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1.
J Dairy Sci ; 105(10): 8316-8327, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055855

RESUMO

Impoverished housing environments are thought to prevent motivated behaviors and may result in frustration. We first aimed to investigate an effective physical enrichment protocol to improve dairy calves' welfare and initially determine their use of various items. Thereafter, we aimed to determine dairy calves' preference for and ways of interacting with various items, and whether this was influenced by social housing. In experiment 1, at 21 ± 3 d of age, 27 individually housed calves were assigned alternately into 1 of 3 treatments: control (CON, no additional items), rotating enrichment (RE, one item each week on a rotating presentation schedule), and fixed enrichment (FE, 4 types of item at the same time). The items were stationary brushes, ropes, springs, nets filled with strawberry-scented hay, and dry teats. Calves' behaviors were observed from 4 to 7 wk of age using focal observations after feeding, followed by instantaneous scan sampling. Their behavioral responses to a novel object were assessed at 43 ± 1 d of age. In the instantaneous scans, calves in FE tended to interact with items more often than calves in RE. Calves in RE and FE expressed less non-nutritive oral behavior than those in CON. Latency to touch novel objects did not differ significantly between treatments. Calves in RE and FE interacted with nets filled with strawberry-scented hay more often than with other items in instantaneous scans. In experiment 2, 24 calves were assigned alternately into 8 individual pens and 8 pair pens at 2 d of age. All pens were provided with a stationary brush, plastic chain, net filled with strawberry-scented hay, and dry teat. Calves' behaviors were collected from 2 to 5 wk of age using instantaneous scan sampling. Calves interacted with nets filled with strawberry-scented hay more often than with other items. Pair housing reduced calves' interactions with items compared with individual housing. Individually and pair-housed calves' frequencies of overall interaction with items varied with time of day, with frequencies increasing to peaks at 0700, 1500, and 1900 h. Calves showed scratching, sniffing, sucking, butting, and hay intake toward nets filled with strawberry-scented hay and showed the first 3 behaviors toward stationary brushes, plastic chains, and dry teats. In conclusion, dairy calves are likely to prefer a fixed multi-item enrichment presentation schedule over a rotating schedule with a single enrichment item presented at one time. For the fixed multi-item enrichment presentation schedule, items were used more in individual pens than in pair pens, and a diurnal pattern was observed for use of the items. Nets filled with scented hay might be the most multifunctional and attractive item of the items tested.


Assuntos
Ingestão de Alimentos , Abrigo para Animais , Ração Animal/análise , Animais , Bovinos , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Plásticos , Desmame
2.
Probl Endokrinol (Mosk) ; 68(4): 78-91, 2022 Jun 01.
Artigo em Russo | MEDLINE | ID: mdl-36104969

RESUMO

The article provides a review of the current literature about time-restricted eating (TRE) as a new tool for the treatment of obesity and comorbid conditions. The search for new nutritional strategies in obesity, one of which is TRE, is due to the weak adherence of patients to hypocaloric diets in the long term, as well as the available data on the importance of -desynchronization of food intake with natural circadian rhythms in the development and progression of obesity and cardio--metabolic complications. The article describes the main mechanisms that regulate the circadian rhythms of food intake and nutrient absorption, substantiates the importance of adhering to a physiological diet for maintaining metabolic health. The main part of the review is devoted to reviewing the currently available researches on the effectiveness of various strategies of intermittent energy restriction for weight loss and the correction of metabolic parameters. Potential mechanisms of  the -effect of TRE on health are discussed, including those mediated by an unintentional decrease in caloric intake and changes in eating behavior, and differences in the effectiveness of early and late TRE. The article contains a detailed discussion of the potential problems and contradictions associated with the use of time-restricted eating in clinical practice, namely: the limitations and inconsistencies of the available clinical trials, the lack of data on long-term efficacy and safety, social and psychological limitations that impede the widespread use of TRE.


