Title

Defective daily temperature regulation in a mouse model of amyotrophic lateral sclerosis

UMMS Affiliation

Department of Neurology; Program in Molecular Medicine; Department of Medicine, Division of Endocrinology, Metabolism, and Diabetes

Publication Date

2019-01-01

Document Type

Article

Disciplines

Nervous System | Nervous System Diseases | Neurology | Neuroscience and Neurobiology

Abstract

Current understanding of the pathogenesis of the familial form of amyotrophic lateral sclerosis has been aided by the study of transgenic mice that over-express mutated forms of the human CuZn-superoxide dismutase (SOD1) gene. While mutant SOD1 in motor neurons determines disease onset, other non-cell autonomous factors are critical for disease progression, and altered energy metabolism has been implicated as a contributing factor. Since most energy expended by laboratory mice is utilized to defend body temperature (Tb), we analyzed thermoregulation in transgenic mice carrying the G93A mutation of the human SOD1 gene, using implantable temperature data loggers to continuously record Tb for up to 85days. At room (22 degrees C) ambient temperature, G93A mice exhibited a diminished amplitude of the daily Tb rhythm compared to C57BL/6J controls, secondary to decreased Tb values during the dark (behaviorally active) phase of the light-dark cycle. The defect arose at 85-99days of age, around the age of symptom onset (as assessed by grip strength), well before observable weakness and weight loss, and could not be accounted for by decreased levels of locomotor activity or food consumption. Housing under thermoneutral (29 degrees C) ambient temperature partially rescued the defect, but age-dependently (only in animals > 100 days of age), suggesting that the deficit in older mice was due in part to inadequate thermogenesis by "peripheral" thermogenic organs as the disease progressed. In younger mice, we found that cold-induced thermogenesis and energy expenditure were intact, hinting that an initial "central" defect might localize to the subparaventricular zone, involving neural output pathways from the circadian clock in the hypothalamic suprachiasmatic nucleus to forebrain thermoregulatory circuitry.

Keywords

Circadian, G93A, SOD1, Scholander curves, Suprachiasmatic nucleus

DOI of Published Version

10.1016/j.expneurol.2018.07.008

Source

Exp Neurol. 2019 Jan;311:305-312. doi: 10.1016/j.expneurol.2018.07.008. Epub 2018 Jul 18. Link to article on publisher's site

Journal/Book/Conference Title

Experimental neurology

Related Resources

Link to Article in PubMed

PubMed ID

30031021

Share

COinS