51
|
Combining Theory, Model, and Experiment to Explain How Intrinsic Theta Rhythms Are Generated in an In Vitro Whole Hippocampus Preparation without Oscillatory Inputs. eNeuro 2017; 4:eN-TNC-0131-17. [PMID: 28791333 PMCID: PMC5547196 DOI: 10.1523/eneuro.0131-17.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 07/11/2017] [Accepted: 07/15/2017] [Indexed: 11/21/2022] Open
Abstract
Scientists have observed local field potential theta rhythms (3-12 Hz) in the hippocampus for decades, but understanding the mechanisms underlying their generation is complicated by their diversity in pharmacological and frequency profiles. In addition, interactions with other brain structures and oscillatory drives to the hippocampus during distinct brain states has made it difficult to identify hippocampus-specific properties directly involved in theta generation. To overcome this, we develop cellular-based network models using a whole hippocampus in vitro preparation that spontaneously generates theta rhythms. Building on theoretical and computational analyses, we find that spike frequency adaptation and postinhibitory rebound constitute a basis for theta generation in large, minimally connected CA1 pyramidal (PYR) cell network models with fast-firing parvalbumin-positive (PV+) inhibitory cells. Sparse firing of PYR cells and large excitatory currents onto PV+ cells are present as in experiments. The particular theta frequency is more controlled by PYR-to-PV+ cell interactions rather than PV+-to-PYR cell interactions. We identify two scenarios by which theta rhythms can emerge, and they can be differentiated by the ratio of excitatory to inhibitory currents to PV+ cells, but not to PYR cells. Only one of the scenarios is consistent with data from the whole hippocampus preparation, which leads to the prediction that the connection probability from PV+ to PYR cells needs to be larger than from PYR to PV+ cells. Our models can serve as a platform on which to build and develop an understanding of in vivo theta generation.
Collapse
|
52
|
Schaich Borg J, Srivastava S, Lin L, Heffner J, Dunson D, Dzirasa K, de Lecea L. Rat intersubjective decisions are encoded by frequency-specific oscillatory contexts. Brain Behav 2017; 7:e00710. [PMID: 28638715 PMCID: PMC5474713 DOI: 10.1002/brb3.710] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
INTRODUCTION It is unknown how the brain coordinates decisions to withstand personal costs in order to prevent other individuals' distress. Here we test whether local field potential (LFP) oscillations between brain regions create "neural contexts" that select specific brain functions and encode the outcomes of these types of intersubjective decisions. METHODS Rats participated in an "Intersubjective Avoidance Test" (IAT) that tested rats' willingness to enter an innately aversive chamber to prevent another rat from getting shocked. c-Fos immunoreactivity was used to screen for brain regions involved in IAT performance. Multi-site local field potential (LFP) recordings were collected simultaneously and bilaterally from five brain regions implicated in the c-Fos studies while rats made decisions in the IAT. Local field potential recordings were analyzed using an elastic net penalized regression framework. RESULTS Rats voluntarily entered an innately aversive chamber to prevent another rat from getting shocked, and c-Fos immunoreactivity in brain regions known to be involved in human empathy-including the anterior cingulate, insula, orbital frontal cortex, and amygdala-correlated with the magnitude of "intersubjective avoidance" each rat displayed. Local field potential recordings revealed that optimal accounts of rats' performance in the task require specific frequencies of LFP oscillations between brain regions in addition to specific frequencies of LFP oscillations within brain regions. Alpha and low gamma coherence between spatially distributed brain regions predicts more intersubjective avoidance, while theta and high gamma coherence between a separate subset of brain regions predicts less intersubjective avoidance. Phase relationship analyses indicated that choice-relevant coherence in the alpha range reflects information passed from the amygdala to cortical structures, while coherence in the theta range reflects information passed in the reverse direction. CONCLUSION These results indicate that the frequency-specific "neural context" surrounding brain regions involved in social cognition encodes outcomes of decisions that affect others, above and beyond signals from any set of brain regions in isolation.