Assuntos
Obesidade , Redução de Peso , Dieta Redutora , Ingestão de Energia , Comportamento Alimentar/fisiologia , Humanos , Obesidade/terapia
3.
Philos Trans R Soc Lond B Biol Sci ; 377(1860): 20210302, 2022 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-35934961

RESUMO

Understanding the affective lives of animals has been a long-standing challenge in science. Recent technological progress in infrared thermal imaging has enabled researchers to monitor animals' physiological states in real-time when exposed to ecologically relevant situations, such as feeding in the company of others. During social feeding, an individual's physiological states are likely to vary with the nature of the resource and perceptions of competition. Previous findings in chimpanzees have indicated that events perceived as competitive cause decreases in nasal temperatures, whereas the opposite was observed for cooperative interactions. Here, we tested how food resources and audience structure impacted on how social feeding events were perceived by wild chimpanzees. Overall, we found that nasal temperatures were lower when meat was consumed as compared to figs, consistent with the idea that social feeding on more contested resources is perceived as more dangerous and stressful. Nasal temperatures were significant affected by interactions between food type and audience composition, in particular the number of males, their dominance status, and their social bond status relative to the subject, while no effects for the presence of females were observed. Our findings suggest that male chimpanzees closely monitor and assess their social environment during competitive situations, and that infrared imaging provides an important complement to access psychological processes beyond observable social behaviours. This article is part of the theme issue 'Cognition, communication and social bonds in primates'.


Assuntos
Comportamento Alimentar , Pan troglodytes , Animais , Cognição , Comportamento Alimentar/fisiologia , Feminino , Masculino , Pan troglodytes/fisiologia , Comportamento Social
4.
Addict Biol ; 27(5): e13206, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36001420

RESUMO

Chronic overeating is a core feature of diet-induced obesity. There is increasing evidence that in vulnerable individuals, such overeating could become compulsive, resembling an addictive disorder. The transition to compulsive substance use has been linked with changes at glutamatergic synapses in the nucleus accumbens. In this study, we investigated a potential link between such glutamatergic dysregulation and compulsive-like eating using a rat model of diet-induced obesity. A conditioned suppression task demonstrated that diet-induced obese rats display eating despite negative consequences, as their consumption was insensitive to an aversive cue. Moreover, nucleus accumbens expression of GluA1 and xCT proteins was upregulated in diet-induced obese animals. Lastly, both a computed 'addiction score' (based on performance across three criteria) and weight gain were positively correlated with changes in GluA1 and xCT expression in the nucleus accumbens. These data demonstrate that the propensity for diet-induced obesity is associated with compulsive-like eating of highly palatable food and is accompanied by 'addiction-like' glutamatergic dysregulation in the nucleus accumbens, thus providing neurobiological evidence of addiction-like pathology in this model of obesity.


Assuntos
Comportamento Aditivo , Comportamento Alimentar , Animais , Ingestão de Alimentos , Comportamento Alimentar/fisiologia , Hiperfagia , Obesidade , Ratos , Açúcares
5.
Arch Razi Inst ; 77(1): 141-149, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35891757

RESUMO

The current study was conducted to investigate the interaction between the central adrenergic and histaminergic systems and the broiler chick's feed intake. In the first experiment, the intracerebroventricular (ICV) injection of solutions was conducted which included 10 nmol of prazosin (an α1-receptor antagonist), 300 nmol of histamine, co-injection of prazosin and histamine. Experiments two to five were conducted similarly the same as the first experiment, in which chickens were ICV injected with 13 nmol of yohimbine (an α2-receptor antagonist), 24 nmol of metoprolol (a ß1 adrenergic receptor antagonist), 5 nmol of ICI 118,551 (a ß2 adrenergic receptor antagonist), and 20 nmol of SR 59230R (a ß3 adrenergic receptor antagonist). The injected solutions in the sixth experiment included 300 nmol of noradrenaline, 250 nmol of α-FMH (an alpha fluoromethyl histidine), noradrenaline, and α-FMH. Seventh to ninth experiments were similar to the sixth experiment, except that the chickens were ICV injected with 300 nmol of chlorpheniramine (a histamine H1 receptors antagonist), 82 nmol of famotidine (a histamine H2 receptors antagonist), and 300 nmol of thioperamide (a histamine H3 receptors antagonist), rather than α-FMH. Afterward, the cumulative food intake was measured 120 min after injection. Based on the obtained results, both histamine ICV injection and noradrenaline injection reduced food intake (P<0.05). Moreover, co-injection of histamine and ICI 118,551 (P<0.05), and co-injection of noradrenaline and Chlorpheniramine reduced food intake (P<0.05). In addition, noradrenaline and Thioperamide co-injection improved hypophagic effect of noradrenaline in neonatal chicken (P<0.05). These findings suggested the effect of interconnection between adrenergic and histaminergic systems, which may be mediated by H1 and H3 histaminergic and ß2 adrenergic receptors, on the regulation of food intake in the neonatal broiler chicken.


