David A Johnson
Duquesne University, USA
Dr. Johnson is currently Professor of Pharmacology and Toxicology and the Division Head of Pharmaceutical Sciences of the Mylan School of Pharmacy and Graduate School of Pharmaceutical Sciences at Duquesne University, Pittsburgh, Pennsylvania. Dr. Johnson received his Ph.D. from the Massachusetts College of Pharmacy and Allied Health Sciences in 1990 majoring in Pharmacology with a minor in Neuroscience. Following the award of his degree, Dr. Johnson was a post-doctoral fellow in the laboratories of Dr. Bernard Lown at the Harvard School of Public Health and Dr. Richard J. Wurtman at Interneuron Pharmaceuticals. His primary scholarly interests include cholinergic function in learning, memory and attention. Dr. Johnson has authored over 50 publications in various areas of Pharmacology, several book chapters and two patents. Most recently, Dr. Johnson directed a clinical trial of the cognitive enhancing effects of an acetylcholine precursor and excitatory neuromodulators
The purpose of this randomized control clinical trial was to determine whether choline in combination with several doses of caffeine, could facilitate short-term visual and verbal memory and attention in adult and middle aged human subjects with normal cognitive function. The effects of several doses of caffeine in combination with choline on short-term visual and verbal memory, blood pressure and heart rate were assessed in 125 healthy adult and middle-aged men and women using six standardized tests from the Wide Range Assessment of Memory and Learning, Second Edition (WRAML 2). Tests included: Verbal Learning, Design Memory, Picture Memory, Story Memory, Finger Windows and Number/Letter. Group comparisons utilized one-way analysis of variance with Dunnett’s test post-hoc. Subjects administered caffeine 25 mg /choline 2 g scored significantly higher on tests for short-term visual memory than the placebo group. Conversely, the caffeine 50 mg /choline 2g treatment group scored significantly lower on tests for short-term verbal memory and attention than the placebo group. There were no significant differences in memory test scores between men and women and no significant changes in blood pressure or heart rate following administration of any of the treatment combinations. These results suggest that oral caffeine 25 mg in combination with choline 2 g may enhance short-term memory in healthy adults without affecting cardiovascular function.