Collapse
Affiliation(s)
- Jana Schaich Borg
- Social Science Research Institute Duke University Durham NC USA.,Duke Institute for Brain Sciences Duke University Durham NC USA.,Department of Psychiatry and Behavioral Sciences Stanford University Stanford CA USA
| | - Sanvesh Srivastava
- Department of Statistics and Actuarial Science University of Iowa Iowa City IA USA
| | - Lizhen Lin
- Department of Applied and Computational Mathematics and Statistics University of Notre Dame Notre Dame IN USA
| | - Joseph Heffner
- Department of Psychology, Cognitive Linguistic and Psychological Sciences Brown University Providence RI USA
| | - David Dunson
- Department of Statistical Science Duke University Durham NC USA
| | - Kafui Dzirasa
- Duke Institute for Brain Sciences Duke University Durham NC USA.,Department of Psychiatry and Behavioral Sciences Duke University Medical Center Durham NC USA.,Department of Neurobiology Duke University Medical Center Durham NC USA.,Department of Neurosurgery Duke University Medical Center Durham NC USA.,Department of Biomedical Engineering Duke University Durham NC USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences Stanford University Stanford CA USA
| |
Collapse
|
53
|
Yoles-Frenkel M, Cohen O, Bansal R, Horesh N, Ben-Shaul Y. In vivo stimulus presentation to the mouse vomeronasal system: Surgery, experiment, setup, and software. J Neurosci Methods 2017; 285:19-32. [PMID: 28476589 DOI: 10.1016/j.jneumeth.2017.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 04/30/2017] [Accepted: 05/01/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Achieving controlled stimulus delivery is a major challenge in the physiological analysis of the vomeronasal system (VNS). NEW METHOD We provide a comprehensive description of a setup allowing controlled stimulus delivery into the vomeronasal organ (VNO) of anesthetized mice. VNO suction is achieved via electrical stimulation of the sympathetic nerve trunk (SNT) using cuff electrodes, followed by flushing of the nasal cavity. Successful application of this methodology depends on several aspects including the surgical preparation, fabrication of cuff electrodes, experimental setup modifications, and the stimulus delivery and flushing. Here, we describe all these aspects in sufficient detail to allow other researchers to readily adopt it. We also present a custom written MATLAB based software with a graphical user interface that controls all aspects of the actual experiment, including trial sequencing, hardware control, and data logging. RESULTS The method allows measurement of stimulus evoked sensory responses in brain regions that receive vomeronasal inputs. An experienced investigator can complete the entire surgical procedure within thirty minutes. COMPARISON WITH EXISTING METHODS This is the only approach that allows repeated and controlled stimulus delivery to the intact VNO, employing the natural mode of stimulus uptake. The approach is economical with respect to stimuli, requiring stimulus volumes as low as 1-2μl. CONCLUSIONS This comprehensive description will allow other investigators to adapt this setup to their own experimental needs and can thus promote our physiological understanding of this fascinating chemosensory system. With minor changes it can also be adapted for other rodent species.
Collapse
Affiliation(s)
- Michal Yoles-Frenkel
- Department of Medical Neurobiology, The Faculty of Medicine, The Hebrew University of Jerusalem, POB 12272, 9112102 Jerusalem, Israel.
| | - Oksana Cohen
- Department of Medical Neurobiology, The Faculty of Medicine, The Hebrew University of Jerusalem, POB 12272, 9112102 Jerusalem, Israel.
| | - Rohini Bansal
- Department of Medical Neurobiology, The Faculty of Medicine, The Hebrew University of Jerusalem, POB 12272, 9112102 Jerusalem, Israel.
| | - Noa Horesh
- Department of Medical Neurobiology, The Faculty of Medicine, The Hebrew University of Jerusalem, POB 12272, 9112102 Jerusalem, Israel.
| | - Yoram Ben-Shaul
- Department of Medical Neurobiology, The Faculty of Medicine, The Hebrew University of Jerusalem, POB 12272, 9112102 Jerusalem, Israel.
