Nicotine increases brain functional network efficiency.
Despite the use of cholinergic therapies in Alzheimer's disease and the development of cholinergic strategies for schizophrenia, relatively little is known about how the system modulates the connectivity and structure of large-scale brain networks. To better understand how nicotinic cholinergic systems alter these networks, this study examined the effects of nicotine on measures of whole-brain network communication efficiency. Resting state fMRI was acquired from fifteen healthy subjects before and after the application of nicotine or placebo transdermal patches in a single blind, crossover design. Data, which were previously examined for default network activity, were analyzed with network topology techniques to measure changes in the communication efficiency of whole-brain networks. Nicotine significantly increased local efficiency, a parameter that estimates the network's tolerance to local errors in communication. Nicotine also significantly enhanced the regional efficiency of limbic and paralimbic areas of the brain, areas which are especially altered in diseases such as Alzheimer's disease and schizophrenia. These changes in network topology may be one mechanism by which cholinergic therapies improve brain function.
Department of Psychiatry, University of Colorado Anschutz Medical Campus, Bldg. 500, Mail Stop F546, 13001 East 17th Place, Aurora, CO 80045, USA.
Korey P
KP
Wylie
Donald C
DC
Rojas
Jody
J
Tanabe
Laura F
LF
Martin
Jason R
JR
Tregellas
D000328:Adult; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D001931:Brain Mapping; D004526:Efficiency / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology*; D009538:Nicotine / Q000494:pharmacology*; D016037:Single-Blind Method
D009538:Nicotine