Intracortical microstimulation can be used successfully to modulate neuronal activity. Activity-dependent stimulation (ADS), in which action potentials recorded extracellularly from a single neuron are used to trigger stimulation at another cortical location (closed-loop), is an effective treatment for behavioral recovery after brain lesion, but the related neurophysiological changes are still not clear. Here, we investigated the ability of ADS and random stimulation (RS) to alter firing patterns of distant cortical locations. We recorded 591 neuronal units from 23 Long-Evan healthy anesthetized rats. Stimulation was delivered to either forelimb or barrel field somatosensory cortex, using either RS or ADS triggered from spikes recorded in the rostral forelimb area (RFA). Both RS and ADS stimulation protocols rapidly altered spike firing within RFA compared with no stimulation. We observed increase in firing rates and change of spike patterns. ADS was more effective than RS in increasing evoked spikes during the stimulation periods, by producing a reliable, progressive increase in stimulus-related activity over time and an increased coupling of the trigger channel with the network. These results are critical for understanding the efficacy of closed-loop electrical microstimulation protocols in altering activity patterns in interconnected brain networks, thus modulating cortical state and functional connectivity.

中文翻译：

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开环和闭环皮层内微刺激对远皮层区域神经元放电模式的不同影响。

皮质内微刺激可成功用于调节神经元活动。活动依赖性刺激 (ADS)，其中从单个神经元细胞外记录的动作电位用于触发另一个皮层位置的刺激（闭环），是脑损伤后行为恢复的有效治疗方法，但相关的神经生理变化是还是不清楚。在这里，我们研究了 ADS 和随机刺激 (RS) 改变远处皮质位置的放电模式的能力。我们记录了 23 只 Long-Evan 健康麻醉大鼠的 591 个神经元单位。使用 RS 或 ADS 将刺激传递到前肢或桶状场体感皮层，该信号由前肢前肢区域 (RFA) 中记录的尖峰触发。与没有刺激相比，RS 和 ADS 刺激方案都迅速改变了 RFA 内的尖峰激发。我们观察到发射率的增加和尖峰模式的变化。ADS 在刺激期间通过产生可靠的、渐进的刺激相关活动增加以及触发通道与网络的耦合增加，在增加刺激期间的诱发尖峰方面比 RS 更有效。这些结果对于理解闭环电微刺激协议在改变互连大脑网络中的活动模式方面的功效至关重要，从而调节皮质状态和功能连接。随着时间的推移，刺激相关活动的可靠、渐进增加以及触发通道与网络的耦合增加。这些结果对于理解闭环电微刺激协议在改变互连大脑网络中的活动模式方面的功效至关重要，从而调节皮质状态和功能连接。随着时间的推移，刺激相关活动的可靠、渐进增加以及触发通道与网络的耦合增加。这些结果对于理解闭环电微刺激协议在改变互连大脑网络中的活动模式方面的功效至关重要，从而调节皮质状态和功能连接。