A role for T-type Ca2+ channels in mechanosensation

Primary afferent sensory neurons were amongst the first neuronal cell types to be studied for the expression of low-voltage-activated Ca2+ currents. Many early studies took advantage of the fact that these neurons are relatively easy to isolate and record from, and much of the initial biophysical data on T-type Ca2+ channels came from cultured sensory neurons [1], [2], [3], [4] and [5]. Shortly after this current had been described in sensory neurons, it was realized that the expression of T-type current is not constant across the DRG but appears to differ amongst subsets of sensory neuron [6]. It was suggested that these channels might contribute to particular sensations transmitted by individual neurons and this has recently been put to the test using pharmacological and genetic experiments in animal models of pain and mechanosensation.