High resolution spatial mapping of nicotine action using pharmacologic magnetic resonance imaging.
Nicotine is one of the most addictive substances known. To better understand the mechanisms of action, we mapped the regional brain response to nicotine administration using pharmacologic magnetic resonance imaging (phMRI) in rats. We measured the regional response of relative cerebral blood volume (rCBV) in rats to a challenge of 0.07 mg/kg (0.43 micromol/kg) of nicotine. The areas of the brain with significant and reproducible changes in the rCBV response were (in descending order of magnitude) infralimbic cortex, hippocampus (subiculum), agranular insular/pyriform cortex, visual cortex, interpeduncular area, nucleus accumbens, cingulate cortex, thalamus, and septum. This pattern of response is consistent with stimulation of both cholinergic and dopaminergic neuronal pathways and is consistent with the known behavioral properties of nicotine. The peak CBV response to nicotine occurred between 9 and 13 min depending upon brain region, and the average full width half-maximum of the rCBV response was 27 min. The high spatial and temporal resolution of the phMRI technique lends itself well to further, more detailed, studies of nicotine dynamics.
Choi
Ji-Kyung
JK
Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA.
Mandeville
Joseph B
JB
Chen
Y Iris
YI
Kim
Young R
YR
Jenkins
Bruce G
BG
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply* / Q000187:drug effects*; D001931:Brain Mapping / Q000379:methods; D002536:Cerebral Arteries / Q000187:drug effects / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology; D004298:Dopamine / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D014029:Tobacco Use Disorder / Q000378:metabolism / Q000503:physiopathology
D018722:Nicotinic Agonists; D009538:Nicotine; D000109:Acetylcholine; D004298:Dopamine