Koike Hiroyuki, Demars Michael P, Short Jennifer A, Nabel Elisa M, Akbarian Schahram, Baxter Mark G, Morishita Hirofumi
Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Neuropsychopharmacology. 2016 Mar;41(4):1014-23. doi: 10.1038/npp.2015.229. Epub 2015 Jul 30.
Attention is disrupted commonly in psychiatric disorders, yet mechanistic insight remains limited. Deficits in this function are associated with dorsal anterior cingulate cortex (dACC) excitotoxic lesions and pharmacological disinhibition; however, a causal relationship has not been established at the cellular level. Moreover, this association has not yet been examined in a genetically tractable species such as mice. Here, we reveal that dACC neurons causally contribute to attention processing by combining a chemogenetic approach that reversibly suppresses neural activity with a translational, touchscreen-based attention task in mice. We virally expressed inhibitory hM4Di DREADD (designer receptor exclusively activated by a designer drug) in dACC neurons, and examined the effects of this inhibitory action with the attention-based five-choice serial reaction time task. DREADD inactivation of the dACC neurons during the task significantly increased omission and correct response latencies, indicating that the neuronal activities of dACC contribute to attention and processing speed. Selective inactivation of excitatory neurons in the dACC not only increased omission, but also decreased accuracy. The effect of inactivating dACC neurons was selective to attention as response control, motivation, and locomotion remain normal. This finding suggests that dACC excitatory neurons play a principal role in modulating attention to task-relevant stimuli. This study establishes a foundation to chemogenetically dissect specific cell-type and circuit mechanisms underlying attentional behaviors in a genetically tractable species.
注意力障碍在精神疾病中很常见,但对其机制的了解仍然有限。这种功能缺陷与背侧前扣带回皮质(dACC)的兴奋性毒性损伤和药理学去抑制有关;然而,在细胞水平上尚未建立因果关系。此外,这种关联尚未在小鼠等具有遗传易处理性的物种中进行研究。在这里,我们通过将一种可逆抑制神经活动的化学遗传学方法与基于触摸屏翻译的小鼠注意力任务相结合,揭示了dACC神经元对注意力加工有因果贡献。我们通过病毒在dACC神经元中表达抑制性hM4Di DREADD(仅由设计药物激活的设计受体),并使用基于注意力的五选择连续反应时任务来检验这种抑制作用的效果。在任务期间dACC神经元的DREADD失活显著增加了遗漏和正确反应潜伏期,表明dACC的神经元活动有助于注意力和加工速度。dACC中兴奋性神经元的选择性失活不仅增加了遗漏,还降低了准确性。dACC神经元失活的影响对注意力具有选择性,因为反应控制、动机和运动保持正常。这一发现表明,dACC兴奋性神经元在调节对与任务相关刺激的注意力方面起主要作用。本研究为在具有遗传易处理性的物种中化学遗传学剖析注意力行为背后的特定细胞类型和回路机制奠定了基础。