The role of cerebro-ponto-cerebellar pathways in the control of vergence eye movements.
Single-unit recording and anatomical techniques have been used in Rhesus monkeys to investigate the central pathways involved in the neural control of vergence and ocular accommodation. Anatomical studies have revealed connections between the midbrain near-response region and the posterior interposed (IP) and fastigial nuclei of the cerebellum. Single-unit recording studies in the IP of alert, trained monkeys identified cells with activity that increased with increases in the amplitude of divergence and far accommodation, i.e. the far-response. Microstimulation at the site of these neurons often produced a far-response. Single-unit recording from a precerebellar nucleus, the nucleus reticularis tegmenti pontis (NRTP), identified some cells with activity that linearly increased with increases in the amplitude of the near-response, and some with activity that linearly increased with increases in the amplitude of the far-response. Microstimulation at the site of these near- or far-response neurons often produced changes in vergence angle and accommodation. Single-unit recording studies in the region of the frontal eye fields identified cells in the prearcuate cortex with activity that is modulated by either the near- or far-response. These results suggest that regions of the prearcuate cortex, the NRTP and the IP form part of a cerebro-ponto-cerebellar pathway modulating or controlling vergence and ocular accommodation.
Gamlin
P D
PD
Vision Science Research Center, University of Alabama at Birmingham 35294, USA.
Yoon
K
K
Zhang
H
H
D000065:Accommodation, Ocular / Q000502:physiology; D000818:Animals; D002531:Cerebellum / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology*; D008253:Macaca mulatta; D011149:Pons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*