Recently it was supposed by many researchers that posterior group of nuclei in thalamus(PO)took important role in reception of pain sensation. However

there were some controversy among researchers over topograghy

classification and function of the subnuclei in PO. In this reriew

topography of the PO

the connection of PO with somatic and visceral afferent nerve fibers

the connection of PO with cortex

especially the secondary sensory area and the characteristics of noxious neurons in PO were summarized. All in all

PO in thalamus was referred to as important integrative cen- ter of pain sensation.