1
|
Kamm GB, Boffi JC, Zuza K, Nencini S, Campos J, Schrenk-Siemens K, Sonntag I, Kabaoğlu B, El Hay MYA, Schwarz Y, Tappe-Theodor A, Bruns D, Acuna C, Kuner T, Siemens J. A synaptic temperature sensor for body cooling. Neuron 2021; 109:3283-3297.e11. [PMID: 34672983 DOI: 10.1016/j.neuron.2021.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/01/2021] [Accepted: 09/30/2021] [Indexed: 10/20/2022]
Abstract
Deep brain temperature detection by hypothalamic warm-sensitive neurons (WSNs) has been proposed to provide feedback information relevant for thermoregulation. WSNs increase their action potential firing rates upon warming, a property that has been presumed to rely on the composition of thermosensitive ion channels within WSNs. Here, we describe a synaptic mechanism that regulates temperature sensitivity of preoptic WSNs and body temperature. Experimentally induced warming of the mouse hypothalamic preoptic area in vivo triggers body cooling. TRPM2 ion channels facilitate this homeostatic response and, at the cellular level, enhance temperature responses of WSNs, thereby linking WSN function with thermoregulation for the first time. Rather than acting within WSNs, we-unexpectedly-find TRPM2 to temperature-dependently increase synaptic drive onto WSNs by disinhibition. Our data emphasize a network-based interoceptive paradigm that likely plays a key role in encoding body temperature and that may facilitate integration of diverse inputs into thermoregulatory pathways.
Collapse
Affiliation(s)
- Gretel B Kamm
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Juan C Boffi
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Kristina Zuza
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Sara Nencini
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Joaquin Campos
- Chica and Heinz Schaller Foundation, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Katrin Schrenk-Siemens
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Ivo Sonntag
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Burçe Kabaoğlu
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Muad Y Abd El Hay
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Yvonne Schwarz
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Anke Tappe-Theodor
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Dieter Bruns
- Institute for Physiology, Center of Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Claudio Acuna
- Chica and Heinz Schaller Foundation, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Thomas Kuner
- Department of Functional Neuroanatomy, Institute for Anatomy and Cell Biology, University of Heidelberg, Im Neuenheimer Feld 307, 69120 Heidelberg, Germany
| | - Jan Siemens
- Department of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany; Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Meyerhofstraße 1, 69117 Heidelberg, Germany.
| |
Collapse
|
2
|
Sharma B, Sengupta T, Chandra Vishwakarma L, Akhtar N, Mallick HN. Muscle temperature is least altered during total sleep deprivation in rats. J Therm Biol 2021; 98:102910. [PMID: 34016337 DOI: 10.1016/j.jtherbio.2021.102910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/11/2021] [Accepted: 03/11/2021] [Indexed: 11/27/2022]
Abstract
It has often been said that the brain is mostly benefitted from sleep. To understand the importance of sleep, extensive studies on other organs are too required. One such unexplored area is the understanding of muscle physiology during the sleep-wake cycle. Changes in muscle tone with different sleep phases are evident from the rapid eye movement sleep muscle atonia. There is variation in brain and body temperature during sleep stages, the brain temperature being higher during rapid eye movement sleep than slow-wave sleep. However, the change in muscle temperature with different sleep stages is not known. In this study, we have implanted pre-calibrated K-type thermocouples in the hypothalamus and the dorsal nuchal muscle, and a peritoneal transmitter to monitor the hypothalamic, muscle, and body temperature respectively in rats during 24 h sleep-wake cycle. The changes in muscle, body, and hypothalamic temperature during total sleep deprivation were also monitored. During normal sleep-wake stages, the temperature in the decreasing order was that of the hypothalamus, body, and muscle. Total sleep deprivation by gentle handling caused a significant increase in hypothalamic and body temperature, while there was least change in the muscle temperature. The circadian rhythm of the hypothalamic and body temperature in the sleep-deprived rats was disrupted, while the same was preserved in the muscle temperature. The results of our study show that muscle atonia during rapid eye movement sleep is a physiologically regulated thermally quiescent muscle state offering a conducive environment for muscle rest and repair.
Collapse
Affiliation(s)
- Binney Sharma
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Trina Sengupta
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, 110029, India; Department of Physiology, All India Institute of Medical Sciences, Jodhpur, 342005, India.
| | - Lal Chandra Vishwakarma
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Nasreen Akhtar
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Hruda Nanda Mallick
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, 110029, India; Department of Physiology, Faculty of Medicine & Health Sciences, SGT University, Gurgaon, Haryana, 122505, India.
| |
Collapse
|