scholarly journals Thirst interneurons that promote water seeking and limit feeding behavior in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Dan Landayan ◽  
Brian P Wang ◽  
Jennifer Zhou ◽  
Fred W Wolf

Thirst is a motivational state that drives behaviors to obtain water for fluid homeostasis. We identified two types of central brain interneurons that regulate thirsty water seeking in Drosophila, that we term the Janu neurons. Janu-GABA, a local interneuron in the subesophageal zone, is activated by water deprivation and is specific to thirsty seeking. Janu-AstA projects from the subesophageal zone to the superior medial protocerebrum, a higher order processing area. Janu-AstA signals with the neuropeptide Allatostatin A to promote water seeking and to inhibit feeding behavior. NPF (Drosophila NPY) neurons are postsynaptic to Janu-AstA for water seeking and feeding through the AstA-R2 galanin-like receptor. NPF neurons use NPF to regulate thirst and hunger behaviors. Flies choose Janu neuron activation, suggesting that thirsty seeking up a humidity gradient is rewarding. These findings identify novel central brain circuit elements that coordinate internal state drives to selectively control motivated seeking behavior.

2020 ◽  
Author(s):  
Younghee Lee ◽  
Ha Young Song ◽  
You Bin Kim ◽  
Kyu Sik Kim ◽  
Dong-Soo Ha ◽  
...  

1.AbstractAgouti-related protein (AgRP) has been believed to be the main driver of feeding behaviors ever since its discovery. However, recent studies using fiber photometry and optogenetics proved that feeding behaviors are not directly driven by AgRP neurons (temporal discrepancy between neuronal activity and behavior). To resolve this paradox, we conducted novel multi-phase feeding experiments to scrutinize the dynamics of AgRP. Fiber photometry study showed that AgRP neurons start to deactivate even before the initiation of the food search phase. Using optogenetics, we could prove that the feeding behavior induced by AgRP neuron activation had substantial temporal delay and the feeding behavior was sustained for substantial time even after cessation of optogenetic activation. These results indicate that AgRP neurons are not the direct driver of feeding behavior and another downstream neuron is the driver of feeding behavior. Leptin receptor (LepR) neurons in the lateral hypothalamus (LH). LH LepR neurons were activated before voluntary food search behavior initiation and showed robust increase after food approach behavior. Artificial activation of LH LepR neurons drives food search and food approach behavior. In accordance, chemogenetic activation of LepR neurons increased food search and food approach behaviors. Lastly, slice calcium imaging results showed the possibility that NPY from the AgRP neurons could be the downstream neuromodulator of AgRP neuron, driving LH LepR neuron activation. Overall, our study shows that AgRP neurons are not the direct drivers of feeding behavior, whereas LH LepR neurons directly drive sustained food seeking behavior.


2021 ◽  
pp. 074873042110458
Author(s):  
Carson V. Fulgham ◽  
Austin P. Dreyer ◽  
Anita Nasseri ◽  
Asia N. Miller ◽  
Jacob Love ◽  
...  

Many behaviors exhibit ~24-h oscillations under control of an endogenous circadian timing system that tracks time of day via a molecular circadian clock. In the fruit fly, Drosophila melanogaster, most circadian research has focused on the generation of locomotor activity rhythms, but a fundamental question is how the circadian clock orchestrates multiple distinct behavioral outputs. Here, we have investigated the cells and circuits mediating circadian control of feeding behavior. Using an array of genetic tools, we show that, as is the case for locomotor activity rhythms, the presence of feeding rhythms requires molecular clock function in the ventrolateral clock neurons of the central brain. We further demonstrate that the speed of molecular clock oscillations in these neurons dictates the free-running period length of feeding rhythms. In contrast to the effects observed with central clock cell manipulations, we show that genetic abrogation of the molecular clock in the fat body, a peripheral metabolic tissue, is without effect on feeding behavior. Interestingly, we find that molecular clocks in the brain and fat body of control flies gradually grow out of phase with one another under free-running conditions, likely due to a long endogenous period of the fat body clock. Under these conditions, the period of feeding rhythms tracks with molecular oscillations in central brain clock cells, consistent with a primary role of the brain clock in dictating the timing of feeding behavior. Finally, despite a lack of effect of fat body selective manipulations, we find that flies with simultaneous disruption of molecular clocks in multiple peripheral tissues (but with intact central clocks) exhibit decreased feeding rhythm strength and reduced overall food intake. We conclude that both central and peripheral clocks contribute to the regulation of feeding rhythms, with a particularly dominant, pacemaker role for specific populations of central brain clock cells.