Assuntos
Apetite , Galinhas , Adrenérgicos/farmacologia , Antagonistas Adrenérgicos/farmacologia , Animais , Animais Recém-Nascidos , Clorfeniramina/farmacologia , Comportamento Alimentar/fisiologia , Histamina/farmacologia , Norepinefrina/farmacologia , Prazosina/farmacologia , Receptores Adrenérgicos , Receptores Histamínicos
6.
Microbiol Spectr ; 10(4): e0013622, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-35856906

RESUMO

Evidence is accumulating that plant viruses alter host plant traits in ways that modify their insect vectors' behavior. These alterations often enhance virus transmission, which has led to the hypothesis that these effects are manipulations caused by viral adaptation. However, we lack a mechanistic understanding of the genetic basis of these indirect, plant-mediated effects on vectors, their dependence on the plant host, and their relation to the mode of virus transmission. Transcriptome profiling of Arabidopsis thaliana and Camelina sativa plants infected with turnip yellows virus (TuYV) or cauliflower mosaic virus (CaMV) and infested with the common aphid vector Myzus persicae revealed strong virus- and host-specific differences in gene expression patterns. CaMV infection caused more severe effects on the phenotype of both plant hosts than did TuYV infection, and the severity of symptoms correlated strongly with the proportion of differentially expressed genes, especially photosynthesis genes. Accordingly, CaMV infection modified aphid behavior and fecundity more strongly than did infection with TuYV. Overall, infection with CaMV, relying on the noncirculative transmission mode, tends to have effects on metabolic pathways, with strong potential implications for insect vector-plant host interactions (e.g., photosynthesis, jasmonic acid, ethylene, and glucosinolate biosynthetic processes), while TuYV, using the circulative transmission mode, alters these pathways only weakly. These virus-induced deregulations of genes that are related to plant physiology and defense responses might impact both aphid probing and feeding behavior on infected host plants, with potentially distinct effects on virus transmission. IMPORTANCE Plant viruses change the phenotype of their plant hosts. Some of the changes impact interactions of the plant with insects that feed on the plants and transmit these viruses. These modifications may result in better virus transmission. We examine here the transcriptomes of two plant species infected with two viruses with different transmission modes to work out whether there are plant species-specific and transmission mode-specific transcriptome changes. Our results show that both are the case.


Assuntos
Afídeos , Arabidopsis , Vírus , Animais , Afídeos/genética , Arabidopsis/genética , Comportamento Alimentar/fisiologia , Perfilação da Expressão Gênica , Doenças das Plantas , Vírus/genética
7.
Nature ; 607(7920): 747-755, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35794476

RESUMO

When deciding what to eat, animals evaluate sensory information about food quality alongside multiple ongoing internal states1-10. How internal states interact to alter sensorimotor processing and shape decisions such as food choice remains poorly understood. Here we use pan-neuronal volumetric activity imaging in the brain of Drosophila melanogaster to investigate the neuronal basis of internal state-dependent nutrient appetites. We created a functional atlas of the ventral fly brain and find that metabolic state shapes sensorimotor processing across large sections of the neuropil. By contrast, reproductive state acts locally to define how sensory information is translated into feeding motor output. These two states thus synergistically modulate protein-specific food intake and food choice. Finally, using a novel computational strategy, we identify driver lines that label neurons innervating state-modulated brain regions and show that the newly identified 'borboleta' region is sufficient to direct food choice towards protein-rich food. We thus identify a generalizable principle by which distinct internal states are integrated to shape decision making and propose a strategy to uncover and functionally validate how internal states shape behaviour.


