The thrifty lipids: endocannabinoids and the neural control of energy conservation.
ABSTRACT The 'thrifty gene hypothesis' posits that evolution preferentially selects physiological mechanisms that optimize energy storage to increase survival under alternating conditions of abundance and scarcity of food. Recent experiments suggest that endocannabinoids - a class of lipid-derived mediators that activate cannabinoid receptors in many cells of the body - are key agents of energy conservation. The new evidence indicates that these compounds increase energy intake and decrease energy expenditure by controlling the activity of peripheral and central neural pathways involved in the sensing and hedonic processing of sweet and fatty foods, as well as in the storage of their energy content for future use.
- SourceAvailable from: Edgar Soria-Gómez[Show abstract] [Hide abstract]
ABSTRACT: Hunger arouses sensory perception, eventually leading to an increase in food intake, but the underlying mechanisms remain poorly understood. We found that cannabinoid type-1 (CB1) receptors promote food intake in fasted mice by increasing odor detection. CB1 receptors were abundantly expressed on axon terminals of centrifugal cortical glutamatergic neurons that project to inhibitory granule cells of the main olfactory bulb (MOB). Local pharmacological and genetic manipulations revealed that endocannabinoids and exogenous cannabinoids increased odor detection and food intake in fasted mice by decreasing excitatory drive from olfactory cortex areas to the MOB. Consistently, cannabinoid agonists dampened in vivo optogenetically stimulated excitatory transmission in the same circuit. Our data indicate that cortical feedback projections to the MOB crucially regulate food intake via CB1 receptor signaling, linking the feeling of hunger to stronger odor processing. Thus, CB1 receptor-dependent control of cortical feedback projections in olfactory circuits couples internal states to perception and behavior.Nature Neuroscience 02/2014; · 15.25 Impact Factor
Article: Is fat taste ready for primetime?[Show abstract] [Hide abstract]
ABSTRACT: Mounting evidence suggests that gustation is important for the orosensory detection of dietary fats, and might contribute to preferences that humans, rodents, and possibly other mammals exhibit for fat-rich foods. In contrast to sweet, sour, salty, bitter, and umami, fat is not widely recognized as a primary taste quality. Recent investigations, however, provide a wealth of information that is helping to elucidate the specific molecular, cellular, and neural mechanisms required for fat detection in mammals. The latest evidence supporting a fat taste will be explored in this review, with a particular focus on recent studies that suggest a surprising role for gut-brain endocannabinoid signaling in controlling intake and preference for fats based on their proposed taste properties.Physiology & Behavior 03/2014; · 3.16 Impact Factor
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ABSTRACT: Significant progress has been made in our understanding of how endogenous cannabinoids (eCBs) signal at excitatory and inhibitory synapses in the central nervous system (CNS). This review discusses how eCBs regulate inhibitory interneurons, their synapses, and the networks in which they are embedded. eCB signaling plays a pivotal role in brain physiology by means of their synaptic signal transduction, spatiotemporal signaling profile, routing of information through inhibitory microcircuits, and experience-dependent plasticity. Understanding the normal processes underlying eCB signaling is beginning to shed light on how their dysregulation contributes to disease.Current opinion in neurobiology 12/2013; 26C:42-50. · 7.21 Impact Factor