Neural effects of methylphenidate and nicotine during smooth pursuit eye movements

• Published in: NeuroImage (Orlando, Fla.) Vol. 141; pp. 52 - 59
• Main Authors: Kasparbauer, Anna-Maria, Meyhöfer, Inga, Steffens, Maria, Weber, Bernd, Aydin, Merve, Kumari, Veena, Hurlemann, Rene, Ettinger, Ulrich
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2016; Elsevier Limited
• Subjects: Attention deficit hyperactivity disorder; Between-subjects design; Binding sites; Biomarkers; Blindness; Brain Mapping; Central Nervous System Stimulants - administration & dosage; Cognition & reasoning; Cognitive ability; Cognitive enhancer; Dopamine; Dose-Response Relationship, Drug; Double-Blind Method; Eye movement; Eye movements; Female; fMRI; Frontal Lobe - drug effects; Frontal Lobe - physiology; Functional magnetic resonance imaging; Humans; Information processing; Magnetic Resonance Imaging - methods; Male; Methylphenidate; Methylphenidate - administration & dosage; Motion Perception - drug effects; Motion Perception - physiology; Nicotine; Nicotine - administration & dosage; Nootropic Agents - administration & dosage; Placebo Effect; Psychomotor Performance - drug effects; Psychomotor Performance - physiology; Pursuit, Smooth - drug effects; Pursuit, Smooth - physiology; Receptive field; Schizophrenia; Smooth pursuit; Smooth pursuit eye movements; Stimulants; Studies; Treatment Outcome; Visual Fields - drug effects; Visual Fields - physiology; Young Adult; Smooth pursuit; fMRI; Cognitive enhancer; Eye movement; Methylphenidate; Nicotine
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2016.07.012

Nicotine and methylphenidate are putative cognitive enhancers in healthy and patient populations. Although they stimulate different neurotransmitter systems, they have been shown to enhance performance on overlapping measures of attention. So far, there has been no direct comparison of the effects of these two stimulants on behavioural performance or brain function in healthy humans. Here, we directly compare the two compounds using a well-established oculomotor biomarker in order to explore common and distinct behavioural and neural effects. Eighty-two healthy male non-smokers performed a smooth pursuit eye movement task while lying in an fMRI scanner. In a between-subjects, double-blind design, subjects either received placebo (placebo patch and capsule), nicotine (7mg nicotine patch and placebo capsule), or methylphenidate (placebo patch and 40mg methylphenidate capsule). There were no significant drug effects on behavioural measures. At the neural level, methylphenidate elicited higher activation in left frontal eye field compared to nicotine, with an intermediate response under placebo. The reduced activation of task-related regions under nicotine could be associated with more efficient neural processing, while increased hemodynamic response under methylphenidate is interpretable as enhanced processing of task-relevant networks. Together, these findings suggest dissociable neural effects of these putative cognitive enhancers. •We investigated neural and behavioural effects of nicotine and methylphenidate in 82 healthy males•A smooth pursuit eye movement paradigm was used in fMRI to investigate performance and BOLD effects•There was no influence of either compound on behavioural measures of smooth pursuit•The methylphenidate group exhibited increased left frontal eye field activation in contrast to the nicotine group