NADPH-diaphorase activity in the central auditory structures of the rat

Distribution of NADPH-diaphorase (NADPH-d) positive neurones was investigated in the central auditory structures of the rat. NADPH-d positive perikarya were found in the dorsal and external cortices of the inferior colliculus and in the intercollicular commissure. Within the medial geniculate body (MGB), stained cell bodies were observed in the dorsal part of the suprageniculate nucleus and in the basal part of the medial division of the MGB. Occurrence of the NADPH-d positive perikarya in the MGB is limited to its caudal third. NADPH-d positive cells are dispersed in the auditory temporal cortex within layers II-VI, with a slight prevalence in the infragranular layers. NADPH-d positive neurones have smooth dendrites without stained dendritic spines.