Nucleus incertus promotes cortical desynchronization and behavioral arousal
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- 作者：Sherie Ma ; Giancarlo Allocca ; Emma K. E. Ong-Pålsson…
- 关键词：Arousal ; Nucleus incertus ; Cortical desynchronization ; Vigilance ; Locomotion
- 刊名：Brain Structure and Function
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：222
- 期：1
- 页码：515-537
- 全文大小：
- 刊物主题：Neurosciences; Cell Biology; Neurology;
- 出版者：Springer Berlin Heidelberg
- ISSN：1863-2661
- 卷排序：222
文摘
Arousal and vigilance are essential for survival and relevant regulatory neural circuits lie within the brainstem, hypothalamus and forebrain. The nucleus incertus (NI) is a distinct site within the pontine periventricular gray, containing a substantial population of GABAergic neurons with long-range, ascending projections. Existing neuroanatomical data and functional studies in anesthetized rats, suggest the NI is a central component of a midline behavioral control network well positioned to modulate arousal, vigilance and exploratory navigation, yet none of these roles have been established experimentally. We used a chemogenetic approach—clozapine-N-oxide (CNO) activation of virally delivered excitatory hM3Dq-DREADDs—to activate the NI in rats and examined the behavioral and physiological effects, relative to effects in naïve rats and appropriate viral-treated controls. hM3Dq activation by CNO resulted in long-lasting depolarization of NI neurons with action potentials, in vitro. Peripheral injection of CNO significantly increased c-Fos immunoreactivity in the NI and promoted cortical electroencephalograph (EEG) desynchronization. These brain changes were associated with heightened arousal, and increased locomotor activity in the homecage and in a novel environment. Furthermore, NI activation altered responses in a fear conditioning paradigm, reflected by increased head-scanning, vigilant behaviors during conditioned fear recall. These findings provide direct evidence that the NI promotes general arousal via a broad behavioral activation circuit and support early hypotheses, based on its connectivity, that the NI is a modulator of cognition and attention, and emotional and motivated behaviors.