between control and treated animals for any of the adrenergic receptors measured. A trend was seen, however, for the alpha1 and alpha 2 receptors to be slightly decreased in the treated animals. More animals and various brain areas need to be studied to further define any differences. Studies such as these are needed to identify possible CNS effects of aspartame and correlate these with observed changes in memory or learning.