Assuntos
Drosophila melanogaster , Comportamento Alimentar , Animais , Drosophila melanogaster/fisiologia , Comportamento Alimentar/fisiologia , Preferências Alimentares , Lógica , Neurônios/fisiologia
8.
Elife ; 112022 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-35791902

RESUMO

Taste detection and hunger state dynamically regulate the decision to initiate feeding. To study how context-appropriate feeding decisions are generated, we combined synaptic resolution circuit reconstruction with targeted genetic access to specific neurons to elucidate a gustatory sensorimotor circuit for feeding initiation in adult Drosophila melanogaster. This circuit connects gustatory sensory neurons to proboscis motor neurons through three intermediate layers. Most neurons in this pathway are necessary and sufficient for proboscis extension, a feeding initiation behavior, and respond selectively to sugar taste detection. Pathway activity is amplified by hunger signals that act at select second-order neurons to promote feeding initiation in food-deprived animals. In contrast, the feeding initiation circuit is inhibited by a bitter taste pathway that impinges on premotor neurons, illuminating a local motif that weighs sugar and bitter taste detection to adjust the behavioral outcomes. Together, these studies reveal central mechanisms for the integration of external taste detection and internal nutritive state to flexibly execute a critical feeding decision.


Assuntos
Proteínas de Drosophila , Paladar , Animais , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/fisiologia , Comportamento Alimentar/fisiologia , Fome , Células Receptoras Sensoriais/fisiologia , Açúcares , Paladar/fisiologia
9.
Appetite ; 177: 106157, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35780936

RESUMO

Eating behaviors are shaped at an early age, persist into adulthood, and are implicated in the development of physical health outcomes, including obesity. Faster bite speed has been identified as an obesogenic eating behavior, prompting researchers to examine child and family factors associated with children's variability in bite speed. Child temperament, involving phenotypes of reactivity and regulation, and distractions in family food contexts are fruitful areas of investigation, but few studies have examined the interplay among these factors and their associations with bite speed. To address the gap in the literature, we examined relations between early child temperament, family mealtime distractions, and children's observed bite speed. Caregiver report of child temperament at 3 months was measured using the Infant Behavior Questionnaire Very Short Form - Revised. Child mealtime distractions and bite speed were assessed using family mealtime videos that were collected during home visits when children were 18-24 months of age (n = 109). Results revealed that children who were reported to be higher on orienting/regulation at 3 months, and who were more distracted during mealtimes at 18-24 months, had relatively slower bite speeds. No significant interactions were found. The findings from this correlational study inform further investigations into the implications of early temperament and food contexts for the development of eating behaviors implicated in obesity risk.


Assuntos
Comportamento Infantil , Temperamento , Criança , Comportamento Infantil/fisiologia , Comportamento Alimentar/fisiologia , Humanos , Refeições , Obesidade
10.
Nat Metab ; 4(7): 836-847, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35879462

RESUMO

The overconsumption of highly caloric and palatable foods has caused a surge in obesity rates in the past half century, thereby posing a healthcare challenge due to the array of comorbidities linked to heightened body fat accrual. Developing treatments to manage body weight requires a grasp of the neurobiological basis of appetite. In this Review, we discuss advances in neuroscience that have identified brain regions and neural circuits that coordinate distinct phases of eating: food procurement, food consumption, and meal termination. While pioneering work identified several hypothalamic nuclei to be involved in feeding, more recent studies have explored how neuronal populations beyond the hypothalamus, such as the mesolimbic pathway and nodes in the hindbrain, interconnect to modulate appetite. We also examine how long-term exposure to a calorically dense diet rewires feeding circuits and alters the response of motivational systems to food. Understanding how the nervous system regulates eating behaviour will bolster the development of medical strategies that will help individuals to maintain a healthy body weight.


