Long-term potentiation and depression phenomena in human induced pluripotent stem cell-derived cortical neurons
-
1
Tohoku Institute of Technology, Department of Electronics, Japan
Motivation
Plasticity such as long-term potentiation (LTP) and long-term potentiation depression (LTD) in neuronal networks has been analyzed using in vitro and in vivo techniques in simple animals to understand learning, memory, and development in brain function. Human induced pluripotent stem cell (hiPSC)-derived neurons may be effectively used for understanding the plasticity mechanism in human neuronal networks, thereby elucidating disease mechanisms and drug discoveries. In this study, we attempted the induction of LTP and LTD phenomena in a cultured hiPSC-derived cerebral cortical neuronal network using multi-electrode array (MEA) systems.
Material and Methods
hiPSC-derived cerebral cortical neurons (hyCCNs; Axol Bioscience Inc., UK) [1] were cultured (density, 1.0 ~ 106 cells/cm2) on MEA chips (MED-P515A; Alpha Med Scientific), and the extracellular signals in spontaneous firings and evoked responses were obtained by the MEA system (MED64-Basic; Alpha Med Scientific). To investigate whether the LTP and LTD phenomena in hiPSC-derived cerebral cortical neurons are generated by electrical stimulation, we administered high-frequency stimulation (HFS) to the MEA chips. We selected two electrodes (labeled as A and B ch) from a total of 64 and applied electrical stimulus to A ch and B ch after 10 ms (termed gpaired stimulationh). Electrical stimulus consisted of a single bipolar pulse (100 ƒÊs at +30 ƒÊA, followed by 100 ƒÊs at 30 ƒÊA). For HFS, 20 trains of paired stimulation at 10 Hz were applied at 120 ~ at 4 s intervals. To evaluate the effect of HFS by evoked responses, we applied a test stimulus alternating between A ch and B ch every 15 s for 60 min before and after HFS, respectively. The test stimulus consisted of a single bipolar pulse (100 ƒÊs at +20 ƒÊA, followed by 100 ƒÊs at 20 ƒÊA).
Results
HFS produced a potentiated and depressed transmission in a neuronal circuit for 1 h in the evoked responses by test stimulus. The cross-correlation of responses revealed that spike patterns with specific timing were generated during LTP induction and disappeared during LTD induction and that the hiPSC-derived cortical neuronal network has the potential to repeatedly express the spike pattern with a precise timing change within 0.5 ms. We also detected the phenomenon for late-phase LTP (L-LTP) like plasticity and the effects for synchronized burst firing (SBF) in spontaneous firings by HFS.[2]
Discussion
@In the present study, we demonstrated that HFS induced the LTP and LTD phenomena in a cultured hiPSC-derived cerebral cortical neuronal network as the change in spike pattern. Plasticity was widespread for 64 electrodes. These results indicate heterosynaptically induced plasticity in the network. We consider that our results of the LTP and LTD phenomena are related to spike timing-dependent plasticity in a dense hiPSC-derived cortical neuronal network. We also showed that the spikes at specific timing were generated during LTP induction and disappeared during LTD induction and that the timing of spikes was accurately changed within 0.5 ms. These results suggest that an increase or decrease of a particular spike pattern occurred in the network rather than the change of random firing pattern and that a hiPSC-derived cortical neuronal network has the potential to repeatedly express the spike pattern with precise timing. Future challenges include the clarification of the respective stimulation protocols for LTP and LTD, dependency in culture days, detailed analysis between neurons, and difference between human and rat neurons.
Conclusion
We detected the LTP and LTD phenomena in a hiPSC-derived neuronal network as the change of spike pattern. The studies of plasticity using hiPSC-derived neurons and a MEA system may be beneficial for clarifying the functions of human neuronal circuits and for applying to drug screening [2].
Reference
[1] Shi Y, Kirwan P, Livesey FJ. Directed differentiation of human pluripotent stem cells to cerebral cortex neurons and neural networks. Nat Protoc. 2012; 7(10):1836-46.
[2] Odawara A, Katoh H, Matsuda N, Suzuki I. Induction of long-term potentiation and depression phenomena in human induced pluripotent stem cell-derived cortical neurons. Biochem Biophys Res Commun. 2016; 469(4):856-62.
Figure Legend
Induction of long-term potentiation (LTP) and long-term depression (LTD) by high-frequency stimulation (HFS). (A) Induction of LTP. (a) The waveforms represent the typical evoked responses before and after HFS, which was applied to 30 and 35 ch. The number of spikes was increased after stimulation. (b) Time course of the number of spikes in evoked responses at 34 ch before and after HFS for 60 min, respectively. Test stimuli were applied to 35 ch every 30 s. Plot of data show average } S.E. for 3 min (n = 6). The average before HFS for 60 min represents 100%. (c) Grids showing the 64 electrodes where colored electrodes changed the number of spikes per one stimulus. Electrodes that detected a higher increase of the number of spikes are shown in red (maximum: 14 spikes). (B) Induction of LTD. (a) The waveforms represent the typical evoked responses before and after HFS.The number of spikes was decreased after stimulation. (b) Time course of the number of spikes in evoked responses at 45 ch before and after HFS for 60 min, respectively. (c) Grids showing the 64 electrodes where colored electrodes changed the number of spikes per one stimulus. Electrodes that detected a lower decrease of the number of spikes are shown in blue (minimum: 10 spikes). Created based upon data from [2].
Acknowledgements
We thank Axol Bioscience and Alpha Med Scientific Company for supporting this research. This study was supported by the JSPS KAKENHI Grant Number 26560247, 14J11194.
Keywords:
LTP,
plasticity,
LTD,
Human iPSC-derived cerebral cortical
Conference:
MEA Meeting 2016 |
10th International Meeting on Substrate-Integrated Electrode Arrays, Reutlingen, Germany, 28 Jun - 1 Jul, 2016.
Presentation Type:
Poster Presentation
Topic:
MEA Meeting 2016
Citation:
Odawara
A,
Katoh
H,
Matsuda
N and
Suzuki
I
(2016). Long-term potentiation and depression phenomena in human induced pluripotent stem cell-derived cortical neurons.
Front. Neurosci.
Conference Abstract:
MEA Meeting 2016 |
10th International Meeting on Substrate-Integrated Electrode Arrays.
doi: 10.3389/conf.fnins.2016.93.00065
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:
22 Jun 2016;
Published Online:
24 Jun 2016.
*
Correspondence:
Dr. Ikuro Suzuki, Tohoku Institute of Technology, Department of Electronics, Sendai, Japan, i-suzuki@tohtech.ac.jp