Neurotrophin-4 Modulates the Mechanotransducer Cav3.2 T-Type Calcium Current in Mice Down-Hair Neurons

The study demonstrated that neurotrophin-4 (NT-4) modulated the Cav3.2 T-type calcium current in mechanosensitive D-hair neurons in mice. Interruption of NT-4 supply via peripheral nerve axotomy led to a decrease in T-current amplitude, which was restored by NT-4 incubation. Genetic deletion of NT-4 also resulted in a loss of T-current, reversible by NT-4 addition. NT-4 did not affect T-current in Cav3.2-/- neurons, nor did it alter the biophysical properties or transcript expression of Cav3.2. The study identified the PI3K pathway, activated by the TrkB receptor, as crucial for T-current potentiation, highlighting NT-4's role in regulating mechanosensitive neuron function through post-transcriptional up-regulation of the Cav3.2 T-current.