CROSS-MODAL NEUROPLASTICITY IN THE BLIND MOLE-RAT SPALAX-EHRENBERGI -A WGA-HRP TRACING STUDY

SPALAX ehrenbergi is a subterranean rodent possessing extremely degene rated eyes but a distinguishable dorsal lateral geniculate nucleus (dL GN) which projects ipsilaterally to a fair sized striate cortex. 2-Deo xyglucose and electrophysiological studies have shown that these areas are vigorously activated by auditory input, We show here, using the n euroanatomical tracer WGA-HRP, that the major source of the auditory i nput to the visual system is the inferior colliculus that, in addition to all its typical auditory targets, also projects to the dLGN. The v isual thalamo-cortical pathway thereupon processes auditory informatio n. This is the first naturally blind mammal in which the origin of aud itory compensatory projections have been traced and described.