2021 ◽  
Author(s):  
Pierre-Yves Musso ◽  
Pierre Junca ◽  
Michael D Gordon

ABSTRACTIngestion of certain sugars leads to activation of fructose sensors within the brain of flies, which then sustain or terminate feeding behavior depending on internal state. Here, we describe a three-part neural circuit that links satiety with fructose sensing. We show that AB-FBl8 neurons of the Fan-shaped body display oscillatory calcium activity when hemolymph glycemia is high, and that these oscillations require synaptic input from SLP-AB neurons projecting from the protocerebrum to the asymmetric body. Suppression of activity in this circuit, either by starvation or genetic silencing, promotes specific drive for fructose ingestion. Moreover, neuropeptidergic signaling by tachykinin bridges fan-shaped body activity and Gr43a-mediated fructose sensing. Together, our results demonstrate how a three-layer neural circuit links the detection of two sugars to impart precise satiety-dependent control over feeding behavior.


2015 ◽  
Vol 112 (40) ◽  
pp. E5523-E5532 ◽  
Author(s):  
Peter T. Weir ◽  
Michael H. Dickinson

Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit.


2008 ◽  
Vol 295 (5) ◽  
pp. R1415-R1424 ◽  
Author(s):  
Michael S. Smirnov ◽  
Eugene A. Kiyatkin

We examined the pattern of temperature fluctuations in the nucleus accumbens (NAcc), temporal muscle, and skin, along with locomotion in food-deprived and nondeprived rats following the presentation of an open or closed food container and during subsequent eating or food-seeking behavior without eating. Although rats in food-deprived, quiet resting conditions had more than twofold lower spontaneous locomotion and lower temperature values than in nondeprived conditions, after presentation of a container, they consistently displayed food-seeking behavior, showing much larger and longer temperature changes. When the container was open, rats rapidly retrieved food and consumed it. Food consumption was preceded and accompanied by gradual increases in brain and muscle temperatures (∼1.5°C) and a weaker, delayed increase in skin temperature (∼0.8°C). All temperatures began to rapidly fall immediately after eating was completed, but NAcc and muscle temperatures returned to baseline after ∼35 min. When the container was closed and rats were unable to obtain food, they continued food-seeking activity during the entire period of presentation. Similar to eating, this activity was preceded and accompanied by gradual temperature increases in the brain and muscle, which were somewhat smaller than those during eating (∼1.2°C), with no changes in skin temperature. In contrast to trials with eating, NAcc and muscle temperatures continued to increase for ∼10 min after the container was removed from the cage and the rat continued food-seeking behavior, with a return to baselines after ∼50 min. These temperature fluctuations are discussed with respect to alterations in metabolic brain activity associated with feeding behavior, depending upon deprivation state and food availability.


2021 ◽  
Author(s):  
Lénie Torregrossa ◽  
Amad Amedy ◽  
Jacqueline Roig ◽  
Andrea Prada ◽  
Sohee Park