| |
Collapse
|
54
|
Sekulić V, Skinner FK. Computational models of O-LM cells are recruited by low or high theta frequency inputs depending on h-channel distributions. eLife 2017; 6. [PMID: 28318488 PMCID: PMC5409828 DOI: 10.7554/elife.22962] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 03/19/2017] [Indexed: 01/06/2023] Open
Abstract
Although biophysical details of inhibitory neurons are becoming known, it is challenging to map these details onto function. Oriens-lacunosum/moleculare (O-LM) cells are inhibitory cells in the hippocampus that gate information flow, firing while phase-locked to theta rhythms. We build on our existing computational model database of O-LM cells to link model with function. We place our models in high-conductance states and modulate inhibitory inputs at a wide range of frequencies. We find preferred spiking recruitment of models at high (4-9 Hz) or low (2-5 Hz) theta depending on, respectively, the presence or absence of h-channels on their dendrites. This also depends on slow delayed-rectifier potassium channels, and preferred theta ranges shift when h-channels are potentiated by cyclic AMP. Our results suggest that O-LM cells can be differentially recruited by frequency-modulated inputs depending on specific channel types and distributions. This work exposes a strategy for understanding how biophysical characteristics contribute to function.
Collapse
Affiliation(s)
- Vladislav Sekulić
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Frances K Skinner
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Departments of Medicine (Neurology) and Physiology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
55
|
Valenza G, Greco A, Gentili C, Lanata A, Toschi N, Barbieri R, Sebastiani L, Menicucci D, Gemignani A, Scilingo EP. Brain-heart linear and nonlinear dynamics during visual emotional elicitation in healthy subjects. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:5497-5500. [PMID: 28269502 DOI: 10.1109/embc.2016.7591971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study investigates brain-heart dynamics during visual emotional elicitation in healthy subjects through linear and nonlinear coupling measures of EEG spectrogram and instantaneous heart rate estimates. To this extent, affective pictures including different combinations of arousal and valence levels, gathered from the International Affective Picture System, were administered to twenty-two healthy subjects. Time-varying maps of cortical activation were obtained through EEG spectral analysis, whereas the associated instantaneous heartbeat dynamics was estimated using inhomogeneous point-process linear models. Brain-Heart linear and nonlinear coupling was estimated through the Maximal Information Coefficient (MIC), considering EEG time-varying spectra and point-process estimates defined in the time and frequency domains. As a proof of concept, we here show preliminary results considering EEG oscillations in the θ band (4-8 Hz). This band, indeed, is known in the literature to be involved in emotional processes. MIC highlighted significant arousal-dependent changes, mediated by the prefrontal cortex interplay especially occurring at intermediate arousing levels. Furthermore, lower and higher arousing elicitations were associated to not significant brain-heart coupling changes in response to pleasant/unpleasant elicitations.
Collapse
|
56
|
Minge D, Senkov O, Kaushik R, Herde MK, Tikhobrazova O, Wulff AB, Mironov A, van Kuppevelt TH, Oosterhof A, Kochlamazashvili G, Dityatev A, Henneberger C. Heparan Sulfates Support Pyramidal Cell Excitability, Synaptic Plasticity, and Context Discrimination. Cereb Cortex 2017; 27:903-918. [PMID: 28119345 PMCID: PMC5390399 DOI: 10.1093/cercor/bhx003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 12/04/2016] [Accepted: 01/04/2017] [Indexed: 02/06/2023] Open
Abstract
Heparan sulfate (HS) proteoglycans represent a major component of the extracellular matrix and are critical for brain development. However, their function in the mature brain remains to be characterized. Here, acute enzymatic digestion of HS side chains was used to uncover how HSs support hippocampal function in vitro and in vivo. We found that long-term potentiation (LTP) of synaptic transmission at CA3-CA1 Schaffer collateral synapses was impaired after removal of highly sulfated HSs with heparinase 1. This reduction was associated with decreased Ca2+ influx during LTP induction, which was the consequence of a reduced excitability of CA1 pyramidal neurons. At the subcellular level, heparinase treatment resulted in reorganization of the distal axon initial segment, as detected by a reduction in ankyrin G expression. In vivo, digestion of HSs impaired context discrimination in a fear conditioning paradigm and oscillatory network activity in the low theta band after fear conditioning. Thus, HSs maintain neuronal excitability and, as a consequence, support synaptic plasticity and learning.
