Cocaine-induced brain activation detected by dynamic manganese-enhanced magnetic resonance imaging (MEMRI).
Dynamic manganese-enhanced magnetic resonance imaging (MEMRI) detects neuronal activity based on the passage of Mn(2+) into active neurons. Because this mechanism is independent of any hemodynamic response, it is potentially ideal for pharmacological studies and was applied to investigate the acute CNS effects of cocaine in the rat. Dose-dependent, region-specific MEMRI signals were seen mostly in cortical and subcortical mesocorticolimbic structures. To verify the spatial accuracy and physiological mechanisms of MEMRI, neuronal activation following electrical forepaw stimulation revealed somatotopic signal enhancement in the primary and secondary somatosensory cortices, which was blocked by diltiazem, a Ca2+ channel antagonist. These data suggest that MEMRI may serve as a tool for investigating the effects of pharmacological agents and opens an application of MRI to study CNS drug effects at a systems level.
Lu
Hanbing
H
Neuroimaging Research Branch, National Institute on Drug Abuse (NIDA), Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA.
Xi
Zheng-Xiong
ZX
Gitajn
Leah
L
Rea
William
W
Yang
Yihong
Y
Stein
Elliot A
EA
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D001931:Brain Mapping / Q000379:methods; D003042:Cocaine / Q000494:pharmacology*; D004558:Electric Stimulation; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008345:Manganese; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D013003:Somatosensory Cortex / Q000187:drug effects / Q000502:physiology
D008345:Manganese; D003042:Cocaine