Sánchez Eduardo, Barro Senén, Mariño Jorge, Canedo Antonio
Grupo de Sistemas Intelixentes, Departamento de Electrónica e Computación, Facultade de Físicas, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Spain.
Network. 2003 May;14(2):211-31.
The dorsal column nuclei, cuneatus and gracilis, play a fundamental role in the processing and integration of somesthetic ascending information. Intracellular and patch-clamp recordings obtained in cat in vivo have shown that cuneothalamic projection neurons present two modes of activity: oscillatory and tonic (Canedo et al 1998 Neuroscience 84 603-17). The former is the basis of generating, in sleep and anaesthetized states, slow, delta and spindle rhythms under the control of the cerebral cortex (Mariño et al 2000 Neuroscience 95 657-73). The latter is needed, during wakefulness, to process somesthetic information in real time. To study this behaviour we have developed the first realistic computational model of the cuneothalamic projection neurons. The modelling was guided by experimental recordings, which suggest the existence of hyperpolarization-activated inward currents, transient low- and high-threshold calcium currents, and calcium-activated potassium currents. The neuronal responses were simulated during (1) sleep, (2) transition from sleep to wakefulness and (3) wakefulness under both excitatory and inhibitory synaptic input. In wakefulness the model predicts a set of synaptically driven firing modes that could be associated with information processing strategies in the middle cuneate nucleus.
薄束核和楔束核在躯体感觉上行信息的处理和整合中发挥着重要作用。在猫体内进行的细胞内和膜片钳记录表明，楔丘脑投射神经元存在两种活动模式：振荡性和紧张性（卡内多等人，1998年，《神经科学》84卷，603 - 17页）。前者是在睡眠和麻醉状态下，在大脑皮层控制下产生缓慢的δ波和纺锤波节律的基础（马里尼奥等人，2000年，《神经科学》95卷，657 - 73页）。后者在清醒时用于实时处理躯体感觉信息。为了研究这种行为，我们开发了首个楔丘脑投射神经元的真实计算模型。该建模以实验记录为指导，实验记录表明存在超极化激活内向电流、瞬态低阈值和高阈值钙电流以及钙激活钾电流。在（1）睡眠、（2）从睡眠到清醒的过渡以及（3）清醒状态下，在兴奋性和抑制性突触输入的情况下模拟了神经元反应。在清醒状态下，该模型预测了一组可能与楔束核中部信息处理策略相关的突触驱动放电模式。