Collapse
Affiliation(s)
- Daniel Minge
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Oleg Senkov
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Rahul Kaushik
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Michel K. Herde
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Olga Tikhobrazova
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
| | - Andreas B. Wulff
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Andrey Mironov
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
- Central Research Laboratory, Nizhny Novgorod State Medical Academy, 603005 Nizhny Novgorod, Russia
| | - Toin H. van Kuppevelt
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Arie Oosterhof
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gaga Kochlamazashvili
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
- Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, 39120 Magdeburg, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
- Institute of Neurology, University College London, London WC1N 3BG, UK
| |
Collapse
|
57
|
Synchronous Infra-Slow Bursting in the Mouse Accessory Olfactory Bulb Emerge from Interplay between Intrinsic Neuronal Dynamics and Network Connectivity. J Neurosci 2017; 37:2656-2672. [PMID: 28148726 DOI: 10.1523/jneurosci.3107-16.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 11/21/2022] Open
Abstract
Rhythmic neuronal activity of multiple frequency bands has been described in many brain areas and attributed to numerous brain functions. Among these, little is known about the mechanism and role of infra-slow oscillations, which have been demonstrated recently in the mouse accessory olfactory bulb (AOB). Along with prolonged responses to stimuli and distinct network connectivity, they inexplicably affect the AOB processing of social relevant stimuli. Here, we show that assemblies of AOB mitral cells are synchronized by lateral interactions through chemical and electrical synapses. Using a network model, we demonstrate that the synchronous oscillations in these assemblies emerge from interplay between intrinsic membrane properties and network connectivity. As a consequence, the AOB network topology, in which each mitral cell receives input from multiple glomeruli, enables integration of chemosensory stimuli over extended time scales by interglomerular synchrony of infra-slow bursting. These results provide a possible functional significance for the distinct AOB physiology and topology. Beyond the AOB, this study presents a general model for synchronous infra-slow bursting in neuronal networks.SIGNIFICANCE STATEMENT Infra-slow rhythmic neuronal activity with a very long (>10 s) duration has been described in many brain areas, but little is known about the role of this activity and the mechanisms that produce it. Here, we combine experimental and computational methods to show that synchronous infra-slow bursting activity in mitral cells of the mouse accessory olfactory bulb (AOB) emerges from interplay between intracellular dynamics and network connectivity. In this novel mechanism, slow intracellular Na+ dynamics endow AOB mitral cells with a weak tendency to burst, which is further enhanced and stabilized by chemical and electrical synapses between them. Combined with the unique topology of the AOB network, infra-slow bursting enables integration and binding of multiple chemosensory stimuli over a prolonged time scale.
Collapse
|
58
|
Hernández-Pérez JJ, Gutiérrez-Guzmán BE, Olvera-Cortés ME. Hippocampal strata theta oscillations change their frequency and coupling during spatial learning. Neuroscience 2016; 337:224-241. [PMID: 27615031 DOI: 10.1016/j.neuroscience.2016.09.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 08/24/2016] [Accepted: 09/01/2016] [Indexed: 11/18/2022]
Abstract
The theta rhythm is necessary for hippocampal-dependent spatial learning. It has been proposed that each hippocampal stratum can generate a current theta dipole. Therefore, considering that each hippocampal circuit (CA1, CA3, and Dentate Gyrus (DG)) contributes differently to distinct aspects of a spatial memory, the theta oscillations on each stratum and their couplings may exhibit oscillatory dynamics associated with different stages of learning. To test this hypothesis, the theta oscillations from five hippocampal strata were recorded in the rat during different stages of learning in a Morris maze. The peak power, the relative power (RP) and the coherence between hippocampal strata were analyzed. The early acquisition stage of the Morris task was characterized by the predominance of slow frequency theta activity and high coupling between specific hippocampal strata at slow frequencies. However, on the last training day, the theta oscillations were faster in all hippocampal strata, with tighter coupling at fast frequencies between the CA3 pyramidal stratum and other strata. Our results suggest that modifications to the theta frequency and its coupling can be a means by which the hippocampus differentially operates during acquisition and retrieval states.
Collapse
Affiliation(s)
- J Jesús Hernández-Pérez
- Laboratorio de Neurofisiología Experimental, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia, Michoacán, Mexico; Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, Mexico.
| | - Blanca E Gutiérrez-Guzmán
- Laboratorio de Neurofisiología Experimental, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia, Michoacán, Mexico; Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro, Mexico
| | - María E Olvera-Cortés
- Laboratorio de Neurofisiología Experimental, División de Neurociencias, Centro de Investigación Biomédica de Michoacán, Instituto Mexicano del Seguro Social, Morelia, Michoacán, Mexico
| |
Collapse
|