Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan.
Brain Struct Funct. 2020 Sep;225(7):2057-2076. doi: 10.1007/s00429-020-02109-3. Epub 2020 Jul 14.
Ventromedial thalamic axons innervate cortical layer I and make contacts onto the apical dendritic tuft of pyramidal neurons. Optical stimulation of ventromedial thalamic axon terminals in prefrontal cortical areas in mouse brain slices evokes responses in corticocortical, corticothalamic and layer I inhibitory interneurons. Using anterograde tracing techniques and immunohistochemistry in male Sprague-Dawley rats, we provide anatomical evidence that ventromedial thalamic axon terminals in prelimbic cortex make contacts onto pyramidal neurons and, in particular, onto corticostriatal neurons as well as layer I inhibitory interneurons. Using stereology, we made quantitative estimates of contacts in uppermost prelimbic layer I onto dendrites of pyramidal neurons, corticostriatal neurons and layer I inhibitory interneurons. Prefrontal cortex has long been associated with decision making. Specifically, corticostriatal neurons in rat prelimbic cortex play an important role in cost-benefit decision making. Although recent experiments have detailed the physiology of this area in thalamocortical circuits, the extent of the impact of ventromedial thalamic input on corticostriatal neurons or layer I inhibitory interneurons has not been explored. Our quantitative anatomical results provide evidence that most ventromedial thalamic input to pyramidal neurons is provided to corticostriatal neurons and that overall more contacts are made onto the population of excitatory than onto the population of inhibitory neurons.
腹侧丘脑轴突支配皮质层 I，并与锥体神经元的树突顶丛形成接触。在小鼠脑切片中，光刺激前额叶皮层区域的腹侧丘脑轴突末梢，会引起皮质间、皮质丘脑间和 I 层抑制性中间神经元的反应。在雄性 Sprague-Dawley 大鼠中，我们使用顺行示踪技术和免疫组织化学方法，提供了腹侧丘脑轴突末梢在前扣带回皮层与锥体神经元接触的解剖学证据，特别是与皮质纹状体神经元和 I 层抑制性中间神经元接触。通过体视学，我们对最上层前扣带皮层 I 层中锥体神经元、皮质纹状体神经元和 I 层抑制性中间神经元树突上的接触进行了定量估计。前额叶皮层长期以来一直与决策有关。具体来说，大鼠前扣带皮层的皮质纹状体神经元在成本效益决策中起着重要作用。尽管最近的实验详细描述了丘脑皮质回路中这一区域的生理学，但腹侧丘脑输入对皮质纹状体神经元或 I 层抑制性中间神经元的影响程度尚未得到探索。我们的定量解剖学结果提供了证据，表明腹侧丘脑对锥体神经元的大多数输入是提供给皮质纹状体神经元的，并且总体上与兴奋性神经元相比，与抑制性神经元的接触更多。
