Studies on The Response and Morphology of The Cortical Neurons using Double Intracellular labeling

本研究旨在用逆行或顺行追踪技术结合细胞内染色来揭示神经元的形态。这些实验是在老鼠、猫和猴子身上进行的。在戊巴比妥钠麻醉下(30 mg/kg，ip)，在大脑皮层、丘脑和小脑深核的某些区域注射了几种荧光染料。存活1~2周后，分别用相同剂量的戊巴比妥钠或2g/kg的乌拉坦进行急性实验。用填充5%HRP、2.5%生物细胞素或20%荧光黄的玻璃微电极对大脑皮质或丘脑神经元进行细胞内记录。用细胞内染色对猫体感觉皮质的研究可以揭示丘脑对锥体神经元的激活方式，并发表在(Exp.大脑研究，80，‘90)。来自大鼠皮质神经元的数据需要更多的样本记录，但已有初步报道出现在会议录(Yamamoto et al.，‘90，’91)中，报道了皮层神经元的放电特性与形态特征之间的关系。关于小脑-丘脑的投射，我们可以报告丘脑的皮质层分布。丘脑VL神经元的纤维和放电特性(Neurosci.研究结果，9，‘90；经验大脑研究，87，‘91)。关于猴的小脑-丘脑投射，我们尝试用双束标记法显示小脑-前额叶反应的丘脑中继核，可以清楚地表明，背内侧核是小脑-前额叶投射的丘脑中继核之一，该结果将于1992年发表在《脑研究》杂志上。在进一步的实验中，我们将尝试测试荧光染料和胞内染色染料的合适组合。

The present study is aimed to reveal the neuronal morphology using the retrograde or anterograde tract tracing techniques combined with intracellular staining. The experiments were performed on rats, cats and monkeys. Under pentobarbital anesthesia(30mg/kg, i. p.), several fluorescent dyes were injected into certain areas in the cerebral cortex, thalamus and deep cerebellar nuclei. After 1-2 weeks survival, animals were reanesthetized with pentobarbital(same dose)or urethane(2g/kg, i. p.)for acute experiments. Intracellular recordings were done from neurons in the cortex or the thalamus with glass microelectrodes filled with 5% HRP, 2.5% biocytin or 20% Lucifer yellow. The studies on the cat somatosensory cortex using intracellular staining could reveal the mode of the thalamic activation onto the pyramidal neurons and were published in the journal (Exp. Brain Res., 80, '90). The data from rat cortical neurons need more sample records, but preliminary reports have been appeared in the proceedings (Yamamoto et al., '90, '91), which reported the relationship between the firing properties and the morphological features of the cortical neurons. Concerning the cerebello-thalamic projection, we could report the cortical laminar distribution of the thalamic. fibers as well as firing properties of the thalamic VL neurons (Neurosci. Res., 9, '90 ; Exp. Brain Res., 87, '91). Concerning the monkey cerebello-thalamic projection, we tried double tract labeling method to demonstrate the thalamic relays of the cerebello-prefrontal responses, and we could clearly show that the mediodorsal nucleus is one of the thalamic relay nuclei of the cerebello-prefrontal projection, which will be published in the Brain Research in 1992. In the further experiments, we will try to test suitable combination of the fluorescent dyes and intracellular staining dyes.