치수통각 전도에서 삼차신경 척수감각핵의 역할 = Role of Trigeminal Spinal Sensory Nuclei on Neural Conduction of Dental Pain

다국어 초록 (Multilingual Abstract)

In spite of many recent studies, there remains a conflict on the relative contribution of caudal and rostral components of trigeminal sensory nuclei to V brainstem mechanism of orofacial nociception. This study was performed to clarify the properties of neurons in trigeminal sensory nuclei which are responsive to noxious electrical stimuli applied to tooth pulp and the role of caudal and rostral components of trigeminal sensory nuclei on the transmission of orofacial nociceptive information.
Adult cats are anesthetized with α-chloralose(60 ㎎/㎏), a pair of electrodes was inserted to anterior digastric muscle to record EMG evoked by noxious electric stimuli to tooth pulp and the animal was fixed to stereotaxic frame. An occipital craniotomy and cervical laminectomy were carried out to allow the introduction by a microdrive of glass-coated tungsten microelectrode for recording the extracellular activity of single units in trigeminal spinal sensory nuclei and then responses of neurons to noxious electrical stimuli applied to tooth were examined.
1. The EMG of anterior digastric muscle was response conducted through Aδ primary afferent from tooth pulp and EMG was not disappeared after trigeminal tractotomy at the level of obex.
2. Neural activities in trigeminal sensory nuclei were recorded at lateral 2.5∼5.5 ㎜ to obex. 1.5∼3.0 ㎜ below the bulbar surface and rostrocaudal 4∼-3 ㎜ obex.
3. Neural activities were not recorded in case that noxious electrical stimuli were applied to cotralateral tooth.
4. In rostral parts, neural activities were recorded at the neurons conducted through Aβ and Aδ primary afferent from ipsilateral tooth.
5. In rostral parts, neural activities were recorded at the neurons conducted through C primary afferent from ipsilateral tooth.
From these results, it is assumed that sensation other than pain mediated by Aβ-nerve fiber and sharp pain mediated by Aδ-nerve fiber are transmitted through rostral part of trigeminal sensory nuclei and dull pain mediated by C-nerve fiber is transmitted through caudal part of trigrmianl sensory nuclei.