Transient loss of interhemispheric functional connectivity following unilateral cortical spreading depression in awake rats

Cephalalgia ◽  
2020 ◽  
pp. 033310242097017
Author(s):  
Lyudmila V Vinogradova ◽  
Elena M Suleymanova ◽  
Tatiana M Medvedeva

Objective Growing evidence shows a critical role of network disturbances in the pathogenesis of migraine. Unilateral pattern of neurological symptoms of aura suggests disruption of interhemispheric interactions during the early phase of a migraine attack. Using local field potentials data from the visual and motor cortices, this study explored effects of unilateral cortical spreading depression, the likely pathophysiological mechanism of migraine aura, on interhemispheric functional connectivity in freely behaving rats. Methods Temporal evolution of the functional connectivity was evaluated using mutual information and phase synchronization measures applied to local field potentials recordings obtained in homotopic points of the motor and visual cortices of the two hemispheres in freely behaving rats after induction of a single unilateral cortical spreading depression in the somatosensory S1 cortex and sham cortical stimulation. Results Cortical spreading depression was followed by a dramatic broadband loss of interhemispheric functional connectivity in the visual and motor regions of the cortex. The hemispheric disconnection started after the end of the depolarization phase of cortical spreading depression, progressed gradually, and terminated by 5 min after initiation of cortical spreading depression. The network impairment had region- and frequency-specific characteristics and was more pronounced in the visual cortex than in the motor cortex. The period of impaired neural synchrony coincided with post-cortical spreading depression electrographic aberrant activation of the ipsilateral cortex and abnormal behavior. Conclusion The study provides the first evidence that unilateral cortical spreading depression induces a reversible loss of functional hemispheric connectivity in the cortex of awake animals. Given a critical role of long-distance cortical synchronization in sensory processing and sensorimotor integration, the post-cortical spreading depression breakdown of functional connectivity may contribute to neuropathological mechanisms of aura generation.


Neuron ◽  
2013 ◽  
Vol 79 (2) ◽  
pp. 375-390 ◽  
Author(s):  
Michael W. Reimann ◽  
Costas A. Anastassiou ◽  
Rodrigo Perin ◽  
Sean L. Hill ◽  
Henry Markram ◽  
...  


2015 ◽  
Vol 96 (3) ◽  
pp. 134-140 ◽  
Author(s):  
Timo Ruusuvirta ◽  
Arto Lipponen ◽  
Eeva-Kaarina Pellinen ◽  
Markku Penttonen ◽  
Piia Astikainen


2012 ◽  
Vol 109 (46) ◽  
pp. 18985-18990 ◽  
Author(s):  
A. Tozzi ◽  
A. de Iure ◽  
M. Di Filippo ◽  
C. Costa ◽  
S. Caproni ◽  
...  


2020 ◽  
Vol 91 (8) ◽  
pp. e10.3-e11
Author(s):  
Luis Manssuer ◽  
Valerie Voon ◽  
Chen Cheng Zhang ◽  
Linbin Wang

Objectives/AimsTo examine the causal role of the subthalamic nucleus (STN) in externally cued or internally generated decisions to execute or withhold an action by recording and stimulating neural activity in this region using deep brain stimulation (DBS) electrodes implanted for the treatment of Parkinson’s disease (PD).Methods20 PD patients completed an intentional inhibition task in which they were instructed by visual cues to go, stop or choose to go or stop. Each cue was on the screen until the patient pressed a button with their left thumb or for a maximum of 1500 ms and was preceded by a fixation cross for 1000–1500 ms. Local field potentials (LFP) were simultaneously recorded from the left STN and stimulated in the right STN at the clinical frequency of 130Hz or theta frequency 7Hz for 500 ms prior to the onset of the cue on half of the choice trials.ResultsOn non-stimulation choice trials, analysis of the LFP’s showed a significant decrease in theta activity when patients chose to stop compared to go. This difference began prior to the onset of the response. Behaviourally, patients chose to respond less when the STN was stimulated at a frequency of 7 hz for 500 ms prior to the onset of the cue but not at 130 Hz.On non-stimulation choice trials, analysis of the LFP’s also showed that there was a significant decrease in theta activity when patients chose to stop compared to go. This difference began prior to the onset of the response.ConclusionsThe findings suggest that pre-existing theta activity in the STN may bias one’s pre-disposition to choose to initiate an action and that stimulation of this activity may interfere with this process.



eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Carmen Varela ◽  
Matthew A Wilson

Sleep oscillations in the neocortex and hippocampus are critical for the integration of new memories into stable generalized representations in neocortex. However, the role of the thalamus in this process is poorly understood. To determine the thalamic contribution to non-REM oscillations (sharp-wave ripples, SWRs; slow/delta; spindles), we recorded units and local field potentials (LFPs) simultaneously in the limbic thalamus, mPFC, and CA1 in rats. We report that the cycles of neocortical spindles provide a key temporal window that coordinates CA1 SWRs with sparse but consistent activation of thalamic units. Thalamic units were phase-locked to delta and spindles in mPFC, and fired at consistent lags with other thalamic units within spindles, while CA1 units that were active during spatial exploration were engaged in SWR-coupled spindles after behavior. The sparse thalamic firing could promote an incremental integration of recently acquired memory traces into neocortical schemas through the interleaved activation of thalamocortical cells.



2019 ◽  
Author(s):  
C Varela ◽  
MA Wilson

AbstractSleep oscillations in neocortex and hippocampus are critical for the integration of new episodic memories into stable generalized representations in neocortex. However, the role of the thalamus in this process is poorly understood.To determine the thalamic contribution to non-REM oscillations (sharp-wave ripples, SWRs; slow/delta; spindles), we recorded units and local field potentials (LFPs) simultaneously in the limbic thalamus, mPFC, and CA1 in rats. We report that the cycles of neocortical spindles provide a key temporal window that coordinates CA1 SWRs with sparse but consistent activation of thalamic units. Thalamic units were phase-locked to delta and spindles in mPFC, and fired at consistent lags with other thalamic units within spindles, while CA1 units that were active during spatial exploration were engaged in SWR-coupled spindles after behavior. The sparse thalamic firing could promote an incremental integration of recently acquired memory traces into neocortical schemas through the interleaved activation of thalamocortical cells.



2011 ◽  
Vol 106 (4) ◽  
pp. 1601-1603 ◽  
Author(s):  
Matthias Witte

How the brain orchestrates the musculoskeletal system to produce complex three-dimensional movements is still poorly understood. Despite first promising results in brain-machine interfaces that translate cortical activity to control output, there is an ongoing debate about which brain signals provide richest information related to movement planning and execution. Novel results by Bansal and colleagues (2011) now suggest that neuronal spiking and local field potentials jointly encode kinematics during skilled reach and grasp movements.



2016 ◽  
Vol 13 (2) ◽  
pp. 026031 ◽  
Author(s):  
Beth A Lopour ◽  
Richard J Staba ◽  
John M Stern ◽  
Itzhak Fried ◽  
Dario L Ringach


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