Concanavalin A: a tool to investigate neuronal plasticity

Neuronal plasticity is the ability of neurons to alter their cellular properties in response to changes in their environment. These changes are typically triggered by the binding of specific ligands, such as neurotransmitters, growth factors or other neuromodulators, to receptors on the neuronal membrane surface. Since the extracellular domains of many of these receptors are glycosylated, they can also be bound by lectins--proteins with high affinity binding sites for polysaccharides. Different lectins have different affinities for various sugar residues. This feature has made lectins useful in the investigation of the regional localization and relative mobility of different classes of glycosylated membrane receptors, and in the subsequent purification of the receptors. This article reviews some of the different kinds of neuronal plasticity produced by the plant lectin concanavalin A (Con A), such as enhancement of neurite outgrowth, modulation of neurotransmitter responses, and alteration in the specificity and strength of synaptic connections.