English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Visual processing in the ketamine-anesthetized monkey Optokinetic and blood oxygenation level-dependent responses

Leopold, D., Plettenberg, H., & Logothetis, N. (2002). Visual processing in the ketamine-anesthetized monkey Optokinetic and blood oxygenation level-dependent responses. Experimental Brain Research, 143(3), 359-372. doi:10.1007/s00221-001-0998-0.

Item is

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Leopold, DA1, 2, Author              
Plettenberg, HK, Author
Logothetis, NK1, 2, Author              
Affiliations:
1Department Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497798              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, Spemannstrasse 38, 72076 Tübingen, DE, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: We used optokinetic responses and functional magnetic resonance imaging (fMRI) to examine visual processing in monkeys whose conscious state was modulated by low doses (1–2 mg/kg) of the dissociative anesthetic ketamine. We found that, despite the animal’s dissociated state and despite specific influences of ketamine on the oculomotor system, optokinetic nystagmus (OKN) could be reliably elicited with large, moving visual patterns. Responses were horizontally bidirectional for monocular stimulation, indicating that ketamine did not eliminate cortical processing of the motion stimulus. Also, results from fMRI directly demonstrated that the cortical blood oxygenation level-dependent (BOLD) response to visual patterns was preserved at the same ketamine doses used to elicit OKN. Finally, in the ketamine-anesthetized state, perceptually bistable motion stimuli produced patterns of spontaneously alternating OKN that normally would be tightly coupled to perceptual changes. These results, taken together, demonstrate that after ketamine administration cortical circuits continue to processes visual patterns in a dose-dependent manner despite the animal’s behavioral dissociation. While perceptual experience is difficult to evaluate under these conditions, oculomotor patterns revealed that the brain not only registers but also acts upon its sensory input, employing it to drive a sensorimotor loop and even responding to a sensory conflict by engaging in spontaneous perception-related state changes. The ketamine-anesthetized monkey preparation thereby offers a safe and viable paradigm for the behavioral and electrophysiological investigation of issues related to conscious perception and anesthesia, as well as neural mechanisms of basic sensory processing.

Details

show
hide
Language(s):
 Dates: 2002-04
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: -
 Identifiers: DOI: 10.1007/s00221-001-0998-0
BibTex Citekey: 922
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Experimental Brain Research
  Other : Exp. Brain Res.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Heidelberg : Springer-Verlag
Pages: - Volume / Issue: 143 (3) Sequence Number: - Start / End Page: 359 - 372 Identifier: ISSN: 0014-4819
CoNE: https://pure.mpg.de/cone/journals/resource/954925398496