大鼠延髓背角和脊髓背角内PKCγ阳性神经元向中缝隐核的投射

PKCγ-IMMUNOREACTIVE NEURONS IN THE MEDULLARY AND SPINAL DORSAL HORNS PROJECTING TO THE NUCLEUS RAPHE OBSCURUS IN RAT

目的研究大鼠延髓背角和脊髓背角浅层内蛋白激酶Cγ亚单位（PKCγ）阳性神经元向中缝隐核（NRO）的投射。方法应用荧光金（FG）逆行追踪和PKCγ免疫荧光组织化学染色相结合的双标记方法,观察大鼠延髓背角和脊髓背角内PKCγ阳性神经元向中缝隐核的投射。结果将FG注入NRO,在延髓背角和脊髓背角的Ⅰ-Ⅲ层内可见FG逆标神经元;PKCγ阳性神经元主要分布于延髓背角和脊髓背角的Ⅱ层内侧部及Ⅱ、Ⅲ层交界处,Ⅰ、Ⅲ层内较少;延髓背角Ⅰ层和脊髓背角Ⅰ-Ⅲ层可观察到FG逆标并呈PKCγ阳性的双标神经元。结论延髓背角和脊髓背角浅层向NRO投射的神经元为PKCγ阳性神经元,其在向NRO传递信息的通路中可能发挥重要作用。

Objective To investigate the projections of protein kinase Cγ isoform （PKCγ） immunoreactive neurons from the medullary and spinal dorsal horns to the nucleus raphe obscurus （NRO） in rat. Methods The double labeling method of fluoro-gold （FG） retrograde tracing combined with immunofluorescence histochemica] staining was used. Results After injecting FG into the NRO, FG retrogradely labeled neurons were found in laminae Ⅰ-Ⅲ of the medullary and spinal dorsal horns. PKCγ immunoreactive neurons were mainly observed in the inner part of lamina H and the border region between laminae Ⅱ and Ⅲ , while in laminae Ⅰ and Ⅱ ,only a few PKCγ immunoreactive neurons were observed. Some FG-labeled neurons in lamina Ⅰ of the medul lary and laminae Ⅰ-Ⅲ of the spinal dorsal horn also exhibited PKCγ immunoreactivity. Conclusion The present results indicate that PKCγ containing neurons in the medullary and spinal dorsal horns project to the NRO,suggesting that PKCγ might be involved in the transmission of nociceptive information from the medullary and spinal dorsal horns to the NRO.