Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina.
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina; Durham Veterans Affairs Medical Center and Veterans Integrated Service Network Number 6 Mental Illness Research, Education, and Clinical Center, Durham, North Carolina.
Biol Psychiatry. 2011 Oct 15;70(8):794-799. doi: 10.1016/j.biopsych.2011.05.031. Epub 2011 Jul 18.
Previous functional magnetic resonance imaging studies have shown strong correlations between cue-elicited craving for cigarettes and activation of the superior frontal gyrus (SFG). Repetitive transcranial magnetic stimulation (rTMS) offers a noninvasive means to reversibly affect brain cortical activity, which can be applied to testing hypotheses about the causal role of SFG in modulating craving.
Fifteen volunteer smokers were recruited to investigate the effects of rTMS on subjective responses to smoking versus neutral cues and to controlled presentations of cigarette smoke. On different days, participants were exposed to three conditions: 1) high-frequency (10 Hz) rTMS directed at the SFG; 2) low-frequency (1 Hz) rTMS directed at the SFG; and 3) low-frequency (1 Hz) rTMS directed at the motor cortex (control condition).
Craving ratings in response to smoking versus neutral cues were differentially affected by the 10-Hz versus 1-Hz SFG condition. Craving after smoking cue presentations was elevated in the 10-Hz SFG condition, whereas craving after neutral cue presentations was reduced. Upon smoking in the 10-Hz SFG condition, ratings of immediate craving reduction as well as the intensity of interoceptive airway sensations were also attenuated.
These results support the view that the SFG plays a role in modulating craving reactivity; moreover, the results suggest that the SFG plays a role in both excitatory and inhibitory influences on craving, consistent with prior research demonstrating the role of the prefrontal cortex in the elicitation as well as inhibition of drug-seeking behaviors.
先前的功能磁共振成像研究表明，香烟线索诱发的渴求与额上回（SFG）的激活之间存在强烈的相关性。重复经颅磁刺激（rTMS）提供了一种非侵入性的手段来可逆地影响大脑皮质活动，这可以应用于测试 SFG 在调节渴求方面的因果作用的假设。
招募了 15 名志愿吸烟者，以调查 rTMS 对吸烟与中性线索的主观反应以及对香烟烟雾的控制呈现的影响。在不同的日子里，参与者接受了三种条件：1）高频（10 Hz）rTMS 作用于 SFG；2）低频（1 Hz）rTMS 作用于 SFG；3）低频（1 Hz）rTMS 作用于运动皮层（对照条件）。
吸烟与中性线索相比，渴求评分受到 SFG 的 10 Hz 与 1 Hz 条件的不同影响。吸烟线索呈现后的渴求在 10 Hz SFG 条件下升高，而中性线索呈现后的渴求在 1 Hz SFG 条件下降低。在 10 Hz SFG 条件下吸烟后，即时渴求降低的评分以及内感受气道感觉的强度也减弱。
这些结果支持了 SFG 在调节渴求反应性方面起作用的观点；此外，结果表明 SFG 在对渴求的兴奋和抑制影响中起作用，这与先前的研究一致，该研究表明前额叶皮层在药物寻求行为的诱发和抑制中起作用。
