High channel count electrode system to investigate thalamocortical interactions.

A novel silicon-based microelectrode array with one- and two-dimensional variants was developed in the framework of the EU-funded research project NeuroProbes. The electrode array comprises complementary-metal-oxide-semiconductor based integrated circuitry to implement the concept of electronic depth control which is used to select up to 32 recording sites from more than 1000 possible electrode channels integrated on four slender probe shafts. The electrode array was tested in acute experiments performed simultaneously in cortex and thalamus of the rat brain. In both brain regions good quality local field potential and multiunit activity was recorded during the tests.