the small region of the ventral posteromedial nucleus of thalamus in which the fibers of the gustatory lemniscus and secondary trigeminal tracts terminate; it projects to the lower part of the postcentral gyrus of the cerebral cortex. SYN: arcuate nucleus (1) [TA], nucleus arcuatus thalami, semilunar nucleus of Flechsig, thalamic gustatory nucleus.