Figure 3.

Example of a COOL neuron in the C7 segment with an axon that projected to contralateral VPL. A, Schematic representation of dorsal view of the brain indicating locations of stimulating tracks. The low-threshold point was surrounded medially, laterally, and rostrally by tracks in which 500 μA current pulses did not antidromically activate this axon. B, Cross section showing the low-threshold point located in contralateral VPL. IC, Internal capsule; LD, laterodorsal thalamic nucleus; MD, mediodorsal thalamic nucleus. C, Recording site in the marginal zone of C7. D, Receptive field covered the entire ipsilateral forelimb. E, This cell responded to only high-intensity mechanical stimuli applied to its cutaneous receptive field. F, G, Innocuous cool, noxious cold, and heat stimulation elicit increased activity from this unit. H, Line graph shows the response of this unit to thermal stimuli across a range of temperatures.