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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.


Model of lifespan control by chemosensation and insulin/IGF-1 signaling in C. elegans. A subset of ciliated neurons in the head region (for example, in the amphid) perceive chemosensory cues and trigger signal transduction cascades. Upon binding to ligands, chemosensory G protein-coupled receptors (GPCRs) activate G proteins, which lead to cGMP production. This in turn opens cyclic nucleotide-gated channels and increases Ca2+ and Na+ influx. Inhibiting chemosensory neuronal structure or function in specific neurons may alter neuroendocrine signaling and reduces insulin/IGF-1 signaling, which activates the DAF-16/FOXO transcription factor and promotes longevity.
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Figure 2: Model of lifespan control by chemosensation and insulin/IGF-1 signaling in C. elegans. A subset of ciliated neurons in the head region (for example, in the amphid) perceive chemosensory cues and trigger signal transduction cascades. Upon binding to ligands, chemosensory G protein-coupled receptors (GPCRs) activate G proteins, which lead to cGMP production. This in turn opens cyclic nucleotide-gated channels and increases Ca2+ and Na+ influx. Inhibiting chemosensory neuronal structure or function in specific neurons may alter neuroendocrine signaling and reduces insulin/IGF-1 signaling, which activates the DAF-16/FOXO transcription factor and promotes longevity.

Mentions: Chemosensation is initiated by the detection of chemical cues by receptors in chemosensory neurons that form neural circuits with other neurons (Bargmann, 2006). Chemosensory neural circuits include motor neurons; therefore, the organism's sensory system can elicit behavioral responses to environmental stimuli. Model invertebrates with relatively simple nervous systems have been utilized to genetically dissect functions and mechanisms of chemosensory systems. One of them is the nematode C. elegans, a simple multi-cellular animal that lives in decomposing organic material. Approximately 60 of the 302 C. elegans neurons are ciliated sensory neurons, including chemosensory neurons, some of which are in the amphid organ in the head (Bargmann, 2006) (Figure 2). Chemosensory signals are transduced by many effector proteins in the neurons, including G protein-coupled receptors (GPCRs) that are activated by binding with their ligands (Figure 2). GPCRs activate G protein signaling to influence the level of cyclic GMP (cGMP), which functions as a second messenger for the chemosensory signal transduction. cGMP binds to and opens cyclic nucleotide-gated channels to regulate cation flux that is required for chemosensation (Bargmann, 2006).


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)

Model of lifespan control by chemosensation and insulin/IGF-1 signaling in C. elegans. A subset of ciliated neurons in the head region (for example, in the amphid) perceive chemosensory cues and trigger signal transduction cascades. Upon binding to ligands, chemosensory G protein-coupled receptors (GPCRs) activate G proteins, which lead to cGMP production. This in turn opens cyclic nucleotide-gated channels and increases Ca2+ and Na+ influx. Inhibiting chemosensory neuronal structure or function in specific neurons may alter neuroendocrine signaling and reduces insulin/IGF-1 signaling, which activates the DAF-16/FOXO transcription factor and promotes longevity.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: Model of lifespan control by chemosensation and insulin/IGF-1 signaling in C. elegans. A subset of ciliated neurons in the head region (for example, in the amphid) perceive chemosensory cues and trigger signal transduction cascades. Upon binding to ligands, chemosensory G protein-coupled receptors (GPCRs) activate G proteins, which lead to cGMP production. This in turn opens cyclic nucleotide-gated channels and increases Ca2+ and Na+ influx. Inhibiting chemosensory neuronal structure or function in specific neurons may alter neuroendocrine signaling and reduces insulin/IGF-1 signaling, which activates the DAF-16/FOXO transcription factor and promotes longevity.
Mentions: Chemosensation is initiated by the detection of chemical cues by receptors in chemosensory neurons that form neural circuits with other neurons (Bargmann, 2006). Chemosensory neural circuits include motor neurons; therefore, the organism's sensory system can elicit behavioral responses to environmental stimuli. Model invertebrates with relatively simple nervous systems have been utilized to genetically dissect functions and mechanisms of chemosensory systems. One of them is the nematode C. elegans, a simple multi-cellular animal that lives in decomposing organic material. Approximately 60 of the 302 C. elegans neurons are ciliated sensory neurons, including chemosensory neurons, some of which are in the amphid organ in the head (Bargmann, 2006) (Figure 2). Chemosensory signals are transduced by many effector proteins in the neurons, including G protein-coupled receptors (GPCRs) that are activated by binding with their ligands (Figure 2). GPCRs activate G protein signaling to influence the level of cyclic GMP (cGMP), which functions as a second messenger for the chemosensory signal transduction. cGMP binds to and opens cyclic nucleotide-gated channels to regulate cation flux that is required for chemosensation (Bargmann, 2006).

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.