Sensory systems: their impact on C. elegans survival

Abstract

Summary An animal’s survival strongly depends on a nervous system that can rapidly process and integrate the changing quality of its environment and promote the most appropriate physiological responses. This is amply demonstrated in the nematode worm Caenorhabditis elegans, where its sensory system has been shown to impact multiple physiological traits that range from behavior and developmental plasticity to longevity. Because of the accessibility of its nervous system and the number of tools available to study and manipulate its neural circuitry, C. elegans has thus become an important model organism in dissecting the mechanisms through which the nervous system promotes survival. Here we review our current understanding of how the C. elegans sensory system affects diverse physiological traits, whose coordination would be essential for survival under fluctuating environments. The knowledge we derive from the C. elegans studies should provide testable hypotheses in discovering similar mechanisms in higher animals.

Food-derived sensory cues modulate longevity via distinct neuroendocrine insulin-like peptides

“…ASJ lengthens life span at 20°C (Alcedo and Kenyon 2004) but shortens life span at the lower temperature of 15°C through the ILP INS-6 (this study). Together, these studies show that the neuronal effects on life span will involve different types of environmental cues (e.g., food-derived cues and temperature) (for review, see Allen et al 2015), which could change a neuron's local environment and thus its consequent effects on life span.…”

“…Sensory neurons will mediate many mechanisms, ranging from food level to food quality (Libert et al 2007;Maier et al 2010). Since we know that ILPs can have different activities in different physiological processes and have distinct neuronal expression patterns (for review, see Allen et al 2015 and references therein), certain ILPs may mediate the DR effects on life span, whereas other ILPs may mediate the non-DR effects on life span. However, it remains unclear how all of these ILPs will affect the activities of the IIS pathway.…”

“…These environmental changes are perceived by sensory neurons to elicit appropriate physiological responses for the optimal survival of animals. Sensory neurons also affect long-term physiological processes, such as development and metabolism (Bargmann 2006;Allen et al 2015). In addition, the sensory systems of Caenorhabditis elegans, Drosophila, and mice influence life span (Pletcher 2009;Jeong et al 2012;Riera et al 2014), although the molecular mechanisms involved are poorly understood.…”

Promoting Health and Longevity through Diet: From Model Organisms to Humans

“…Multiple neural, systemic, tissue-specific and cell autonomous mechanisms are involved (Figure 2). In both C. elegans and Drosophila , altered sensory perception alone may play a role, with specific subsets of sensory, including olfactory and gustatory, neurons influencing lifespan (Alcedo and Kenyon, 2004; Allen et al, 2014; Apfeld and Kenyon, 1999; Ostojic et al, 2014; Waterson et al, 2014). In C. elegans , Drosophila and mice, neural circuits both detect nutrient status and control the responses to it, in mice mediated mainly by the hypothalamus (Dacks et al, 2013).…”

Diet-responsive Transcriptional Regulation of Insulin in a Single Neuron Controls Systemic Metabolism

“…As in other organisms, Caenorhabditis elegans integrates diverse sensory inputs to formulate complex behavioural and metabolic decisions that best ensure survival and reproduction (reviewed in (Allen et al, 2015)). A leading example of this integrative process is how C. elegans spontaneously switch between three broad activity states: roaming, dwelling and quiescence (Ben Arous et al, 2009;Fujiwara et al, 2002;Hills et al, 2004;Shtonda and Avery, 2006).…”