动物脑中的听觉核团是由中心的核区和包裹在其外周的壳区组成，而丘脑中的体感觉核团也有相似的结构。研究表明脊椎动物脑中听觉核团的核区神经元的出现要晚于壳区的神经元，为了验证在体感觉核团中是否也有这个规律，本实验对怀孕8到19天的母鼠进行了3H-T注射标记,所有的胚胎鼠出生后30天处死。放射自显影的结果显示，壳区的Rt核团最早开始发育;壳区的PO核团与核区的VP核团虽然同时开始发育并同时达到高峰期，但PO在12天的发育比VP活跃，而在第13天的发育不如VP活跃。本实验初步验证了哺乳类体感觉核团中核区神经元的出现要晚于壳区神经元这个规律，但需要进一步的数据支持。

Auditory nuclei in the brain of vertebrate animals are composed of a core and a surrounding portion,named “matrix”.A similar.structure is found in the somatosensory nuclei in the thalamus. It has been shown that neurons in the core are born later than those in its surrounding areas in auditory nuclei, but whether the somatosensory nuclei share the same neurogenetic pattern is stiil unknown. To address this issue, we injected a series of small doses of 3H-thymidine into pregnant mice (from embryonic day 8 to 19). All the mice were killed at post hatching 30 days. The 3H-thymidine autoradiographical results indicate that neurogenesis within the Rt nucleus (matrix)is earliest.Neurons in PO (matrix)and VP(core) are generated at the same time (E12-E13). However, PO has higher rate of H3-marked-neuron than VP　at the first day of generation,while next day (peak)VP has a higher rate than PO. This research primarily demonstrates that matrix nuclei are born later than core nuclei in somatosensory thalamus of mammais, but additional data is needed to strengthen the conclusion.