Retrograde tracing study on neurons labeled by injecting rear-thigh muscles with DiI in mice / 第三军医大学学报

ABSTRACT

Objective To explore the fluorescent distribution, and the relation between fluorescent intensity and time after injecting rear-thigh muscles with DiI. Methods Sixty-five new born mice were equally and randomly divided into 13 groups. Fluorescent distribution and intensity were investigated at 2, 4, 6, 8, 12, 24 h, and 2, 4, 7, 14, 28 d and 2, 3 months after injecting the left posterior limb rear thigh muscles with 1.5 ?l 4 mg/ml DiI for one mouse. Results The labeling neurons were scattered from L2 level to S2 level and associated dorsal root ganglion (DRG), but the most were located at L4 to L6 section. The faint red fluorescence neurons were observed at dorsal root ganglion and cornu anterius medullae spinalis 6 h post-injection. The labeling neurons increased up to the 4th day. The fluorescent intensity enhanced gradually from 6 h to 24 h, then kept the intensity for 3 months. Conclusion It is a quick, precise, persistent method to trance and label the dorsal root ganglions sensory neuron and spinal motoneuron by injecting rear-thigh muscles with DiI, and the rate of labeling neurons can be improved by prolonging the tracing time properly. It is also provide basic data for clinical or experimental neuron label and location.