Differential expression of voltage-gated potassium channel genes in auditory nuclei of the mouse brainstem.

Voltage-gated potassium (Kv) channels may play an important role in the encoding of auditory information. Towards understanding the roles of Shaker and Shaw-like channels in this process, we examine here the expression of Kv1.1, Kv1.2, Kv3.1, and Kv3.3 in the central auditory nuclei of the mouse using quantitative in situ hybridization techniques. We establish rank order for each channel's expression in each region, finding that the medial nucleus of the trapezoid body shows the highest signal for each of the four channel genes. In other auditory nuclei differential expression is found among and between members of both Shaker and Shaw subfamilies. Of particular interest is the stark contrast between high level expression of Kv1.1 and very low level expression of Kv3.1 in the octopus cell area of the cochlear nucleus and in the lateral superior olivary nucleus. These unique expression patterns suggest that Kv channel gene expression is regulated to allow brainstem auditory neurons to transmit temporally patterned signals with high fidelity. In instances where specific cell types can be tentatively identified, we discuss the possible contribution made by these channel genes to the physiological properties of those neurons.