Locomotion, Theta Oscillations, and the Speed-Correlated Firing of Hippocampal Neurons Are Controlled by a Medial Septal Glutamatergic Circuit
Locomotion, Theta Oscillations, and the Speed-Correlated Firing of Hippocampal Neurons Are Controlled by a Medial Septal Glutamatergic Circuit
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DOI：
10.1016/j.neuron.2015.05.001
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发表时间：
2015-06-03
期刊：
影响因子：
16.2
通讯作者：
Remy, Stefan
中科院分区：
文献类型：
--
作者：
Fuhrmann, Falko;Justus, Daniel;Remy, Stefan
在运动开始之前，海马体经历了向专门处理空间相关输入的活动状态的转变。这种大脑状态的转变与CA1锥体神经元放电频率的增加和theta振荡的发生有关，这两者都与运动速度有关。然而，运动活动与海马体振荡和神经元放电率有关的神经回路尚未解决。在这里，我们揭示了一个由谷氨酸(VGluT2(+))神经元介导的隔区-海马区电路，该神经元在运动开始前被激活，控制运动的启动和速度以及theta振荡的夹带。此外，通过隔-海马区向齿状回/东方核中间神经元的投射，该回路以一种运动依赖的方式调节对CA1锥体神经元Schaffer侧支和穿支路输入的前馈抑制。随着运动速度的加快，内侧隔区VGluT2神经元活动的增加转化为轴体去极化的增加和CA1锥体神经元更高的放电频率。
Before the onset of locomotion, the hippocampus undergoes a transition into an activity-state specialized for the processing of spatially related input. This brain-state transition is associated with increased firing rates of CA1 pyramidal neurons and the occurrence of theta oscillations, which both correlate with locomotion velocity. However, the neural circuit by which locomotor activity is linked to hippocampal oscillations and neuronal firing rates is unresolved. Here we reveal a septo-hippocampal circuit mediated by glutamatergic (VGluT2(+)) neurons that is activated before locomotion onset and that controls the initiation and velocity of locomotion as well as the entrainment of theta oscillations. Moreover, via septo-hippocampal projections onto alveus/oriens interneurons, this circuit regulates feedforward inhibition of Schaffer collateral and perforant path input to CA1 pyramidal neurons in a locomotion-dependent manner. With higher locomotion speed, the increased activity of medial septal VGluT2 neurons is translated into increased axo-somatic depolarization and higher firing rates of CA1 pyramidal neurons.