scholarly journals Oxytocin Signaling Regulates the Homeostatic Response to Cold Stress in Poikilothermic Vertebrates

2021 ◽  
Author(s):  
Adi Segev ◽  
Shany Krispin ◽  
Anouk M Olthof ◽  
Katery Hyatt ◽  
Liran Haller ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Cold Stress ◽  
Physiological Responses ◽  
Metabolic Physiology ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Evolutionarily Conserved ◽  
Neuroendocrine Responses ◽  
Altered Metabolism ◽  
The Brain ◽  
Homeostatic Response

When exposed to low temperature, homeothermic vertebrates maintain internal body temperature by activating thermogenesis and by altered metabolism, synchronized by neuroendocrine responses. Although such physiological responses also occur in poikilothermic vertebrates, the prevailing notion is that their reactions are passive. Here, we explored molecular hypothalamic and physiological responses to cold stress in the tropical poikilotherm Nile tilapia (Oreochromis niloticus). We show that cold exposed tilapia exhibit complex homeostatic responses, including increased hypothalamic oxytocin, plasma glucose and cortisol concomitant with reduced plasma lactate and metabolic rate. Pharmacological or genetic blockage of oxytocin signaling further affected metabolic rate in two cold-exposed poikilothermic models. This indicates that oxytocin, a known thermoregulator in homeotherms, actively regulates temperature-related homeostasis in poikilotherms. Overall, our findings show that the brain of poikilotherms actively responds to cold temperature by regulating metabolic physiology. Moreover, we identify oxytocin signaling as an adaptive and evolutionarily conserved metabolic regulator of temperature-related homeostasis.

Physiological responses and HSP70 mRNA expression of GIFT strain of Nile tilapia (Oreochromis niloticus) under cold stress

2013 ◽  
Vol 46 (3) ◽  
pp. 658-668 ◽  
Author(s):  
Gui-Cheng Shi ◽  
Xiao-Hui Dong ◽  
Gang Chen ◽  
Bei-Ping Tan ◽  
Qi-Hui Yang ◽  
...  
Keyword(s):  
Cold Stress ◽  
Mrna Expression ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Physiological Responses ◽  
Hsp70 Mrna ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Dissecting the localization of Tilapia tilapinevirus in the brain of the experimentally infected Nile tilapia, Oreochromis niloticus (L.)

2021 ◽  
Author(s):  
Nguyen Dinh‐Hung ◽  
Pattiya Sangpo ◽  
Thanapong Kruangkum ◽  
Pattanapon Kayansamruaj ◽  
Tilladit Rung‐ruangkijkrai ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus ◽  
The Brain

scholarly journals Morphological bases of phytoplankton energy management and physiological responses unveiled by 3D subcellular imaging

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Clarisse Uwizeye ◽  
Johan Decelle ◽  
Pierre-Henri Jouneau ◽  
Serena Flori ◽  
Benoit Gallet ◽  
...  
Keyword(s):  
Energy Management ◽  
Morphometric Analysis ◽  
Physiological Responses ◽  
High Light ◽  
Phytoplankton Diversity ◽  
Eukaryotic Phytoplankton ◽  
Evolutionarily Conserved ◽  
Photosynthetic Responses ◽  
Photosynthesis And Respiration ◽  
Subcellular Imaging

AbstractEukaryotic phytoplankton have a small global biomass but play major roles in primary production and climate. Despite improved understanding of phytoplankton diversity and evolution, we largely ignore the cellular bases of their environmental plasticity. By comparative 3D morphometric analysis across seven distant phytoplankton taxa, we observe constant volume occupancy by the main organelles and preserved volumetric ratios between plastids and mitochondria. We hypothesise that phytoplankton subcellular topology is modulated by energy-management constraints. Consistent with this, shifting the diatom Phaeodactylum from low to high light enhances photosynthesis and respiration, increases cell-volume occupancy by mitochondria and the plastid CO2-fixing pyrenoid, and boosts plastid-mitochondria contacts. Changes in organelle architectures and interactions also accompany Nannochloropsis acclimation to different trophic lifestyles, along with respiratory and photosynthetic responses. By revealing evolutionarily-conserved topologies of energy-managing organelles, and their role in phytoplankton acclimation, this work deciphers phytoplankton responses at subcellular scales.

scholarly journals Synaptic and epidermal accumulations of human acetylcholinesterase are encoded by alternative 3'-terminal exons.

1995 ◽  
Vol 15 (6) ◽  
pp. 2993-3002 ◽  
Author(s):  
S Seidman ◽  
M Sternfeld ◽  
R Ben Aziz-Aloya ◽  
R Timberg ◽  
D Kaufer-Nachum ◽  
...  
Keyword(s):  
Neuromuscular Junctions ◽  
Gene Transcript ◽  
Dna Encoding ◽  
Tissue Specific ◽  
Evolutionarily Conserved ◽  
Low Salt ◽  
Catalytically Active ◽  
Specific Accumulation ◽  
The Brain ◽  
Muscle Ache

