Patterns and plasticity of dental afferent inputs to trigeminal (V) brainstem neurons in kittens.
Patterns and plasticity of dental afferent inputs to trigeminal (V) brainstem neurons in kittens.
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发表时间：
1992
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通讯作者：
J. Hu;E. Shohara;B. Sessle
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作者：
J. Hu;E. Shohara;B. Sessle
在幼猫中，乳牙自然替换为恒牙列可能伴随着广泛的周围神经变性和神经再支配。由于我们以前曾报道过牙髓传入神经阻滞对V脑干神经元的重要生理影响，我们希望确定与乳牙脱落相关的传入神经阻滞是否伴随着小猫脑干中的神经可塑性变化。我们已经研究了牙髓传入终止模式在脑干以及V脑干神经元的电生理特性，在这种自然发生的deafferentation现象。幼猫脑干V亚核不同部位的HRP标记终末与成年猫相似。标记终末密度最高的是口亚核。口腔亚核神经元的特性也显示出3-4个月大的小猫和成年猫之间的许多相似之处，例如，(1)在1-4个牙齿（下颌和上颌犬齿和前磨牙）的触觉刺激激活的神经元的比例中，（2）对牙齿触觉刺激显示快适应或慢适应反应的神经元的比例，（3）1-4个牙齿的牙髓电刺激激活的神经元的比例，和（4）牙髓诱发反应的最小延迟。然而，牙髓输入的发生率，以及由牙周刺激和牙髓电刺激诱发的传入输入口肌神经元的会聚模式是不常见的小猫比成年猫。
In the young cat, the natural replacement of deciduous teeth with a permanent dentition may be accompanied by extensive peripheral nerve degeneration and reinnervation. Since we have previously reported significant physiological effects of tooth pulp deafferentation on V brainstem neurons, we wished to determine if deafferentation associated with deciduous tooth exfoliation was accompanied by comparable neuroplastic changes in the brainstem of kittens. We have examined the pulpal afferent terminating pattern within the brainstem as well as the electrophysiological properties of V brainstem neurons during this naturally occurring deafferentation phenomenon. The pattern of the HRP-labelled terminals in different parts of V brainstem subnuclei in kittens was similar to that in adult cats. The highest density of labelled terminals was found in the subnucleus oralis. The properties of subnucleus oralis neurons also showed many similarities between kittens at age of 3-4 months old and adult cats, e.g., (1) in the proportions of neurons activated by tactile stimulation of 1-4 teeth (mandibular and maxillary canines and premolars), (2) the ratio of neurons showing fast adapting or slow adapting responses to dental tactile stimulation, (3) the proportions of neurons activated by electrical pulp stimulation of 1-4 teeth, and (4) the minimal latencies of pulp-evoked responses. However, the incidences of pulpal inputs as well as the convergent pattern to oralis neurons of afferent inputs evoked by periodontal stimulation and electrical pulpal stimulation were less common in kittens than adult cats.