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Regulation of lifespan by chemosensory and thermosensory systems: findings in invertebrates and their implications in mammalian aging.

Jeong DE, Artan M, Seo K, Lee SJ - Front Genet (2012)

Bottom Line: Several studies have shown that chemosensory and thermosensory neurons affect the lifespan of invertebrate model animals, including Caenorhabditis elegans and Drosophila melanogaster.Although the mechanisms by which these sensory systems modulate lifespan are incompletely understood, hormonal signaling pathways have been implicated in sensory system-mediated lifespan regulation.In this review, we describe findings regarding how sensory nervous system components elicit physiological changes to regulate lifespan in invertebrate models, and discuss their implications in mammalian aging.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular and Life Science, Pohang University of Science and Technology Pohang, South Korea.

ABSTRACT
Many environmental factors that dynamically change in nature influence various aspects of animal physiology. Animals are equipped with sensory neuronal systems that help them properly sense and respond to environmental factors. Several studies have shown that chemosensory and thermosensory neurons affect the lifespan of invertebrate model animals, including Caenorhabditis elegans and Drosophila melanogaster. Although the mechanisms by which these sensory systems modulate lifespan are incompletely understood, hormonal signaling pathways have been implicated in sensory system-mediated lifespan regulation. In this review, we describe findings regarding how sensory nervous system components elicit physiological changes to regulate lifespan in invertebrate models, and discuss their implications in mammalian aging.

No MeSH data available.


Related in: MedlinePlus

Hypothetical model of longevity and hibernation modulation by thermoregulation in mammals. Ambient temperature decrease is sensed by cold-activated receptors and transmitted to the POA of the hypothalamus. Neuropeptides such as somatostatin may be secreted to inhibit growth, cellular proliferation, body core temperature, oxygen consumption, and metabolic activities by decreasing the levels of growth hormone, thyroid-stimulating hormone (TSH) and/or serotonin. These changes appear to contribute to the hibernation process and may influence longevity.
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Figure 5: Hypothetical model of longevity and hibernation modulation by thermoregulation in mammals. Ambient temperature decrease is sensed by cold-activated receptors and transmitted to the POA of the hypothalamus. Neuropeptides such as somatostatin may be secreted to inhibit growth, cellular proliferation, body core temperature, oxygen consumption, and metabolic activities by decreasing the levels of growth hormone, thyroid-stimulating hormone (TSH) and/or serotonin. These changes appear to contribute to the hibernation process and may influence longevity.

Mentions: What are the potential molecular mechanisms behind the beneficial effects of hibernation on health and longevity? Recent research using the Djungarian hamster Phodopus sungorus suggests that changes in relative telomere length (RTL) may underlie the potential benefits of hibernation (Turbill et al., 2011). Djungarian hamsters use daily torpor, which can be considered as temporary hibernation, upon exposure to winter conditions for over 180 days. Animals that are kept at cold temperature (9°C) and use daily torpor have increased RTL compared to animals kept at warm temperature (20°C). Therefore, the use of daily torpor may delay aging during harsh environmental conditions by increasing telomere length in hamsters. Other studies suggest that endocrine signaling plays a role in hibernation and perhaps the longevity associated with it. The level of neuropeptide somatostatin, a negative regulator of growth hormone and thyroid-stimulating hormone (TSH) (Tichomirowa et al., 2005), increases before hibernation in the golden-mantled squirrel Spermaphilus lateralis (Muchlinski et al., 1983). Interestingly, growth hormone knock-out mice have long lifespan (Coschigano et al., 2000), significantly reduced levels of thyroid hormone, and decreased body core temperature compared to normal mice (Hauck et al., 2001). In addition, Ames dwarf mice, which are deficient in growth hormone, TSH, and prolactin, are long lived (Brown-Borg et al., 1996). A recent study suggests that growth hormone receptor deficiency in humans is associated with reduced incidences of age-related diseases, including cancer and diabetes (Guevara-Aguirre et al., 2011). Collectively, one can speculate that before the onset of hibernation, somatostatin inhibits growth hormone and TSH secretion, leading to lifespan extension (Figure 5).


