大鼠臂旁核向丘脑腹后内侧核的投射

目的　观察参与内脏感觉信息传递的臂旁核是否向与躯体感觉信息传递有密切关系的丘脑腹后内侧核（ＶＰＭ）投射。　方法　四甲基罗达明（ＴＭＲ）或辣根过氧化物酶（ＨＲＰ）逆行追踪和生物素葡聚糖胺（ＢＤＡ）顺行追踪技术。　结果　将ＴＭＲ或ＨＲＰ注入一侧ＶＰＭ 后，ＴＭＲ或ＨＲＰ逆标神经元主要位于同侧臂旁外侧核、ＫＦ核和臂旁内侧核；对侧臂旁外侧核和臂旁内侧核内仅见少量ＴＭＲ或ＨＲＰ逆标神经元。将ＢＤＡ注入一侧臂旁核后，ＢＤＡ顺标纤维和终末主要见于双侧ＶＰＭ、丘脑腹后外侧核、丘脑胶状质核和丘脑后核，注射区同侧的ＢＤＡ顺标纤维和终末明显多于对侧。　结论　臂旁核不仅与内脏感觉信息的传递有关，而且与躯体感觉信息的传递可能也有密切关系，并可能在躯体伤害性信息的调控中发挥重要作用。

THE PROJECTIONS FROM THE PARABRACHIAL NUCLEI TO THE THALAMIC VENTRAL POSTEROMEDIAL NUCLEUS IN THE RAT

Objective To observe the projections from the parabrachial nuclei(PBN) which is closely related to visceral sensory information transmission to the thalamic ventral posteromedial nucleus(VPM) which is mainly involved in somatic sensory information transmission. Methods Tetramethyl rhodamine(TMR) or horseradish peroxidase(HRP)retrograde tracing and biotinylated dextran amine(BDA) anterograde tracing techniques were used. Results After injecting TMR or HRP into the unilateral VPM, TMR or HRP retrogradely labeled neuronal cell bodies were mainly found in the ipsilateral lateral parabrachial nucleus (PBL), Kolliker Fuse nucleus(KF) and medial parabrachial nucleus(PBM). In the contralateral PBL, KF and PBM, only a few TMR or HRP retrogradely labeled neurons were observed. After injecting BDA into the unilateral parabrachial nuclei, BDA anterogradely labeled fibers and terminals were mainly encountered bilaterally in the VPM, but with an ipsilateral predominance. BDA anterogradely labeled fibers and teminals were also found in the thalamic ventral posterolateral nucleus(VPL), thalamic posterior nucleus(PO) and submedius nucleus of the thalamus (SM) with an ipsilateral predominance. Conclusion PBN is not only a relay station for visceral sensory information transmission, but also closely related to somatic sensory information transmission.PBN might also play an important role in the regulation of somatic sensory information.