Question

Briefly describe the neural control of eye movement. How can be this tested?

Answer 1

1. Classes of eye movements are vergence and conjugate ,with the later comprised of two types saccadic and smooth   pursuit
2. Eye movements are produced by 6 extraoccular muscles that are innervated by axons of third and sixth cranial nerves.
3. The discharge rate in neurons of the final common path is proportional to the angular deviation of eye. Saccade size is a function of the duration of the high frequency burst in these neurons
4. the superior colliculus codes saccadic vectors whose amplitude and direction is laid out in an orderly fashion and is in register with the visual receptive fields
5. The retinal input to the SC comes predominantly from W-like cells. The cortical downflow from layer 5 complex cells driven by the parasol system

6.The superior colliculus is under cortical control  

Dorso lateral pontine nucleus is used to computes the direction and speed of eye movements (pursuit) necessary to match the velocity and direction of the moving eyeball.