Histocytochemical Pattern of Enzyme Distribution in Cochlea of the Kangaroo Rat (D. Spectabilis) at Rest and Following Auditory Stimulation

Abstract

The histocytochemical distribution of enzymes in the cochlea of the kangaroo rat, Dipodomys spectabilis, at rest and following auditory stimulation was investigated. At rest, enzyme distribution in D. Apectabilis resembles that previously reported by Webster & Stack (1966, 1968) in D. merriami. Krebs cycle enzymes are prominent in the sensory epithelium, stria vascularis, spiral ligament, and external spiral sulcus. The spatial pattern of general esterase activity is also similar. No increase or decrease of either succinic dehydrogenase or carboxylic esterase activity, as measured by a microscopically visible quantitative change in deposition product, is observed following acoustic stimulation. Injury to the basal and second turns, however, is seen in a few cochleae. The validity of using histochemical methods for the demonstration of fluctuation in enzyme activity is discussed.