Wikia

Psychology Wiki

Paramedian pontine reticular formation

Talk0
34,135pages on
this wiki

Redirected from PPRF

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


The paramedian pontine reticular formation, or PPRF, is a brain region, without clearly defined borders, in the center of the pons. It is involved in the coordination of eye movements, particularly saccades.

Inputs, outputs, functionsEdit

The PPRF is located anterior and lateral to the medial longitudinal fasciculus (MLF). It receives input from the superior colliculus via the predorsal bundle and from the frontal eye fields via frontopontine fibers. The rostral PPRF probably coordinates horizontal saccades; the caudal PPRF may be the generator of both horizontal and vertical saccades. In particular, activity of the excitatory burst neurons (EBNs) in the PPRF generates the "pulse" movement that initiates a saccade. In the case of horizontal saccades the "pulse" information is conveyed via axonal fibers to the abducens nucleus, initiating lateral eye movements. The angular velocity of the eye during horizontal saccade ranges from 100 to 700 degrees per second. Larger saccades have faster pulses; the PPRF is involved in this determination.[1]

LesionsEdit

Unilateral lesions of the PPRF produce characteristic findings:[2]

  • Loss of horizontal saccades directed towards the side of the lesion, no matter the current position of gaze
  • Contralateral gaze deviation (acute lesions, such as early stroke, only)
  • Gaze-evoked lateral nystagmus on looking away from the side of the lesion
  • Bilateral lesions produce horizontal gaze palsy and slowing of vertical saccades

See alsoEdit

ReferencesEdit

  1. ^  Brazis, P.W., Masdeu, J.C., and Biller, J. Localization in Clinical Neurology, 4th edition. Lippincott, Williams, and Wilkins, Philadelphia, 2001; pp. 213-216. ISBN 0-7817-2843-6
  2. ^  Adapted from Leigh, R.J., and Zee, D.S. The Neurology of Eye Movements, 3rd edition. Oxford University Press, Oxford, England, 1999; p. 499. ISBN 0-19-512-972-5

External linksEdit


This page uses Creative Commons Licensed content from Wikipedia (view authors).

Around Wikia's network

Random Wiki