Reduced brown adipose tissue thermogenesis during environmental interactions in transgenic rats with ataxin-3-mediated ablation of hypothalamic orexin neurons

2014 ◽  
Vol 307 (8) ◽  
pp. R978-R989 ◽  
Author(s):  
Mazher Mohammed ◽  
Youichirou Ootsuka ◽  
Masashi Yanagisawa ◽  
William Blessing
Keyword(s):  
Adipose Tissue ◽  
Body Temperature ◽  
Brown Adipose Tissue ◽  
Activity Cycle ◽  
Time Interval ◽  
Transgenic Rats ◽  
Environmental Interactions ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Environmental Events

Thermogenesis in brown adipose tissue (BAT) contributes to substantial increases in body temperature evoked by threatening or emotional stimuli. BAT thermogenesis also contributes to increases in body temperature that occur during active phases of the basic rest-activity cycle (BRAC), as part of normal daily life. Hypothalamic orexin-synthesizing neurons influence many physiological and behavioral variables, including BAT and body temperature. In conscious unrestrained animals maintained for 3 days in a quiet environment (24–26°C) with ad libitum food and water, we compared temperatures in transgenic rats with ablation of orexin neurons induced by expression of ataxin-3 (Orx_Ab) with wild-type (WT) rats. Both baseline BAT temperature and baseline body temperature, measured at the onset of BRAC episodes, were similar in Orx_Ab and WT rats. The time interval between BRAC episodes was also similar in the two groups. However, the initial slopes and amplitudes of BRAC-related increases in BAT and body temperature were reduced in Orx_Ab rats. Similarly, the initial slopes and amplitudes of the increases in BAT temperatures induced by sudden exposure to an intruder rat (freely moving or confined to a small cage) or by sudden exposure to live cockroaches were reduced in resident Orx_Ab rats. Constriction of the tail artery induced by salient alerting stimuli was also reduced in Orx_Ab rats. Our results suggest that orexin-synthesizing neurons contribute to the intensity with which rats interact with the external environment, both when the interaction is “spontaneous” and when the interaction is provoked by threatening or salient environmental events.

Food restriction increases torpor and improves brown adipose tissue thermogenesis in ob/ob mice

1985 ◽  
Vol 248 (5) ◽  
pp. E531-E539 ◽  
Author(s):  
J. Himms-Hagen
Keyword(s):  
Adipose Tissue ◽  
Body Temperature ◽  
Brown Adipose Tissue ◽  
Rectal Temperature ◽  
Food Restriction ◽  
Normal Body Temperature ◽  
Cold Intolerance ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Ad Libitum

Restricting the food intake of the genetically obese (ob/ob) mouse is known to ameliorate its cold intolerance. Cold intolerance of the ob/ob mouse is associated with defective thermogenesis in its brown adipose tissue. The objective of the experiments was to find out whether food restriction could increase the thermogenic function of brown adipose tissue of the ob/ob mouse. Obese and lean mice were fed a restricted amount of chow in one meal per day for 3-7 mo. Both lean and ob/ob mice were torpid (rectal temperature of approximately 32 degrees C) in the early morning and aroused spontaneously to a normal body temperature before the anticipated meal time. Obese mice were also torpid during the dark phase, whereas lean mice were active and had a normal body temperature at this time. Brown adipose tissue was in a thermogenically inactive state (low level of mitochondrial GDP binding) in torpid lean and ob/ob mice but became thermogenically active (increase in mitochondrial GDP binding) during stimulated arousal when body temperature increased by 6-7 degrees C in 15-30 min. Ad libitum-fed ob/ob mice had a normal diurnal rhythm in a rectal temperature that was at a lower level than in lean ad libitum-fed mice. They did not raise their rectal temperatures when stimulated and no activation of brown adipose tissue thermogenesis occurred under these conditions. Food restriction increased the capacity of both lean and ob/ob mice to raise their metabolic rate in response to injection of noradrenaline, indicating an increased capacity for thermogenesis in their brown adipose tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Central Pathways Controlling Brown Adipose Tissue Thermogenesis

Physiology ◽  
2004 ◽  
Vol 19 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Shaun F. Morrison
Keyword(s):  
Adipose Tissue ◽  
Energy Balance ◽  
Body Temperature ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Functional Organization ◽  
Sympathetic Outflow ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
Central Network

Heat production in brown adipose tissue contributes to cold defense, to stress-induced increases in body temperature, and to energy balance. Elucidating the functional organization of the central network controlling the sympathetic outflow to brown adipose tissue could provide a framework for understanding how dysregulation of thermogenesis contributes to hyperthermia and to obesity.

scholarly journals Brown adipose tissue thermogenesis heats brain and body as part of the brain-coordinated ultradian basic rest-activity cycle

Neuroscience ◽  
2009 ◽  
Vol 164 (2) ◽  
pp. 849-861 ◽  
Author(s):  
Y. Ootsuka ◽  
R.C. de Menezes ◽  
D.V. Zaretsky ◽  
A. Alimoradian ◽  
J. Hunt ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Activity Cycle ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis ◽  
The Brain ◽  
Rest Activity

Brown adipose tissue thermogenesis in women with polycystic ovary syndrome

2017 ◽  
Author(s):  
Soulmaz Shorakae ◽  
Eveline Jona ◽  
Courten Barbora de ◽  
Gavin Lambert ◽  
Elisabeth Lambert ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Polycystic Ovary Syndrome ◽  
Brown Adipose Tissue ◽  
Polycystic Ovary ◽  
Ovary Syndrome ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis

scholarly journals Stimulatory, but not anxiogenic, doses of caffeine act centrally to activate interscapular brown adipose tissue thermogenesis in anesthetized male rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Van Schaik ◽  
C. Kettle ◽  
R. Green ◽  
W. Sievers ◽  
M. W. Hale ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Basolateral Amygdala ◽  
Free Breathing ◽  
Male Rats ◽  
Central Administration ◽  
Hypothalamic Area ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Brown Adipose Tissue Thermogenesis

AbstractThe role of central orexin in the sympathetic control of interscapular brown adipose tissue (iBAT) thermogenesis has been established in rodents. Stimulatory doses of caffeine activate orexin positive neurons in the lateral hypothalamus, a region of the brain implicated in stimulating BAT thermogenesis. This study tests the hypothesis that central administration of caffeine is sufficient to activate BAT. Low doses of caffeine administered either systemically (intravenous [IV]; 10 mg/kg) and centrally (intracerebroventricular [ICV]; 5–10 μg) increases BAT thermogenesis, in anaesthetised (1.5 g/kg urethane, IV) free breathing male rats. Cardiovascular function was monitored via an indwelling intra-arterial cannula and exhibited no response to the caffeine. Core temperature did not significantly differ after administration of caffeine via either route of administration. Caffeine administered both IV and ICV increased neuronal activity, as measured by c-Fos-immunoreactivity within subregions of the hypothalamic area, previously implicated in regulating BAT thermogenesis. Significantly, there appears to be no neural anxiety response to the low dose of caffeine as indicated by no change in activity in the basolateral amygdala. Having measured the physiological correlate of thermogenesis (heat production) we have not measured indirect molecular correlates of BAT activation. Nevertheless, our results demonstrate that caffeine, at stimulatory doses, acting via the central nervous system can increase thermogenesis, without adverse cardio-dynamic impact.

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