Use of lectins as transganglionic neuronal tracers in the study of unmyelinated primary sensory neurons

One of the major advances in neurobiology in the last two decades has been the development of neural tracing techniques that allow the investigator to unequivocally establish the precise pattern of connections between different populations of neurons. Early neuronal tracers were relatively nonspecific agents transported by all neurons at the injection site. More recently however, the affinity of plant lectins for the membrane-associated glycoconjugates expressed by neurons has been utilized to develop a class of neuronal tracers that are taken up and transported by specific populations of neurons. The effectiveness of plant lectins as neuronal tracers is dependent on the distribution of the membrane-associated glycoconjugates to which they bind If the glycoconjugate to which the lectin binds is present on the majority of neurons, then this lectin will be suitable for use throughout the nervous system. However if the lectin binds to a relatively discrete group of neurons, it may be used to examine the connections of this specific population of neurons.