It relays sensory information from the second-order neurons of the neospinothalamic tract and medial lemniscus (of the posterior column-medial lemniscus pathway) which synapse with in the third-order neurons in the nucleus.
It relays sensory data from higher-order neurons in the posterior column-medial lemniscus pathway to lower-order neurons in the nucleus, forming a connection between these two groups of neurons.