Also known as the dorsomedial group of the thalamus, the medial nuclear group consists of the magnocellular mediodorsal thalamus, parvocellular mediodorsal thalamus, and a lateral group that includes the densocellular, pars multiforms mediodorsal thalamic nuclei, and lateral MD. The largest of the nuclear structures in the medial thalamus, the medial dorsal nucleus forms reciprocal connections with the medial, lateral, and orbital prefrontal cortex. Most neurons that project to the medial dorsal nucleus originate from layers V and VI of the cortex. Glutamate is the main neurotransmitter. The amygdala also projects to the dorsomedial group. Overall, the region has a role in amnesia, memory, and other cognitive-relative behaviors.