PDF(Pubmed)
Abstract：
UNASSIGNED: Complex neuronal interactions underlie cortical information processing that can be compromised in altered states of consciousness. Here intracortical microstimulation was applied to investigate anesthetic state-dependent effective connectivity of neurons in rat visual cortex in vivo.
UNASSIGNED: Extracellular activity was recorded at 32 sites in layers 5/6 while stimulating with charge-balanced discrete pulses at each electrode in random order. The same stimulation pattern was applied at three levels of anesthesia with desflurane and in wakefulness. Spikes were sorted and classified by their waveform features as putative excitatory and inhibitory neurons. Network motifs were identified in graphs of effective connectivity constructed from monosynaptic cross-correlograms.
UNASSIGNED: Microstimulation caused early (<10 ms) increase followed by prolonged (11-100 ms) decrease in spiking of all neurons throughout the electrode array. The early response of excitatory but not inhibitory neurons decayed rapidly with distance from the stimulation site over 1 mm. Effective connectivity of neurons with significant stimulus response was dense in wakefulness and sparse under anesthesia. The number of network motifs, especially those of higher order, increased rapidly as the anesthesia was withdrawn indicating a substantial increase in network connectivity as the animals woke up.
UNASSIGNED: The results illuminate the impact of anesthesia on functional integrity of local cortical circuits affecting the state of consciousness.
UNASSIGNED: Extracellular activity was recorded at 32 sites in layers 5/6 while stimulating with charge-balanced discrete pulses at each electrode in random order. The same stimulation pattern was applied at three levels of anesthesia with desflurane and in wakefulness. Spikes were sorted and classified by their waveform features as putative excitatory and inhibitory neurons. Network motifs were identified in graphs of effective connectivity constructed from monosynaptic cross-correlograms.
UNASSIGNED: Microstimulation caused early (<10 ms) increase followed by prolonged (11-100 ms) decrease in spiking of all neurons throughout the electrode array. The early response of excitatory but not inhibitory neurons decayed rapidly with distance from the stimulation site over 1 mm. Effective connectivity of neurons with significant stimulus response was dense in wakefulness and sparse under anesthesia. The number of network motifs, especially those of higher order, increased rapidly as the anesthesia was withdrawn indicating a substantial increase in network connectivity as the animals woke up.
UNASSIGNED: The results illuminate the impact of anesthesia on functional integrity of local cortical circuits affecting the state of consciousness.
摘要：
■复杂的神经元相互作用是皮层信息处理的基础，在意识状态改变时可能会受到损害。在这里，皮质内微刺激用于研究大鼠视觉皮层中麻醉状态依赖性神经元的有效连接。
■在层5/6中的32个位点处记录细胞外活性,同时在每个电极处以随机顺序用电荷平衡的离散脉冲进行刺激。在地氟醚麻醉的三个水平和清醒状态下应用相同的刺激模式。将尖峰按其波形特征分类为假定的兴奋性和抑制性神经元。在从单突触交叉相关图构建的有效连通性图中识别出网络基序。
■微刺激引起早期（<10ms）增加，然后是整个电极阵列中所有神经元的尖峰延长（11-100ms）减少。兴奋性而非抑制性神经元的早期反应随着与刺激部位的距离超过1mm而迅速衰减。具有显著刺激反应的神经元的有效连接在清醒时密集，在麻醉下稀疏。网络图案的数量，尤其是那些更高级的，随着麻醉的退出而迅速增加，这表明当动物醒来时，网络连接性大幅增加。
■结果阐明了麻醉对影响意识状态的局部皮质回路功能完整性的影响。
■在层5/6中的32个位点处记录细胞外活性,同时在每个电极处以随机顺序用电荷平衡的离散脉冲进行刺激。在地氟醚麻醉的三个水平和清醒状态下应用相同的刺激模式。将尖峰按其波形特征分类为假定的兴奋性和抑制性神经元。在从单突触交叉相关图构建的有效连通性图中识别出网络基序。
■微刺激引起早期（<10ms）增加，然后是整个电极阵列中所有神经元的尖峰延长（11-100ms）减少。兴奋性而非抑制性神经元的早期反应随着与刺激部位的距离超过1mm而迅速衰减。具有显著刺激反应的神经元的有效连接在清醒时密集，在麻醉下稀疏。网络图案的数量，尤其是那些更高级的，随着麻醉的退出而迅速增加，这表明当动物醒来时，网络连接性大幅增加。
■结果阐明了麻醉对影响意识状态的局部皮质回路功能完整性的影响。
