A novel neural substrate for the transformation of olfactory inputs into motor output.
A novel neural substrate for the transformation of olfactory inputs into motor output.
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DOI：
10.1371/journal.pbio.1000567
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发表时间：
2010-12-21
期刊：
影响因子：
9.8
通讯作者：
Dubuc R
中科院分区：
文献类型：
--
作者：
Derjean D;Moussaddy A;Atallah E;St-Pierre M;Auclair F;Chang S;Ren X;Zielinski B;Dubuc R
七鳃鳗的解剖和生理实验揭示了将嗅觉输入转化为运动输出的神经回路，这在脊椎动物中是未知的。人们普遍认为动物对气味的反应是通过产生或调节特定的运动行为来实现的。这些反应对日常活动、繁殖和生存都很重要。在海七鳃鳗中，当排卵的雌性被雄性信息素吸引到产卵地点后，交配就发生了。脊椎动物嗅觉-运动行为反应的普遍性和可靠性表明嗅觉系统与控制运动的大脑区域之间存在紧密耦合。然而，电路和潜在的细胞神经机制在很大程度上仍然未知。利用七鳃鳗脑准备、电生理学、钙成像和尿道追踪实验，我们描述了负责将嗅觉输入转化为运动输出的神经基质。我们发现，自然产生的气味和信息素的嗅觉刺激在网状脊髓细胞（运动的命令神经元）中引起了巨大的兴奋反应。我们还确定了这个回路的解剖学和生理学。嗅觉输入在嗅球内侧、后结节、中脑运动区传递，最终到达后脑的网状脊髓细胞。这种嗅觉-运动通路的激活产生了有节奏的腹侧根放电和游泳运动。我们的研究弥合了脊椎动物行为和细胞神经机制之间的差距，确定了中枢神经系统中一个特定的子系统，致力于对嗅觉输入产生运动反应。动物的行为，包括运动，可以由嗅觉线索驱动，如信息素或食物来源。在脊椎动物中，允许嗅觉输入转化为运动反应的神经基质（神经解剖连接和生理信号）仍然未知。在本研究中，我们在七鳃鳗中发现了这样一种神经基质。在这里，来自外界的嗅觉信号被传递到脑干下部的网状脊髓神经元，后者向脊髓提供下行运动指令。我们发现这个回路起源于嗅球的内侧部分，连接在后结节，一个腹侧间脑结构。这些输入随后被传递到中脑运动区，该区域广泛地投射到脑干网状脊髓神经元，从而激活运动。我们的研究结果阐明了七鳃鳗大脑中一个特定的专用神经基质，它是嗅觉运动反应的基础，这是由食物相关或信息素嗅觉线索激活的。确定这种途径是否在所有脊椎动物中都保留下来将是一件有趣的事情。
Anatomical and physiological experiments in the lamprey reveal the neural circuit involved in transforming olfactory inputs into motor outputs, which was previously unknown in a vertebrate. It is widely recognized that animals respond to odors by generating or modulating specific motor behaviors. These reactions are important for daily activities, reproduction, and survival. In the sea lamprey, mating occurs after ovulated females are attracted to spawning sites by male sex pheromones. The ubiquity and reliability of olfactory-motor behavioral responses in vertebrates suggest tight coupling between the olfactory system and brain areas controlling movements. However, the circuitry and the underlying cellular neural mechanisms remain largely unknown. Using lamprey brain preparations, and electrophysiology, calcium imaging, and tract tracing experiments, we describe the neural substrate responsible for transforming an olfactory input into a locomotor output. We found that olfactory stimulation with naturally occurring odors and pheromones induced large excitatory responses in reticulospinal cells, the command neurons for locomotion. We have also identified the anatomy and physiology of this circuit. The olfactory input was relayed in the medial part of the olfactory bulb, in the posterior tuberculum, in the mesencephalic locomotor region, to finally reach reticulospinal cells in the hindbrain. Activation of this olfactory-motor pathway generated rhythmic ventral root discharges and swimming movements. Our study bridges the gap between behavior and cellular neural mechanisms in vertebrates, identifying a specific subsystem within the CNS, dedicated to producing motor responses to olfactory inputs. Animal behaviors, including locomotion, can be driven by olfactory cues, such as pheromones or food sources. The neural substrate (neuroanatomical connections and physiological signals) that permits the transformation of olfactory inputs into locomotor responses is still unknown in vertebrates. In the present study, we identify such a neural substrate in the lamprey. Here, olfactory signals from the outside world are transmitted to the reticulospinal neurons in the lower brainstem, which provide the descending locomotor command to the spinal cord. We found that this circuit originates in the medial portion of the olfactory bulb and that connections are made in the posterior tuberculum, a ventral diencephalic structure. These inputs are then conveyed to the mesencephalic locomotor region, known to project extensively to brainstem reticulospinal neurons and thereby activate locomotion. Our results illuminate a specific dedicated neural substrate in the brain of lampreys that underlies olfactory-motor responses, which is activated by both food-related or pheromonal olfactory cues. It will be of interest to determine whether such a pathway is preserved in all vertebrates.
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影响因子：
3.4
作者：
Le Ray, D;Brocard, F;Dubuc, R
通讯作者：
Dubuc, R
DOI：
10.1073/pnas.0900470106
发表时间：
2009-06-16
影响因子：
11.1
作者：
Koide, Tetsuya;Miyasaka, Nobuhiko;Yoshihara, Yoshihiro
通讯作者：
Yoshihara, Yoshihiro
影响因子：
56.9
作者：
Li, WM;Scott, AP;Gage, DA
通讯作者：
Gage, DA
影响因子：
3.8
作者：
Li, W;Sorensen, P W;Gallaher, D D
通讯作者：
Gallaher, D D
DOI：
10.1073/pnas.0409009101
发表时间：
2005-03-01
影响因子：
11.1
作者：
Gray, JM;Hill, JJ;Bargmann, CI
通讯作者：
Bargmann, CI