Comparison of Saccade-Associated Neuronal Activity in the Primate Central Mesencephalic and Paramedian Pontine Reticular Formations
- 1 August 2007
- journal article
- research article
- Published by American Physiological Society in Journal of Neurophysiology
- Vol. 98 (2), 835-850
- https://doi.org/10.1152/jn.00308.2007
Abstract
The oculomotor system must convert signals representing the target of an intended eye movement into appropriate input to drive the individual extraocular muscles. Neural models propose that this transformation may involve either a decomposition of the intended eye displacement signal into horizontal and vertical components or an implicit process whereby component signals do not predominate until the level of the motor neurons. Thus decomposition models predict that premotor neurons should primarily encode component signals while implicit models predict encoding of off-cardinal optimal directions by premotor neurons. The central mesencephalic reticular formation (cMRF) and paramedian pontine reticular formation (PPRF) are two brain stem regions that likely participate in the development of motor activity since both structures are anatomically connected to nuclei that encode movement goal (superior colliculus) and generate horizontal eye movements (abducens nucleus). We compared cMRF and PPRF neurons and found they had similar relationships to saccade dynamics, latencies, and movement fields. Typically, the direction preference of these premotor neurons was horizontal, suggesting they were related to saccade components. To confirm this supposition, we studied the neurons during a series of oblique saccades that caused “component stretching” and thus allowed the vectorial (overall) saccade velocity to be dissociated from horizontal component velocity. The majority of cMRF and PPRF neurons encoded component velocity across all saccades, supporting decomposition models that suggest horizontal and vertical signals are generated before the level of the motoneurons. However, we also found novel vectorial eye velocity encoding neurons that may have important implications for saccade control.Keywords
This publication has 58 references indexed in Scilit:
- Horizontal eye movement networks in primates as revealed by retrograde transneuronal transfer of rabies virus: Differences in monosynaptic input to “slow” and “fast” abducens motoneuronsJournal of Comparative Neurology, 2006
- Dynamic Ensemble Coding of Saccades in the Monkey Superior ColliculusJournal of Neurophysiology, 2006
- Saccade-Related, Long-Lead Burst Neurons in the Monkey Rostral PonsJournal of Neurophysiology, 2006
- Discharge Dynamics of Oculomotor Neural Integrator Neurons During Conjugate and Disjunctive Saccades and FixationJournal of Neurophysiology, 2003
- Density gradients of trans‐synaptically labeled collicular neurons after injections of rabies virus in the lateral rectus muscle of the rhesus monkeyJournal of Comparative Neurology, 2002
- The microscopic anatomy and physiology of the mammalian saccadic systemProgress in Neurobiology, 1996
- Anatomy and physiology of saccadic burst neurons in the alert squirrel monkey. I. Excitatory burst neuronsJournal of Comparative Neurology, 1986
- Midbrain paresis of horizontal gazeAnnals of Neurology, 1984
- A quantitative method of computer analysis of spike train data collected from behaving animalsBrain Research, 1979