Assuntos
Apetite , Comportamento Alimentar , Apetite/fisiologia , Peso Corporal , Dieta , Comportamento Alimentar/fisiologia , Humanos , Obesidade
11.
PLoS One ; 17(7): e0272236, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35905086

RESUMO

This study aimed to evaluate relationships among maternal residual feed intake (RFI) with growth performance and expression of genes involved in lipid metabolism in offspring of Nellore cattle. Fifty-three cows classified as negative or positive RFI by genomic prediction were exposed to fixed-time artificial insemination (FTAI) protocols at 2 and 3 years of age using semen from the same bull. In the first year, cows gestated under grazing conditions and nursed their calves in the feedlot. In the second year, the opposite occurred. Cows were weighed every 28 days during pregnancy and calves were weighed at birth and every 28 days until weaning. Ultrasound images were collected from the carcass of cows and calves. Muscle gene expression was evaluated in calves at birth and weaning. Data were analyzed by year considering the fixed effects of RFI class and FTAI protocol for variables measured in cows, and RFI class, FTAI protocol and sex for variables measured in calves. There was no effect of maternal RFI on calves performance in the first year. Lower expression of FABP4 gene and trend towards lower expression of SREBF1 and LPL genes were detected in samples collected after birth from calves born to negative RFI cows, indicating that adipogenesis was reduced during the fetal and neonatal period. In the second year, negative RFI cows had greater subcutaneous fat thickness than positive RFI cows, and their calves tended to be heavier at birth and to have less rump fat thickness at weaning. No significant differences in expression of genes studied were detected between cow RFI classes. Nellore cows classified as negative RFI consume less feed and produce calves whose growth potential is similar to that of calves produced by positive RFI cows.


Assuntos
Ração Animal , Comportamento Alimentar , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Feminino , Lipogênese/genética , Masculino , Músculos , Gravidez
12.
Nat Commun ; 13(1): 4229, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869064

RESUMO

Both rodents and primates have evolved to orchestrate food intake to maintain thermal homeostasis in coping with ambient temperature challenges. However, the mechanisms underlying temperature-coordinated feeding behavior are rarely reported. Here we find that a non-canonical feeding center, the anteroventral and periventricular portions of medial preoptic area (apMPOA) respond to altered dietary states in mice. Two neighboring but distinct neuronal populations in apMPOA mediate feeding behavior by receiving anatomical inputs from external and dorsal subnuclei of lateral parabrachial nucleus. While both populations are glutamatergic, the arcuate nucleus-projecting neurons in apMPOA can sense low temperature and promote food intake. The other type, the paraventricular hypothalamic nucleus (PVH)-projecting neurons in apMPOA are primarily sensitive to high temperature and suppress food intake. Caspase ablation or chemogenetic inhibition of the apMPOA→PVH pathway can eliminate the temperature dependence of feeding. Further projection-specific RNA sequencing and fluorescence in situ hybridization identify that the two neuronal populations are molecularly marked by galanin receptor and apelin receptor. These findings reveal unrecognized cell populations and circuits of apMPOA that orchestrates feeding behavior against thermal challenges.


Assuntos
Núcleo Arqueado do Hipotálamo , Núcleo Hipotalâmico Paraventricular , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Comportamento Alimentar/fisiologia , Hibridização in Situ Fluorescente , Camundongos , Núcleo Hipotalâmico Paraventricular/metabolismo , Temperatura
13.
Neurosci Biobehav Rev ; 139: 104760, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35780976

RESUMO

This review aims to draw attention to current studies on syndromes related to food eating behavior, including food addiction, and to highlight the neurobiological and neuropharmacological aspects of food addiction toward the development of new therapies. Food addiction and eating disorders are influenced by several neurobiological factors. Changes in feeding behavior, food addiction, and its pharmacological therapy are related to complex neurobiological processes in the brain. Thus, it is not surprising that there is inconsistency among various individual studies. In this review, we assessed literature including both experimental and clinical studies regarding food addiction as a feeding disorder. We selected articles from animal studies, randomized clinical trials, meta-analyses, narrative, and systemic reviews given that, crucial quantitative data with a measure of neurobiological, neuropharmacological aspects and current therapies of food addiction as an outcome. Thus, the main goal to outline here is to investigate and discuss the association between the brain reward system and feeding behavior in the frame of food addiction in the light of current literature.


