EYE MOVEMENTSNBIO 401

Monday, November 22, 2010Ric Robinson

Objectives:-Be able to describe the neural pathway of the VOR, i.e., the pathway through which vestibular information contracts eye muscles. (labyrinth - vestibular nuclei -oculomotor neurons.)

-Be able to explain why the VOR is important to clear vision.

-Be able to explain how putting cool or warm water into the ear elicits eye movements.

-Be able to explain how optokinetic nystagmus aids the VOR.

-Be able to describe the characteristics of the 6 types of eye movements we make (counting fixation as an “eye movement”).

-Be able to characterize the changes in accommodation that always accompany vergence and what purpose combined vergence and accommodation serve.

-Be able to describe the neural pathways underlying each of the 6 types of eye movements.

-Be able to characterize the map of visual and motor space on the surface of the superior colliculus (SC).

-Be able to describe the spatial to temporal transformation in saccade processing. - Be able to explain the reciprocal relationship between the activity in the substantia nigra pars reticulata and the SC. What is the caudate doing during a saccade?

Opsoclonus - young baby

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Caloric Testing

Eye (normal)

Target

1 second

20° eye

rotationEye

(cerebellar lesion)

Smooth pursuit example

TIME

Eye (normal)

Target

1 second

20° eye

rotationEye

(cerebellar lesion)

Smooth pursuit example

TIME

Smooth Pursuit Pathways

Saccade Example

Saccade Pathways

Pre Motor Network for Horizontal Saccades

Pre Motor Network for Vertical Saccades

AbducensNucleus

SNr and Superior Colliculus Activity During a Saccade