Effects of neonatal undernutrition and binaural ear occlusion on neuronal development of the superior olivary complex of rats

Golgi-Cox-impregnated neurons of the superior olivary complex were investig ated in control, binaural ear-occluded control, undernourished, and binaura l ear-occluded undernourished Wistar rats of 12, 20, and 30 days of age. In neonatally undernourished and binaural ear-occluded animals, a significant reduction in the number of dendrites and dendritic intersections in the me dial trapezoid body neurons was observed. Inconsistent effects upon the den dritic arbor lateral superior olivary cells were also detected. Control and undernourished rats with binaural ear occlusion exhibited a significant in crease in the dendritic arbor measurements of lateral superior olivary neur ons as compared with the cells of the medial trapezoid body. The cytoarchit ectonic imbalance between the modulatory efferent control of these systems and the sensory auditory input to the cochlea may be important for the inte gration of complex auditory physiological phenomena.