Dendritic discrimination of temporal input sequences in cortical neurons
Dendritic discrimination of temporal input sequences in cortical neurons
Branco T, Clark BA, Häusser M.
Science. 2010 Sep 24;329(5999):1671-5. Epub 2010 Aug 12.
The detection and discrimination of temporal sequences is fundamental to brain function and underlies perception, cognition, and motor output. By applying patterned, two-photon glutamate uncaging, we found that single dendrites of cortical pyramidal neurons exhibit sensitivity to the sequence of synaptic activation. This sensitivity is encoded by both local dendritic calcium signals and somatic depolarization, leading to sequence-selective spike output. The mechanism involves dendritic impedance gradients and nonlinear synaptic N-methyl-D-aspartate receptor activation and is generalizable to dendrites in different neuronal types. This enables discrimination of patterns delivered to a single dendrite, as well as patterns distributed randomly across the dendritic tree. Pyramidal cell dendrites can thus act as processing compartments for the detection of synaptic sequences, thereby implementing a fundamental cortical computation.
- 2-photon un-caging, acute brain study.
- single dendriteにおいて,シナプス入力が"末端→細胞体方向"に入力される場合と"細胞体→末端方向"に入力される場合では,異なる時間加算性を持つ.
- さらに非線形応答を示す.(どちらの方向でもsupralinear.しかし"末端→細胞体"方向の方が大きい)
- この非線形性はAP5存在下では消失.(NMDAチャネル依存の可能性)
