title: Spatio-temporal response properties of local field potentials in the primate superior colliculus.
abstract: Local field potentials (LFPs) are becoming increasingly popular in neurophysiological studies. However, to date, most of the knowledge about LFPs has been obtained from cortical recordings. Here, we recorded single unit activity (SUA) and LFPs simultaneously from the superior colliculus (SC) of behaving rhesus monkeys. The SC is a midbrain structure that plays a central role in the visual orienting response. Previous studies have characterised the visual and visuomotor response properties of SUA in the superficial layers of the SC and the intermediate layers of the SC, respectively. We found that the signal properties of SUA were well preserved in the LFPs recorded from the SC. The SUA and LFPs had similar spatial and temporal properties, and the response properties of LFPs differed across layers, i.e. purely visual in the superficial layers of the SC but showing significant motor responses in the intermediate layers of the SC. There were also differences between SUA and LFPs. LFPs showed a significant reversal of activity following the phasic visual response, suggesting that the neighboring neurons were suppressed. The results indicate that the LFP can be used as a reliable measure of the SC activity in lieu of SUA, and open up a new way to assess sensorimotor processing within the SC.
authors.affiliation: Centre for Neuroscience Studies, Botterell Hall, Queen's University, 18 Stuart Street, Kingston, K7L 3N6, ON, Canada.
authors.forename: Takuro
authors.initials: T
authors.lastname: Ikeda
authors.forename: Susan E
authors.initials: SE
authors.lastname: Boehnke
authors.forename: Robert A
authors.initials: RA
authors.lastname: Marino
authors.forename: Brian J
authors.initials: BJ
authors.lastname: White
authors.forename: Chin-An
authors.initials: CA
authors.lastname: Wang
authors.forename: Ron
authors.initials: R
authors.lastname: Levy
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Munoz
mesh_terms: D000818:Animals; D058256:Brain Waves / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D009474:Neurons / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D012438:Saccades; D013477:Superior Colliculi / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
keywords: eye movements; rhesus monkey (Macaca mulatta); saccade; single unit activity; vision