Regulation of lifespan by chemosensory and thermosensory systems: findings in invertebrates and their implications in mammalian aging.

Jeong DE, Artan M, Seo K, Lee SJ - Front Genet (2012)

Hypothetical model of longevity and hibernation modulation by thermoregulation in mammals. Ambient temperature decrease is sensed by cold-activated receptors and transmitted to the POA of the hypothalamus. Neuropeptides such as somatostatin may be secreted to inhibit growth, cellular proliferation, body core temperature, oxygen consumption, and metabolic activities by decreasing the levels of growth hormone, thyroid-stimulating hormone (TSH) and/or serotonin. These changes appear to contribute to the hibernation process and may influence longevity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475297&req=5

Figure 5: Hypothetical model of longevity and hibernation modulation by thermoregulation in mammals. Ambient temperature decrease is sensed by cold-activated receptors and transmitted to the POA of the hypothalamus. Neuropeptides such as somatostatin may be secreted to inhibit growth, cellular proliferation, body core temperature, oxygen consumption, and metabolic activities by decreasing the levels of growth hormone, thyroid-stimulating hormone (TSH) and/or serotonin. These changes appear to contribute to the hibernation process and may influence longevity.
Mentions: What are the potential molecular mechanisms behind the beneficial effects of hibernation on health and longevity? Recent research using the Djungarian hamster Phodopus sungorus suggests that changes in relative telomere length (RTL) may underlie the potential benefits of hibernation (Turbill et al., 2011). Djungarian hamsters use daily torpor, which can be considered as temporary hibernation, upon exposure to winter conditions for over 180 days. Animals that are kept at cold temperature (9°C) and use daily torpor have increased RTL compared to animals kept at warm temperature (20°C). Therefore, the use of daily torpor may delay aging during harsh environmental conditions by increasing telomere length in hamsters. Other studies suggest that endocrine signaling plays a role in hibernation and perhaps the longevity associated with it. The level of neuropeptide somatostatin, a negative regulator of growth hormone and thyroid-stimulating hormone (TSH) (Tichomirowa et al., 2005), increases before hibernation in the golden-mantled squirrel Spermaphilus lateralis (Muchlinski et al., 1983). Interestingly, growth hormone knock-out mice have long lifespan (Coschigano et al., 2000), significantly reduced levels of thyroid hormone, and decreased body core temperature compared to normal mice (Hauck et al., 2001). In addition, Ames dwarf mice, which are deficient in growth hormone, TSH, and prolactin, are long lived (Brown-Borg et al., 1996). A recent study suggests that growth hormone receptor deficiency in humans is associated with reduced incidences of age-related diseases, including cancer and diabetes (Guevara-Aguirre et al., 2011). Collectively, one can speculate that before the onset of hibernation, somatostatin inhibits growth hormone and TSH secretion, leading to lifespan extension (Figure 5).

Bottom Line: Several studies have shown that chemosensory and thermosensory neurons affect the lifespan of invertebrate model animals, including Caenorhabditis elegans and Drosophila melanogaster.Although the mechanisms by which these sensory systems modulate lifespan are incompletely understood, hormonal signaling pathways have been implicated in sensory system-mediated lifespan regulation.In this review, we describe findings regarding how sensory nervous system components elicit physiological changes to regulate lifespan in invertebrate models, and discuss their implications in mammalian aging.

View Article: PubMed Central - PubMed

Affiliation: Division of Molecular and Life Science, Pohang University of Science and Technology Pohang, South Korea.

ABSTRACT
Many environmental factors that dynamically change in nature influence various aspects of animal physiology. Animals are equipped with sensory neuronal systems that help them properly sense and respond to environmental factors. Several studies have shown that chemosensory and thermosensory neurons affect the lifespan of invertebrate model animals, including Caenorhabditis elegans and Drosophila melanogaster. Although the mechanisms by which these sensory systems modulate lifespan are incompletely understood, hormonal signaling pathways have been implicated in sensory system-mediated lifespan regulation. In this review, we describe findings regarding how sensory nervous system components elicit physiological changes to regulate lifespan in invertebrate models, and discuss their implications in mammalian aging.

No MeSH data available.


Related in: MedlinePlus