Assuntos
Comportamento Alimentar , Dependência de Alimentos , Animais , Comportamento Alimentar/fisiologia , Dependência de Alimentos/tratamento farmacológico , Dependência de Alimentos/fisiopatologia , Humanos
14.
Am J Primatol ; 84(8): e23397, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35700311

RESUMO

The role of plant secondary metabolites (PSMs) in shaping the feeding decisions, habitat suitability, and reproductive success of herbivorous mammals has been a major theme in ecology for decades. Although primatologists were among the first to test these ideas, studies of PSMs in the feeding ecology of non-human primates have lagged in recent years, leading to a recent call for primatologists to reconnect with phytochemists to advance our understanding of the primate nutrition. To further this case, we present a formal meta-analysis of diet choice in response to PSMs based on field studies on wild primates. Our analysis of 155 measurements of primate feeding response to PSMs is drawn from 53 studies across 43 primate species which focussed primarily on the effect of three classes of PSMs tannins, phenolics, and alkaloids. We found a small but significant effect of PSMs on the diet choice of wild primates, which was largely driven by the finding that colobine primates showed a moderate aversion to condensed tannins. Conversely, there was no evidence that PSMs had a significant deterrent effect on food choices of non-colobine primates when all were combined into a single group. Furthermore, within the colobine primates, no other PSMs influenced feeding choices and we found no evidence that foregut anatomy significantly affected food choice with respect to PSMs. We suggest that methodological improvements related to experimental approaches and the adoption of new techniques including metabolomics are needed to advance our understanding of primate diet choice.


Assuntos
Comportamento Alimentar , Preferências Alimentares , Animais , Dieta/veterinária , Comportamento Alimentar/fisiologia , Mamíferos , Plantas/metabolismo , Primatas
15.
Nat Metab ; 4(6): 683-692, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35760867

RESUMO

Phospholipid levels are influenced by peripheral metabolism. Within the central nervous system, synaptic phospholipids regulate glutamatergic transmission and cortical excitability. Whether changes in peripheral metabolism affect brain lipid levels and cortical excitability remains unknown. Here, we show that levels of lysophosphatidic acid (LPA) species in the blood and cerebrospinal fluid are elevated after overnight fasting and lead to higher cortical excitability. LPA-related cortical excitability increases fasting-induced hyperphagia, and is decreased following inhibition of LPA synthesis. Mice expressing a human mutation (Prg-1R346T) leading to higher synaptic lipid-mediated cortical excitability display increased fasting-induced hyperphagia. Accordingly, human subjects with this mutation have higher body mass index and prevalence of type 2 diabetes. We further show that the effects of LPA following fasting are under the control of hypothalamic agouti-related peptide (AgRP) neurons. Depletion of AgRP-expressing cells in adult mice decreases fasting-induced elevation of circulating LPAs, as well as cortical excitability, while blunting hyperphagia. These findings reveal a direct influence of circulating LPAs under the control of hypothalamic AgRP neurons on cortical excitability, unmasking an alternative non-neuronal route by which the hypothalamus can exert a robust impact on the cortex and thereby affect food intake.


Assuntos
Diabetes Mellitus Tipo 2 , Proteína Relacionada com Agouti/genética , Proteína Relacionada com Agouti/metabolismo , Animais , Diabetes Mellitus Tipo 2/metabolismo , Comportamento Alimentar/fisiologia , Humanos , Hiperfagia/metabolismo , Lisofosfolipídeos/metabolismo , Lisofosfolipídeos/farmacologia , Camundongos , Neurônios/metabolismo , Sinapses/metabolismo
16.
J Neurophysiol ; 128(2): 302-309, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35730757

RESUMO

The nematode Caenorhabditis elegans uses rhythmic muscle contractions (pumps) of the pharynx, a tubular feeding organ, to filter, transport, and crush food particles. A number of feeding mutants have been identified, including those with slow pharyngeal pumping rate, weak muscle contraction, defective muscle relaxation, and defective grinding of bacteria. Many aspects of these pharyngeal behavioral defects and how they affect pharyngeal function are not well understood. For example, the behavioral deficits underlying inefficient particle transport in "slippery" mutants have been unclear. Here we use high-speed video microscopy to describe pharyngeal pumping behaviors and particle transport in wild-type animals and in feeding mutants. Different "slippery" mutants exhibit distinct defects including weak isthmus contraction, failure to trap particles in the anterior isthmus, and abnormal timing of contraction and relaxation in pharyngeal compartments. Our results show that multiple deficits in pharyngeal timing or contraction can cause defects in particle transport. NEW & NOTEWORTHY The nematode C. elegans uses rhythmic contractions of its pharynx (feeding organ) to filter, transport, and crush food bacteria. Genetic analyses have identified mutants with defective pharyngeal motions, but many details of these movements and how they affect feeding are poorly understood. We use high-speed video microscopy to describe pharyngeal pumping behaviors and particle transport in feeding mutants. We find that multiple deficits in pharyngeal timing or contraction can cause defects in particle transport.


