English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Integration of thalamocortical and callosal inputs by optogenetic activation of the rat corpus callosum (CC) with MRI-guided robotic arm (MgRA)

Chen, Y., Sobczak, F., Pais, P., Schwarz, C., Koretsky, A., & Yu, X. (2019). Integration of thalamocortical and callosal inputs by optogenetic activation of the rat corpus callosum (CC) with MRI-guided robotic arm (MgRA). In 4th Summer Conference of the European Society for Molecular Imaging: Hot Topics in Imaging Technology (TOPIM TECH 2019): Resolution Revolution.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0004-7906-E Version Permalink: http://hdl.handle.net/21.11116/0000-0004-B533-6
Genre: Meeting Abstract

Files

show Files

Creators

show
hide
 Creators:
Chen, Y1, 2, Author              
Sobczak, F1, 2, Author              
Pais, P1, 2, Author              
Schwarz, C, Author
Koretsky, AP, Author
Yu, X1, 2, Author              
Affiliations:
1Research Group Translational Neuroimaging and Neural Control, Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_2528695              
2Max Planck Institute for Biological Cybernetics, Max Planck Society, ou_1497794              

Content

show
hide
Free keywords: -
 Abstract: Introduction The hypothesis that CC inhibits contralateral cortex can explain dampened neural responses in cortex in human and rodents(1-4), e.g., the first stimulus suppressed neural responses to the subsequent stimulus on the other eye within a certain time. Here, we optogenetically activated CC(8) and provided direct evidence for CC-mediated interhemispheric inhibition(II), showing that the direct callosal inputs suppressed evoked calcium and BOLD signals in barrel cortex(BC) by whisker stimulation. Our work links callosal circuit-specific regulation to the global brain dynamic changes based on II(5-7). Methods AAV.CaMKII.ChR2.mCherry was injected into the BC of rats, expressed in callosal projection neurons (CPN) and along their axonal fiber bundles projecting to the opposite BC (Fig.1a), where the GCaMP6f was expressed (Fig.1f). Optogenetic stimulation will be delivered on corpus callosum, followed by a whisker stimulus to the whisker pad with different intervals (0-200 ms) and the paired conditions of each trail were randomized (Fig. 2c). Whole brain BOLD signals were acquired with simultaneous calcium signal in the BC while an MRI-guided robotic arm was used to precisely target the callosal fiber bundle to deliver blue light pulses (473nm) at 2Hz, 10ms width for the fMRI block design (8s on/52s off,13 epochs,Fig.2b,c). Whole brain 3D EPI: TR,1.5s, 400×400×400 μm3 spatial resolution. Results/Discussion Upon the optogenetic stim on CC, salient BOLD signal was detected due to the antidromic activity from the axonal fibers backward to the soma of callosal projection neurons in the ipsilateral BC (Fig.1c,d), further confirmed by LFP (Fig.1e). For the orthodromic activity, there was clear spike for each stimulus at 2Hz, while with higher frequencies, light flashes 2-16 induced responses were consistently weaker than the first response (Fig.1g), Moreover, there was a baseline drift during the whole 40Hz stimulation period (Fig.1g), therefore, confirming the CC-mediated interhemispheric inhibition. With two stimuli paradigm, the anti-dromic activity in the right cortex kept similar for 6 conditions, while the BOLD and calcium signals in the left cortex induced by paired whisker stimuli was the strongest for OW condition, kept suppressed for the O50W and O100W conditions (Fig.2d-h), almost recovered for the O200W condition. Conclusion By taking advantage of fMRI, the optogenetic stimuli on CC and cell-specific calcium signal recordings for layer 5 pyramidal excitatory neurons in the BC, we confirmed the CC-mediated interhemispheric inhibition, further provided direct evidence for the dampened neural responses to subsequent contralateral stimulus after an ipsilateral stimulus for a period of several hundred milliseconds in human and rodents at function level. Acknowledgement We thank Mr. Shanyi Yu for building up the first prototype of the robotic arm, Fine Mechanic and Electronic Workshop at MPI for Biological Cybernetics for MgRA system automation. The financial support of the Max-Planck-Society and the China Scholarship Council (Ph.D. fellowship to Y. Chen) are gratefully acknowledged.

Details

show
hide
Language(s):
 Dates: 2019-07
 Publication Status: Published online
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Method: -
 Identifiers: -
 Degree: -

Event

show
hide
Title: 4th Summer Conference of the European Society for Molecular Imaging: Hot Topics in Imaging Technology (TOPIM TECH 2019): Resolution Revolution
Place of Event: Chania, Greece
Start-/End Date: 2019-07-01 - 2019-07-06

Legal Case

show

Project information

show

Source 1

show
hide
Title: 4th Summer Conference of the European Society for Molecular Imaging: Hot Topics in Imaging Technology (TOPIM TECH 2019): Resolution Revolution
Source Genre: Proceedings
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: - Sequence Number: T-05 Start / End Page: - Identifier: -