Effect of intermittent chronic exposure to hypoxia on feeding behaviour of rats

Singh, Shashi Bala; Selvamurthy, W.

doi:10.1007/bf01387523

Cited by 18 publications

(7 citation statements)

References 15 publications

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“…Our results suggest that exposure to light at night might be exacerbating the negative effects of OSA on mood. Mice lost mass following IH treatment, consistent with previous studies indicating the validity of our IH model (15,39). IH increased adrenal gland masses consistent with a putative role played by the adrenal glands in IH-induced hypertension (13).…”

Section: Discussionsupporting

confidence: 89%

Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses

Aubrecht

Weil

Magalang

et al. 2013

American Journal of Physiology-Regulatory, Integrative and Comp

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Aubrecht TG, Weil ZM, Magalang UJ, Nelson RJ. Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses. Am J Physiol Regul Integr Comp Physiol 305: R78 -R86, 2013. First published May 8, 2013 doi:10.1152/ajpregu.00100.2013 and dim light at night (dLAN) have both been independently associated with alterations in mood and cognition. We aimed to determine whether dLAN would interact with intermittent hypoxia (IH), a condition characteristic of OSA, to alter the behavioral, cognitive, and affective responses. Adult male mice were housed in either standard lighting conditions (14:10-h light-dark cycle; 150 lux:0 lux) or dLAN (150 lux:5 lux). Mice were then exposed to IH (15 cycles/h, 8 h/day, FIO 2 nadir of 5%) for 3 wk, then tested in assays of affective and cognitive responses; brains were collected for dendritic morphology and PCR analysis. Exposure to dLAN and IH increased anxiety-like behaviors, as assessed in the open field, elevated plus maze, and the light/dark box. dLAN and IH increased depressive-like behaviors in the forced swim test. IH impaired learning and memory performance in the passive avoidance task; however, no differences were observed in spatial working memory, as assessed by y-maze or object recognition. IH combined with dLAN decreased cell body area in the CA1 and CA3 regions of the hippocampus. Overall, IH decreased apical spine density in the CA3, whereas dLAN decreased spine density in the CA1 of the hippocampus. TNF-␣ gene expression was not altered by IH or lighting condition, whereas VEGF expression was increased by dLAN. The combination of IH and dLAN provokes negative effects on hippocampal dendritic morphology, affect, and cognition, suggesting that limiting nighttime exposure to light in combination with other established treatments may be of benefit to patients with OSA.

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Section: Discussionsupporting

confidence: 89%

Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses

Aubrecht

Weil

Magalang

et al. 2013

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Despite comparable initial body weights for CIH and control rats (213 ± 4 g vs. 215 ± 6 g), after exposure to CIH, rats weighed significantly less than control rats (Table 2), likely to be due to a reduction in food intake (Singh & Selvamurthy, 1993). As shown previously in humans and rats (McGuire & Bradford, 1999; Silverberg et al 2002), exposure to CIH increased haematocrit (Table 2).…”

Section: Resultsmentioning

confidence: 99%

Altered sympathetic reflexes and vascular reactivity in rats after exposure to chronic intermittent hypoxia