Assuntos
Caenorhabditis elegans , Faringe , Animais , Caenorhabditis elegans/fisiologia , Comportamento Alimentar/fisiologia , Microscopia de Vídeo , Contração Muscular/fisiologia
17.
Nature ; 606(7915): 785-790, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35705806

RESUMO

Exercise confers protection against obesity, type 2 diabetes and other cardiometabolic diseases1-5. However, the molecular and cellular mechanisms that mediate the metabolic benefits of physical activity remain unclear6. Here we show that exercise stimulates the production of N-lactoyl-phenylalanine (Lac-Phe), a blood-borne signalling metabolite that suppresses feeding and obesity. The biosynthesis of Lac-Phe from lactate and phenylalanine occurs in CNDP2+ cells, including macrophages, monocytes and other immune and epithelial cells localized to diverse organs. In diet-induced obese mice, pharmacological-mediated increases in Lac-Phe reduces food intake without affecting movement or energy expenditure. Chronic administration of Lac-Phe decreases adiposity and body weight and improves glucose homeostasis. Conversely, genetic ablation of Lac-Phe biosynthesis in mice increases food intake and obesity following exercise training. Last, large activity-inducible increases in circulating Lac-Phe are also observed in humans and racehorses, establishing this metabolite as a molecular effector associated with physical activity across multiple activity modalities and mammalian species. These data define a conserved exercise-inducible metabolite that controls food intake and influences systemic energy balance.


Assuntos
Ingestão de Alimentos , Comportamento Alimentar , Obesidade , Fenilalanina , Condicionamento Físico Animal , Adiposidade/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Diabetes Mellitus Tipo 2 , Modelos Animais de Doenças , Ingestão de Alimentos/fisiologia , Metabolismo Energético , Comportamento Alimentar/fisiologia , Glucose/metabolismo , Ácido Láctico/metabolismo , Camundongos , Obesidade/metabolismo , Obesidade/prevenção & controle , Fenilalanina/administração & dosagem , Fenilalanina/análogos & derivados , Fenilalanina/metabolismo , Fenilalanina/farmacologia , Condicionamento Físico Animal/fisiologia
18.
Sci Rep ; 12(1): 9306, 2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35661783

RESUMO

For many animal species, knowing when to look for food may be as important as knowing where to look. Rats and other species use a feeding-responsive circadian timing mechanism to anticipate, behaviorally and physiologically, a predictable daily feeding opportunity. How this mechanism for anticipating a daily meal accommodates more than one predictable mealtime is unclear. Rats were trained to press a lever for food, and then limited to one or more daily meals at fixed or systematically varying times of day. The rats were able to anticipate up to 4 of 4 daily meals at fixed times of day and two 'daily' meals recurring at 24 h and 26 h intervals. When deprived of food, in constant dark, lever pressing recurred for multiple cycles at expected mealtimes, consistent with the periodicity of the prior feeding schedule. Anticipation did not require the suprachiasmatic nucleus circadian pacemaker. The anticipation rhythms could be simulated using a Kuramoto model in which clusters of coupled oscillators entrain to specific mealtimes based on initial phase and intrinsic circadian periodicity. A flexibly coupled system of food-entrainable circadian oscillators endows rats with adaptive plasticity in daily programming of foraging activity.


