Department of Physical Therapy, Western University of Health Sciences, Pomona, CA, USA.
Eur J Neurosci. 2010 Oct;32(8):1354-63. doi: 10.1111/j.1460-9568.2010.07396.x. Epub 2010 Sep 16.
The mouse trigeminal (V) system undergoes significant postnatal structural and functional developmental changes. Histological modules (barrelettes, barreloids and barrels) in the brainstem, thalamus and cortex related to actively moved (whisking) tactile hairs (vibrissae) on the face allow detailed studies of development. High-resolution [(3) H]2-deoxyglucose (2DG) emulsion autoradiography with cytochrome oxidase histochemistry was used to analyze neuronal activity changes related to specific whisker modules in the developing and mature mouse V system provoked by passive (experimenter-induced) and active (animal-induced) displacements of a single whisker (D4). We tested the hypothesis that neuronal activity patterns change in relation to the onset of active touch (whisking) on postnatal day (P)14. Quantitative image analyses revealed: (i) on P7, when whisker-like patterns of modules are clear, heightened 2DG activity in all appropriate modules in the brainstem, thalamus and cortex; (ii) on P14, a transitory activity pattern coincident with the emergence of whisking behavior that presages (iii) strong labeling of the spinal V subnucleus interpolaris and barrel cortex produced by single-whisker-mediated active touch in adults and (iv) at all above-listed ages and structures, significant suppression of baseline activity in some modules surrounding those representing the stimulated whisker. Differences in activity patterns before and after the onset of whisking behavior may be caused by neuronal activity induced by whisking, and by strengthening of modulatory projections that alter the activity of subcortical inputs produced by whisking behavior during active touch.
小鼠的三叉神经（V）系统在出生后经历了显著的结构和功能发育变化。与面部主动移动（刷动）触觉毛发（触须）相关的脑干、丘脑和皮层中的组织学模块（棒状体、棒状体和桶状结构）允许对发育进行详细研究。使用高分辨率[3H]2-脱氧葡萄糖（2DG）乳剂放射自显影结合细胞色素氧化酶组织化学来分析与发育中和成熟的小鼠 V 系统中的特定触须模块相关的神经元活动变化，这些变化是由单个触须（D4）的被动（实验者诱导）和主动（动物诱导）位移引起的。我们假设，在出生后第 14 天（P14），当出现主动触觉（刷动）时，神经元活动模式会发生变化。定量图像分析显示：（i）在 P7 时，当模块的触须样模式清晰时，脑干、丘脑和皮层中所有适当模块的 2DG 活性升高；（ii）在 P14 时，与刷动行为出现一致的短暂活动模式，预示着（iii）成年动物通过单触须介导的主动触觉引起的脊髓 V 间核和桶状皮层的强烈标记；以及（iv）在上述所有年龄和结构中，刺激触须周围的一些模块的基线活性显著抑制。在刷动行为开始前后的活动模式差异可能是由刷动引起的神经元活动和改变由刷动行为产生的亚皮质输入活动的调制投射的增强引起的。
