sentences:  Neurons of this nucleus are pseudounipolar that receive proprioceptive information from the mandible and send projections to the trigeminal motor nucleus to mediate monosynaptic jaw jerk reflexes.The mesencephalic nucleus is the only structure in the central nervous system to contain the cell bodies of first order sensory neurons.The mesencephalic nucleus can thus be considered functionally as a sensory ganglion embedded within the brainstem, making it neuroanatomically unique .