Assuntos
Ritmo Circadiano , Núcleo Supraquiasmático , Animais , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Alimentos , Privação de Alimentos/fisiologia , Ratos , Núcleo Supraquiasmático/fisiologia
19.
Trop Anim Health Prod ; 54(4): 203, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35676383

RESUMO

The objective of this study was to evaluate the feeding behavior of grazing steers supplemented in the dry season of the year. Thirty-two castrated crossbred (½ Holstein-Zebu) steers with an average initial weight of 378 ± 7.54 kg, aged 14 months, were distributed into four treatment groups in a completely randomized design with eight replicates. The animals were managed in an area covered with a pasture of Brachiaria brizantha cv. Marandu, in a rotational grazing system. The supplement was formulated so that the animals in the different treatment groups would ingest the same amount of crude protein (CP) daily. Thus, the treatments consisted of increasing levels of supplementation, based on the animals' body weight (BW), as the protein content of the supplement was reduced. The following treatments (dry matter basis) were tested: T2, supplement at 0.2% BW, with 50% CP; T4, supplement at 0.4% BW, with 25% CP; T6, supplement at 0.6% BW, with 16.67% CP; and T8, supplement at 0.8% BW, with 12.5% CP. Forage dry matter intake decreased linearly (P < 0.05), characterizing a substitution effect. The increasing supplementation levels influenced the animals' feeding behavior, especially grazing time, total feeding time, number of grazing bouts, and number of bites per day, which showed a positive quadratic response (P < 0.05), and rumination time, number of rumination bouts, number of cuds ruminated per day, and number of chews per ruminated cud, which exhibited a negative quadratic behavior (P < 0.05). Dry matter and neutral detergent fiber (NDF) feed efficiencies and dry matter and NDF rumination efficiencies responded quadratically (P < 0.05). In conclusion, concentrate supplementation at up to 0.8% BW improves the feeding behavior of grazing steers in terms of the intake of concentrate supplement and forage as well as the feed and rumination efficiencies.


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Ração Animal/análise , Animais , Dieta/veterinária , Fibras na Dieta/metabolismo , Suplementos Nutricionais , Digestão/fisiologia , Comportamento Alimentar/fisiologia , Estações do Ano
20.
J Physiol ; 600(12): 2877-2895, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35648134

RESUMO

The regulation of food intake and energy balance relies on the dynamic integration of exteroceptive and interoceptive signals monitoring nutritional, metabolic, cognitive, and emotional states. The paraventricular thalamus (PVT) is a central hub that, by integrating sensory, metabolic, and emotional states, may contribute to the regulation of feeding and homeostatic/allostatic processes. However, the underlying PVT circuits still remain elusive. Here, we aimed at unravelling the role of catecholaminergic (CA) inputs to the PVT in scaling feeding and metabolic efficiency. First, using region-specific retrograde disruption of CA projections, we show that PVT CA inputs mainly arise from the hindbrain, notably the locus coeruleus (LC) and the nucleus tractus solitarius. Second, taking advantage of integrative calorimetric measurements of metabolic efficiency, we reveal that CA inputs to the PVT scale adaptive feeding and metabolic responses in environmental, behavioural, physiological, and metabolic stress-like contexts. Third, we show that hindbrainTH →PVT inputs contribute to modulating the activity of PVT as well as lateral and dorsomedial hypothalamic neurons. In conclusion, the present study, by assessing the key role of CA inputs to the PVT in scaling homeostatic/allostatic regulations of feeding patterns, reveals the integrative and converging hindbrainTH →PVT paths that contribute to whole-body metabolic adaptations in stress-like contexts. KEY POINTS: The paraventricular thalamus (PVT) is known to receive projections from the hindbrain. Here, we confirm and further extend current knowledge on the existence of hindbrainTH →PVT catecholaminergic inputs, notably from the locus coeruleus and the nucleus tractus solitarius, with the nucleus tractus solitarius representing the main source. Disruption of hindbrainTH →PVT inputs contributes to the modulation of PVT neuron activity. HindbrainTH →PVT inputs scale feeding strategies in environmental, behavioural, physiological, and metabolic stress-like contexts. HindbrainTH →PVT inputs participate in regulating metabolic efficiency and nutrient partitioning in stress-like contexts. HindbrainTH →PVT inputs, directly and/or indirectly, contribute to modulating the downstream activity of lateral and dorsomedial hypothalamic neurons.


Assuntos
Núcleo Solitário , Tálamo , Comportamento Alimentar/fisiologia , Hipotálamo , Neurônios/fisiologia , Núcleo Hipotalâmico Paraventricular , Tálamo/fisiologia
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