1
|
Jeschke M, Ohl FW, Wang X. Effects of Cortical Cooling on Sound Processing in Auditory Cortex and Thalamus of Awake Marmosets. Front Neural Circuits 2022; 15:786740. [PMID: 35069125 PMCID: PMC8766342 DOI: 10.3389/fncir.2021.786740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 12/15/2022] Open
Abstract
The auditory thalamus is the central nexus of bottom-up connections from the inferior colliculus and top-down connections from auditory cortical areas. While considerable efforts have been made to investigate feedforward processing of sounds in the auditory thalamus (medial geniculate body, MGB) of non-human primates, little is known about the role of corticofugal feedback in the MGB of awake non-human primates. Therefore, we developed a small, repositionable cooling probe to manipulate corticofugal feedback and studied neural responses in both auditory cortex and thalamus to sounds under conditions of normal and reduced cortical temperature. Cooling-induced increases in the width of extracellularly recorded spikes in auditory cortex were observed over the distance of several hundred micrometers away from the cooling probe. Cortical neurons displayed reduction in both spontaneous and stimulus driven firing rates with decreased cortical temperatures. In thalamus, cortical cooling led to increased spontaneous firing and either increased or decreased stimulus driven activity. Furthermore, response tuning to modulation frequencies of temporally modulated sounds and spatial tuning to sound source location could be altered (increased or decreased) by cortical cooling. Specifically, best modulation frequencies of individual MGB neurons could shift either toward higher or lower frequencies based on the vector strength or the firing rate. The tuning of MGB neurons for spatial location could both sharpen or widen. Elevation preference could shift toward higher or lower elevations and azimuth tuning could move toward ipsilateral or contralateral locations. Such bidirectional changes were observed in many parameters which suggests that the auditory thalamus acts as a filter that could be adjusted according to behaviorally driven signals from auditory cortex. Future work will have to delineate the circuit elements responsible for the observed effects.
Collapse
Affiliation(s)
- Marcus Jeschke
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany,Auditory Neuroscience and Optogenetics Group, Cognitive Hearing in Primates Laboratory, German Primate Center-Leibniz Institute for Primate Research, Göttingen, Germany,*Correspondence: Marcus Jeschke
| | - Frank W. Ohl
- Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany,Institute of Biology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Xiaoqin Wang
- Laboratory of Auditory Neurophysiology, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Xiaoqin Wang
| |
Collapse
|
2
|
Csernyus B, Szabó Á, Fiáth R, Zátonyi A, Lázár C, Pongrácz A, Fekete Z. A multimodal, implantable sensor array and measurement system to investigate the suppression of focal epileptic seizure using hypothermia. J Neural Eng 2021; 18. [PMID: 34280911 DOI: 10.1088/1741-2552/ac15e6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022]
Abstract
Objective.Local cooling of the brain as a therapeutic intervention is a promising alternative for patients with epilepsy who do not respond to medication.In vitroandin vivostudies have demonstrated the seizure-suppressing effect of local cooling in various animal models. In our work, focal brain cooling in a bicuculline induced epilepsy model in rats is demonstrated and evaluated using a multimodal micro-electrocorticography (microECoG) device.Approach.We designed and experimentally tested a novel polyimide-based sensor array capable of recording microECoG and temperature signals concurrently from the cortical surface of rats. The effect of cortical cooling after seizure onset was evaluated using 32 electrophysiological sites and eight temperature sensing elements covering the brain hemisphere, where injection of the epileptic drug was performed. The focal cooling of the cortex right above the injection site was accomplished using a miniaturized Peltier chip combined with a heat pipe to transfer heat. Control of cooling and collection of sensor data was provided by a custom designed Arduino based electronic board. We tested the experimental setup using an agar gel modelin vitro, and thenin vivoin Wistar rats.Main results.Spatial variation of temperature during the Peltier controlled cooling was evaluated through calibrated, on-chip platinum temperature sensors. We found that frequency of epileptic discharges was not substantially reduced by cooling the cortical surface to 30 °C, but was suppressed efficiently at temperature values around 20 °C. The multimodal array revealed that seizure-like ictal events far from the focus and not exposed to high drop in temperature can be also inhibited at an extent like the directly cooled area.Significance.Our results imply that not only the absolute drop in temperature determines the efficacy of seizure suppression, and distant cortical areas not directly cooled can be influenced.
Collapse
Affiliation(s)
- B Csernyus
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Á Szabó
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary.,Roska Tamás Interdisciplinary Doctoral School, Pázmány Péter Catholic University, Budapest, Hungary
| | - R Fiáth
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
| | - A Zátonyi
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - C Lázár
- Microsystems Laboratory, Institute of Technical Physics and Material Sciences, Center for Energy Research, Budapest, Hungary
| | - A Pongrácz
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| | - Z Fekete
- Research Group for Implantable Microsystems, Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Budapest, Hungary
| |
Collapse
|