Tetrode Layout
Hardware
Four recording sites placed close together as one group, so a single neuron reaches all four and can be separated by the amplitude pattern across them.
A cluster of four sites. Because the group is small relative to the reach of one neuron's field, a unit near the shank appears on all four at different amplitudes. That ratio is close to unique to the neuron's position, which is what gives the layout its high-quality cell discrimination.
A design may carry several groups spaced along the shank, each resolving units at its own depth with gaps between them. The Q-Trode line is the dedicated single-group product — one four-site cluster on one shank.
In a model number the layout field reads tet.