The parafascicular nucleus of thalamus exhibits convergence input from the dorsal raphe and the spinal tract of the trigeminal nerve.

Single unit activity was recorded in 92 units in the parafascicular nucleus (PFN) of the rat. Stimulation electrodes were placed in the dorsal raphe (DR) and spinal tract of the trigeminal nerve (SpV). Stimulation of either the DR or SpV evoked significant changes in firing rates of PFN units. Some units responded with short latency driven activity. Driven and non-driven convergence of input was detected. These findings support the concept that the PFN may be a site of modulation of analgesia and pain appreciation.