Silva

Schreihofer

2011

The Journal of Physiology

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Exposure to chronic intermittent hypoxia (CIH) yields persistent elevations in sympathetic nerve activity (SNA) and mean arterial pressure(MAP)with exaggerated sympathetic chemoreflexes. We examined the impact of CIH upon other sympathoexcitatory reflexes and a potential central mechanism underlying the altered regulation of SNA.Male Sprague-Dawley rats were exposed to CIH for 2 weeks (40 s at 6% O2 every 9 min, 8 h day⁻¹). After exposure to CIH, urethane-anaesthetized, vagotomized, ventilated, paralysed rats had significantly elevated MAP, splanchnic SNA, and rate of phrenic nerve discharge (PND; P<0.05). Elimination of SNA by ganglionic blockade produced a larger fall in MAP in rats exposed to CIH (P<0.05). Like acute hypoxia, stimulation of the sciatic nerve or the nasal mucosa evoked greater increases in SNA after exposure to CIH (P<0.05). In addition, acute hypoxia promoted exaggerated increases in PND amplitude after CIH (P<0.05). In contrast, the nasopharyngeal reflex evoked exaggerated increases in SNA during apnoea. These sympathoexcitatory reflexes are mediated by glutamatergic activation of the rostral ventrolateral medulla (RVLM), and accordingly, microinjections of glutamate into RVLM evoked larger increases in SNA after CIH (P<0.05). Paradoxically, none of these exaggerated acute rises in SNA was accompanied by enhanced pressor responses. Reduced adrenergic vascular reactivity may contribute to the blunted sympathetically mediated pressor responses, because bolus doses of phenylephrine evoked attenuated pressor responses after CIH (P<0.01).These data suggest exposure to CIH facilitates activation of SNA, potentially by changes within the RVLM. However, the exaggerated rises in SNA are not dependent upon stimulation of inspiratory drive. Although elevated SNA may contribute to CIH-induced hypertension, reduced adrenergic vascular reactivity buffers the cardiovascular impact of exaggerated acute rises in SNA.

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“…The reduced solution intake could be because of induction of anhedonia in rats following exposure to hypoxia. Alternative explanation to the reduced sucrose solution intake could be induction of hypophagia following exposure to HH [6]. Thus, anhedonia could be a cause of hypophagia which in turn can induce loss of food intake and consequent decrease in body weight.…”

Section: Discussionmentioning

confidence: 99%

“…The stress has also reportedly been associated with sensory motor dysfunction [3] and loss of memory function on prolonged exposure [4,5]. Nausea, vomiting, hypophagia [6], dizziness and insomnia are the other problems encountered at high altitude. However, mental dysfunctions like the induction of prolonged state of confusion [7] and cognitive deficit on exposure to extreme altitude compel human to compromise with their performance that demands higher order mental functioning.…”

Section: Introductionmentioning

confidence: 99%

Exposure to Hypobaric Hypoxia and Reoxygenation Induces Transient Anxiety-Like Behavior in Rat

Baitharu¹,

Jain²,

Deep³

et al. 2013

JBBS

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Chronic exposure to hypobaric hypoxia (HH) causes memory impairment and prolonged state of mental confusion. However, effect of high altitude exposure on mood state and its underlying mechanisms have been poorly studied. Present study was undertaken to investigate the mood state alteration following chronic exposure to HH. Male Sprague Dawley rats were divided into five groups and exposed to hypoxia for 3, 7, 14 and 21 days in an animal decompression chamber at an altitude of 25,000ft. Anxiety-and depression-like behaviors were assessed by using various mazes along with changes in serotonin and glutamate level. Our study revealed a decrease in exploratory, grooming and rearing behavior in open field test following initial exposure to HH for 7 days without affecting the locomotory behavior. Initial exposure to HH-decreased time spent in open arm of elevated plus maze indicating induction of anxiety-like behavior which normalized on prolonged hypoxic exposure for 21 days. Hypoxic exposure for 7 days induced anhedonia and increased despair behavior in rat while there was steady improvement in these behaviors when exposed for 21 days. Decrease in serotonin level was noted in hippocampus along with elevated corticosterone and glutamate level which gradually decreased on prolonged exposure to HH. These findings suggest that initial exposure to HH increases transient anxiety-like behavior in rats followed by gradual improvement in mood state on prolonged exposure. Further, the study also indicates the involvement of serotonergic system in mood state alteration at high altitude following chronic exposure and reoxygenation.

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Effect of intermittent chronic exposure to hypoxia on feeding behaviour of rats

Cited by 18 publications

References 15 publications

Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses

Dim light at night interacts with intermittent hypoxia to alter cognitive and affective responses

Altered sympathetic reflexes and vascular reactivity in rats after exposure to chronic intermittent hypoxia

Exposure to Hypobaric Hypoxia and Reoxygenation Induces Transient Anxiety-Like Behavior in Rat

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