McCarthy G, Allison T
Neuropsychology Laboratory, Veterans Administration Medical Center, West Haven, Connecticut, USA.
J Neurosurg. 1995 Jun;82(6):1015-20. doi: 10.3171/jns.1995.82.6.1015.
Somatosensory evoked potentials (SEPs) obtained in response to stimulation of the median nerve, posterior tibial nerve, lips, tongue, palate, and pharynx were recorded in four monkeys (Macaca mulatta) under light barbiturate anesthesia. In agreement with the results of SEP recordings in humans and single-unit recordings in monkeys, there is a medial-to-lateral representation in somatosensory cortex of the hand, lips, and tongue. There is a discontinuity in the representation of the upper mouth: the tongue representation is interposed between a medial region (near the lip representation), usually representing the lateral hard palate and gum, and a lateral region (near the lateral sulcus), usually representing the central hard palate. For all types of trigeminal stimulation, root mean square (RMS) voltage maps show maxima over somatosensory cortex. Laminar recordings demonstrated that trigeminal SEPs recorded from the cortical surface are generated in somatosensory cortex in areas 1, 2, and 3b. Median nerve and posterior tibial nerve stimulation did not evoke SEPs in the surface cortex near the lateral sulcus, suggesting that the most lateral portion of the postcentral gyrus is not a part of the second somatosensory area (SII). This lateral region may contain the representation of posterior intraoral structures, but it was not possible to confirm this assumption by stimulation of the soft palate or pharynx.
在轻度巴比妥类麻醉下，对4只恒河猴（猕猴）记录了由正中神经、胫后神经、嘴唇、舌头、腭和咽部刺激所诱发的体感诱发电位（SEP）。与人类SEP记录结果和猴子单单位记录结果一致，在体感皮层中，手、嘴唇和舌头存在从内侧到外侧的代表区。在上颌的代表区存在不连续性：舌头的代表区介于内侧区域（靠近嘴唇代表区）和外侧区域（靠近外侧沟）之间，内侧区域通常代表外侧硬腭和牙龈，外侧区域通常代表中央硬腭。对于所有类型的三叉神经刺激，均方根（RMS）电压图显示在体感皮层上有最大值。分层记录表明，从皮层表面记录到的三叉神经SEP是在体感皮层的1区、2区和3b区产生的。正中神经和胫后神经刺激未在外侧沟附近的表面皮层诱发SEP，这表明中央后回的最外侧部分不是第二体感区（SII）的一部分。这个外侧区域可能包含口腔后部结构的代表区，但通过刺激软腭或咽部无法证实这一假设。