Though bodily self-disturbances are well documented in schizophrenia, interoceptive functioning (i.e., the perception of the internal state of the body) remains poorly understood in this population. In fact, only two studies to date have empirically measured interoceptive ability in schizophrenia. Both studies documented a deficit in interoceptive accuracy (i.e., objective performance on a heartbeat detection task), and one noted differences in interoceptive sensibility (i.e., subjective experience of interoception) in this population. To our knowledge, interoceptive awareness (i.e., metacognitive awareness of one’s interoceptive ability) has never been measured in schizophrenia and the link between interoceptive functioning and schizotypy remains unexplored. The present study addresses this gap by investigating the three dimensions of interoception in individuals with schizophrenia and matched controls (Experiment 1, N=58) and across the schizotypy spectrum (Experiment 2, N=109). Consistent with the literature, Experiment 1 documented a deficit in interoceptive accuracy and differences in interoceptive sensibility in individuals with schizophrenia. For the first time, our study revealed intact interoceptive awareness in individuals with schizophrenia. Against our expectations, we found no link between schizotypy and interoceptive functioning in Experiment 2. Our novel findings bear important clinical implications as insight into one’s interoceptive limitations (i.e., intact interoceptive awareness) might promote treatment seeking behavior in schizophrenia. The lack of association between interoceptive ability and schizotypy in non-help-seeking youths suggests that changes in interoception may only arise with the onset of psychosis.


Science ◽  
2021 ◽  
Vol 372 (6543) ◽  
pp. eabe9681
Author(s):  
Mehran Ahmadlou ◽  
Janou H. W. Houba ◽  
Jacqueline F. M. van Vierbergen ◽  
Maria Giannouli ◽  
Geoffrey-Alexander Gimenez ◽  
...  

Exploring the physical and social environment is essential for understanding the surrounding world. We do not know how novelty-seeking motivation initiates the complex sequence of actions that make up investigatory behavior. We found in mice that inhibitory neurons in the medial zona incerta (ZIm), a subthalamic brain region, are essential for the decision to investigate an object or a conspecific. These neurons receive excitatory input from the prelimbic cortex to signal the initiation of exploration. This signal is modulated in the ZIm by the level of investigatory motivation. Increased activity in the ZIm instigates deep investigative action by inhibiting the periaqueductal gray region. A subpopulation of inhibitory ZIm neurons expressing tachykinin 1 (TAC1) modulates the investigatory behavior.


2001 ◽  
Vol 81 (2) ◽  
pp. 253-261 ◽  
Author(s):  
D. J. Gibb ◽  
S. M. S. Moustafa ◽  
R. D. Wiedmeier ◽  
T. A. McAllister

Feeding behavior and growth performance of cattle fed diets containing monensin or salinomycin were assessed in two trials. In trial 1, 36 Hereford × Angus steers (267.7 ± 4.3 kg) were individually fed (n = 12) wheat-based transition and finishing diets containing no ionophore (control, C), 26 mg monensin (M) or 13 mg salinomycin (S) per kg of dietary dry matter (DM). Cattle fed M consumed less than those fed C or S, and their intake was more stable during the transition to the finishing diet. Overall, steers fed M exhibited lower dry matter intake (DMI) (8.0 vs. 9.2 and 9.2 kg d–1) and rates of gain (1.21 vs. 1.62 and 1.56 kg d–1) than those fed C or S. Cattle fed S required fewer days (93.3) to reach the targeted finish (5 mm backfat) than those fed C or M (105.8 d). Monensin reduced slaughter weight and carcass weights, relative to controls (414.3 vs. 480.5 kg, and 231.2 vs. 245.8 kg, respectively). In trial 2, M (25 ppm) or S (13 ppm) were included in barley-based diets for 72 yearling steers placed in four pens equipped with radio frequency identification systems. Individual bunk attendance patterns were monitored during transition to a finishing diet, during 11 d of limit feeding the finishing diet twice daily (LF2/d), 13 d of limit feeding once daily (LF1/d), and 21 d of feeding once daily to ad libitum intake (AL1/d). Ionophore type did not affect (P > 0.10) DMI, rate of gain or efficiency of feed conversion. Bunk visits were more frequent (P < 0.05) with M than with S during transition and limit-feeding. With M, total daily attendance (TDA) at the bunk during LF1/d and AL1/d, was higher (P < 0.05) than with S, and variability in TDA was lower (P < 0.05) during LF1/d. In the present study, there was no performance advantage in providing S or M in wheat-based finishing diets. Monensin moderated feeding intensity, but this effect may have been strong enough to suppress intake and even reduce gain on the wheat-based diet. Key words: Ionophores, feeding behavior, feedlot cattle, salinomycin, monensin


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