Neuroanatomy Draw It To Know It

23. Eye Movements 417

DRAWING 23-3 Horizontal Saccade Details

Neural

integrator

Medial vestibular nucleus & Gaze holding

nucleus prepositus hypoglossi

(of the perihypoglossal complex)

Excitatory

burst

neurons (EBN)

Nucleus reticularis pontis caudalis

(of the paramedian pontine

reticular formation)

Activate ipsilateral abducens

nucleus & ipsilateral inhibitory

burst neurons, inhibit omnipause

neurons, & innervate neural

integrator

Inhibitory

burst

neurons (IBN)

Nucleus paragigantocellularis

dorsalis (of the medullary reticular

formation)

Inhibit the contralateral

abducens nucleus

Omnipause

neurons

Nucleus raphe interpositus Tonic inhibition of excitatory

& inhibitory burst neurons

Frontal eye fields: frontal eye field,

supplementary eye field, dorsolateral

prefrontal cortex. Superior colliculus,

cerebellum, anterior cingulate cortex,

& basal ganglia.

Supraocular

command

centers

Frontal eye fields & superior

colliculus produce contra-

lateral horizontal saccades

CENTER ANATOMY ACTION DEFICIT

Contralateral

volitional horizontal

gaze palsy

Ipsilateral horizontal

gaze palsy

Ocular flutter

Saccade slowing

Leaky integrator