The lower thalamic peduncle runs in the sublenticular part of the capsula interlenticula.
The lower thalamus peduncle consists of filamentous masses that connect the thalamus with parts of the orbitofrontal cortex, with the temporal cortex, with the insular cortex, with the basal forebrain and with the amygdala.
Filaments of the lower thalamic peduncle, together with filaments that connect the amygdala to the hypothalamus, form the so-called ansa peduncularis, which passes under, ventrally about, the lentiformis nucleus through the basal forebrain.