Acute and Reversible Hypothalamic Symptoms in a Lateral Head Impact Mouse Model of Mild Traumatic Brain Injury.

Autor:	O'Reilly-Fong J; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Simpson NJ; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Thirouin ZS; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Bastone PA; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Zaelzer C; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Murtaz A; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada., Bourque CW; Brain Repair and Integrative Neuroscience Program, Research Institute of the McGill University Health Center, Montreal, Canada.
Jazyk:	angličtina
Zdroj:	Neurotrauma reports [Neurotrauma Rep] 2024 Aug 08; Vol. 5 (1), pp. 749-759. Date of Electronic Publication: 2024 Aug 08 (Print Publication: 2024).
DOI:	10.1089/neur.2024.0071
Abstrakt:	Central autonomic and endocrine dysfunctions following traumatic brain injury (TBI) are believed to involve the hypothalamus; however, underlying mechanisms are unknown. Although chronic deficits might be caused by irreversible tissue damage, various neuroendocrine and autonomic symptoms are only observed transiently, suggesting they might result from a temporary alteration in the activity of hypothalamic neurons. We therefore examined if a mouse model of mild TBI could induce reversible autonomic phenotypes and cause acute changes in c-Fos expression within corresponding regions of the hypothalamus. Adult C57Bl/6 male mice were lightly anesthetized with isoflurane and subjected to TBI by lateral head impact using a Gothenburg impactor. Mice treated the same way, but without the head impact served as controls (shams). We monitored body weight and core body temperature by infrared thermography and performed immunohistochemistry against c-Fos in various regions of the hypothalamus. We determined that a projectile velocity of 9 m/s significantly delayed recovery from the anesthesia without inducing skull fractures and signs of discomfort disappeared within 3 h, as assessed by grimace scale. Compared with shams, TBI mice displayed a rapid decrease in core body temperature which resolved within 48 h. Daily body weight gain was also significantly lower in TBI mice on the day following injury but recovered thereafter. c-Fos analysis revealed a significantly higher density of c-Fos-positive cells in the paraventricular nucleus and a significantly lower density in the median preoptic nucleus and medial preoptic area. We conclude that mild TBI induced by a single lateral head impact in mice at 9 m/s produces acute and reversible symptoms associated with hypothalamic dysfunction accompanied by significant changes in c-Fos expression within relevant areas of the hypothalamus. These findings support the hypothesis that a temporary alteration of neuronal activity may underlie the expression of reversible central autonomic and neuroendocrine symptoms. (© The Author(s) 2024. Published by Mary Ann Liebert, Inc.)
Databáze:	MEDLINE
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