Event Abstract

Back to Event

Low-frequency phase-locking of selective human medial temporal lobe neurons to the local field potential of contralateral lateral prefrontal cortex during visual stimulation

Tom Sikkens1, Jessy Possel2, Matthew Self2, Hans Baeyen3, Steven Claus4, Pieter R. Roelfsema2, Cyriel Pennartz1 and Conrado A. Bosman1*
  • 1 University of Amsterdam, Swammerdam Institute for Life Sciences, Center for Neuroscience, Netherlands
  • 2 Netherlands Institute for Neuroscience, Netherlands
  • 3 VU University Medical Center, Department of Neurosurgery, Netherlands
  • 4 Dutch Epilepsy Clinics Foundation, Department of Clinical Neurophysiology, Netherlands

Human medial temporal lobe (MTL) neurons show selective and invariant responses to complex visual stimulation [1], but it is yet unknown whether this activity is supported by a coordinated response of a distributed brain network [2]. To inquire this, we recorded single-neuron and local field potential (LFP) activity during two sessions in eight epilepsy patients implanted with electrodes for presurgical focus localization, in the MTL and lateral prefrontal cortex (LPFC) in both hemispheres (Fig 1A). Patients passively observed pictures of celebrities and relatives for 1 s (stimulation) with interleaved pauses of 0.5 s (baseline) between pictures. Every picture was presented 8 times during a session. Here, we presented preliminary data for 1 patient. We observed 3 MTL neurons (medial left hippocampus [HPC]) with selective responses to stimulation (Fig 1B). The LFP in HPC and LPFC areas revealed an increase of power in a low-frequency band during the stimulation condition, together with a decrease of the beta-band range (Fig 1C). We therefore analyzed interareal connectivity between these regions using the weighted phase-lag index (wPLI), a metric with reduced sensitivity to sample bias and volume conduction effects [3]. We observed a significant increase of wPLI during stimulation in the delta-theta range between HPC and LPFC (Fig 1D). Interestingly, the left HPC connected preferentially to the contralateral LPFC. Finally, we asked whether the observed selective-to-stimulation MTL spikes were phase-locked with the LFP in these areas. We calculated the difference in the pairwise phase consistency (PPC) metric [4] between selective and non-selective spikes and the LFP of the recorded areas. A low-frequency PPC increase in the right LPFC, 0.05 s previous to the MTL spike, was followed by an increase in HPC low-frequency PPC after the spike occurrence, and a decrease in phase-locking with the ipsilateral LPFC (Fig 1E). These results suggest the activation of a low-frequency band network probably initiated at the contralateral LPFC, which may support selective activity of MTL neurons during stimulation.

Figure 1
Image

References

1. Quiroga, R. Q., Reddy, L., Kreiman, G., Koch, C. & Fried, I. Invariant visual representation by single neurons in the human brain. Nature 435, 1102–1107 (2005).
2. Quiroga, R. Q. Concept cells: the building blocks of declarative memory functions. Nat Rev Neurosci 13, 587–597 (2012).
3. Vinck, M., Oostenveld, R., van Wingerden, M., Battaglia, F. & Pennartz, C. M. A. An improved index of phase-synchronization for electrophysiological data in the presence of volume-conduction, noise and sample-size bias. Neuroimage 55, 1548–1565 (2011).
4. Vinck, M., Battaglia, F. P., Womelsdorf, T. & Pennartz, C. M. A. Improved measures of phase-coupling between spikes and the Local Field Potential. J Comput Neurosci 33, 53–75 (2012).

Keywords: intracranial recordings, medial temporal lobe, lateral prefrontal cortex (LPFC), theta oscillations, phase locked neurons

Conference: Neuroinformatics 2014, Leiden, Netherlands, 25 Aug - 27 Aug, 2014.

Presentation Type: Poster, not to be considered for oral presentation

Topic: Electrophysiology

Citation: Sikkens T, Possel J, Self M, Baeyen H, Claus S, Roelfsema PR, Pennartz C and Bosman CA (2014). Low-frequency phase-locking of selective human medial temporal lobe neurons to the local field potential of contralateral lateral prefrontal cortex during visual stimulation. Front. Neuroinform. Conference Abstract: Neuroinformatics 2014. doi: 10.3389/conf.fninf.2014.18.00046

Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.

The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.

Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.

For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.

Received: 26 Apr 2014; Published Online: 04 Jun 2014.

* Correspondence: Dr. Conrado A Bosman, University of Amsterdam, Swammerdam Institute for Life Sciences, Center for Neuroscience, Amsterdam, 1098 XJ, Netherlands, C.A.BosmanVittini@uva.nl