English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  The hemodynamic initial-dip consists of both volumetric and oxymetric changes correlated to localized spiking activity

Zaidi, A., Birbaumer, N., Fetz, E., Logothetis, N., & Sitaram, R. (submitted). The hemodynamic initial-dip consists of both volumetric and oxymetric changes correlated to localized spiking activity.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0001-7D1E-3 Version Permalink: http://hdl.handle.net/21.11116/0000-0001-80D2-0
Genre: Journal Article

Files

show Files

Locators

show
hide
Locator:
Link (Any fulltext)
Description:
-

Creators

show
hide
 Creators:
Zaidi, AD1, 2, Author              
Birbaumer, N, Author
Fetz, E, Author
Logothetis, NK1, 2, Author              
Sitaram, R1, 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, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: The initial-dip is a transient decrease frequently observed in functional neuroimaging signals, immediately after stimulus onset, and is believed to originate from a rise in deoxy-hemoglobin (HbR) caused by local neural activity. It has been shown to be more spatially specific than the hemodynamic response, and is believed to represent focal neuronal activity. However, despite being observed in various neuroimaging modalities (such as fMRI, fNIRS, etc), its origins are disputed and its neuronal correlates unknown. Here, we show that the initial-dip is dominated by a decrease in total-hemoglobin (HbT). We also find a biphasic response in HbR, with an early decrease and later rebound. However, HbT decreases were always large enough to counter spiking-induced increases in HbR. Moreover, the HbT-dip and HbR-rebound were strongly coupled to highly localized spiking activity. Our results suggest that the HbT-dip helps prevent accumulation of spiking-induced HbR concentration in capillaries by flushing out HbT, probably by active venule dilation.

Details

show
hide
Language(s):
 Dates: 2018-02
 Publication Status: Submitted
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: DOI: 10.1101/259895
BibTex Citekey: ZaidiBFLS2018
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: -
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: - Sequence Number: - Start / End Page: - Identifier: -