Answer:
Central posterolateral thalamus.
Step-by-step explanation:
The third order neuron originates from Central posterolateral nuclei thalamus because it is the nucleus of thalamus because it receive impulses from the neospinothalamic tract and the medial lemniscus of the posterior column-medial lemniscus pathway i.e it received sensory information from the body, send it to the brain and then transfer the information to brodman.