Retrograde Tracing Technique

Synonyms

Retrograde Labeling

Definition

Retrograde tracing (retrograde labeling) is a neuroanatomical method used to determine the location of the cells of origin of a nervous system pathway. A tracer substance that will be taken up by synaptic terminals (and sometimes by axons) is injected into a region of interest, such as a central nervous system nucleus. The tracer is then conveyed retrogradely by axonal transport to the cell bodies, and often just the proximal dendrites of the neurons that give rise to the projection being labeled. After a suitable time has passed to allow for the uptake and transport of the tracer, the nervous tissue is fixed, sectioned and the retrograde tracer located microscopically. In some cases, histological processing is required to visualize the tracer. In other cases, the tracer is fluorescent and can be identified using suitable optics without special processing.

Spinohypothalamic Tract, Anatomical Organization and Response Properties

Spinothalamic...