Localization of dura-sensitive (red stars) and dura-insensitive (blue stars) neurons in the thalamus. A, Localization of the cell bodies in the VPM, Po, and LD and LP nuclei (each nucleus highlighted in yellow). Numbers in red indicate the coronal plane (millimeters from bregma) according to the rat brain atlas (Paxinos and Watson, 1998). B, A photomicrograph of the cell body and dendritic tree of a dura-sensitive (LP) neuron that was labeled with the anterograde tracer TMR-dextran. Uptake of the tracer by the target cell body was achieved by inducing bouts of neuronal firing (red trace) in response to repetitive electrical pulses (blue trace) delivered from the recording micropipette, which was preloaded with the tracer. APT, Anterior pretectal nucleus; DLG, dorsal lateral geniculate nucleus; LDDM, laterodorsal thalamic nucleus, dorsomedial; LDVL, laterodorsal thalamic nucleus, ventrolateral; LPMR, lateral posterior thalamic nucleus, mediorostral; Po, posterior thalamic nuclear group; Rt, reticular thalamic nucleus; VPL, ventral posterolateral thalamic nucleus; VPM, ventral posteromedial thalamic nucleus.