Tissue-specific heterogeneity among mammalian acetylcholinesterases (AChE) has been associated with 3' alternative splicing of the primary AChE gene transcript. We have previously demonstrated that human AChE DNA encoding the brain and muscle AChE form and bearing the 3' exon E6 (ACHE-E6) induces accumulation of catalytically active AChE in myotomes and neuromuscular junctions (NMJs) of 2- and 3-day-old Xenopus embryos. Here, we explore the possibility that the 3'-terminal exons of two alternative human AChE cDNA constructs include evolutionarily conserved tissue-recognizable elements. To this end, DNAs encoding alternative human AChE mRNAs were microinjected into cleaving embryos of Xenopus laevis. In contrast to the myotomal expression demonstrated by ACHE-E6, DNA carrying intron 14 and alternative exon E5 (ACHE-I4/E5) promoted punctuated staining of epidermal cells and secretion of AChE into the external medium. Moreover, ACHE-E6-injected embryos displayed enhanced NMJ development, whereas ACHE-I4/E5-derived enzyme was conspicuously absent from muscles and NMJs and its expression in embryos had no apparent effect on NMJ development. In addition, cell-associated AChE from embryos injected with ACHE-I4/E5 DNA was biochemically distinct from that encoded by the muscle-expressible ACHE-E6, displaying higher electrophoretic mobility and greater solubility in low-salt buffer. These findings suggest that alternative 3'-terminal exons dictate tissue-specific accumulation and a particular biological role(s) of AChE, associate the 3' exon E6 with NMJ development, and indicate the existence of a putative secretory AChE form derived from the alternative I4/E5 AChE mRNA.

Abstract 010: The Role of Angiotensin AT 1A Receptors in Leptin-sensitive Cells in Resting Metabolic Rate Control

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Kristin E Claflin ◽  
Justin L Grobe
Keyword(s):  
Metabolic Rate ◽  
Rate Control ◽  
Leptin Receptor ◽  
Resting Metabolic Rate ◽  
Critical Role ◽  
Renin Angiotensin System ◽  
Chow Diet ◽  
Brown Adipose ◽  
Diet Induced Thermogenesis ◽  
The Brain

The brain renin-angiotensin system (RAS) and leptin contribute to the control of resting metabolic rate (RMR) and their receptors are co-expressed in areas of the brain critical for metabolic control; thus angiotensin and leptin may interact within the brain to regulate RMR and obesity. Inhibition of the brain RAS attenuates sympathetic nerve activity (SNA) responses to leptin, leading us to hypothesize that the brain RAS mediates the RMR effects of leptin. Mice lacking angiotensin AT 1A receptors in leptin receptor-expressing cells (ObRb-Cre x AT 1A flox/flox ; “KO”) exhibited normal body weight (15 weeks of age: control n=28, 26.0 ± 0.7, vs KO n=35, 25.8 ± 0.6 g), food intake (control n=12, 3.1 ± 0.15, vs KO n=15, 3.4 ± 0.14 g) and RMR (control n=13, 0.15 ± 0.004, vs KO n=15, 0.16 ± 0.006 kcal/hr) on standard chow diet. Brown adipose SNA responses to acute leptin injection, however, were completely attenuated in KO mice. When maintained on a 45% high fat diet (HFD), KO mice gained significantly more fat mass (control n=35, 5.6 ± 0.4, vs KO n=31, 7.4 ± 0.5 g, P<0.05) and body mass (control, 27.4 ± 0.6, vs KO, 29.6 ± 0.6 g, P<0.05) due to a loss of diet-induced thermogenesis (control n=22, 0.18 ± 0.008, vs. KO n=12, 0.16 ± 0.004 kcal/hr, P<0.05). KO mice exhibited attenuated hypothalamic proopiomelanocortin (POMC) gene expression and partially attenuated RMR responses to alpha-melanocyte stimulating hormone (αMSH; control n=3, 0.25 ± 0.01, vs KO n=7, 0.2 ± 0.01 kcal/hr, P<0.05) indicating that the interaction between leptin and AT 1A modulates both αMSH production and action. To localize the site of the brain RAS-leptin interaction, we developed novel multi-transgenic mouse models which expresses GFP via the AT 1A promoter (NZ44, from GenSat) and/or conditional activation of a tdTomato reporter (ROSA-stop flox -tdTomato) in cells expressing the leptin receptor (ObRb-Cre) or agouti-related peptide (AgRP-Cre). Immunohistochemical staining of adrenocorticotropin in brain tissue from NZ44 mice revealed no localization of AT 1A to POMC neurons; in contrast, AT 1A was strongly localized with AgRP promoter activity. Taken together, these data support a critical role for angiotensin AT 1A receptors on AgRP neurons in the arcuate nucleus in resting metabolic rate control.

scholarly journals Social instigation and repeated aggressive confrontations in male Swiss mice: analysis of plasma corticosterone, CRF and BDNF levels in limbic brain areas

2017 ◽  
Vol 39 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Paula Madeira Fortes ◽  
Lucas Albrechet-Souza ◽  
Mailton Vasconcelos ◽  
Bruna Maria Ascoli ◽  
Ana Paula Menegolla ◽  
...  
Keyword(s):  
Aggressive Behavior ◽  
Physiological Responses ◽  
Plasma Corticosterone ◽  
Corticotropin Releasing Factor ◽  
Brain Areas ◽  
Social Stressors ◽  
Swiss Mice ◽  
The Brain ◽  
Over Time ◽  
Resident Intruder

Abstract Introduction: Agonistic behaviors help to ensure survival, provide advantage in competition, and communicate social status. The resident-intruder paradigm, an animal model based on male intraspecific confrontations, can be an ethologically relevant tool to investigate the neurobiology of aggressive behavior. Objectives: To examine behavioral and neurobiological mechanisms of aggressive behavior in male Swiss mice exposed to repeated confrontations in the resident intruder paradigm. Methods: Behavioral analysis was performed in association with measurements of plasma corticosterone of mice repeatedly exposed to a potential rival nearby, but inaccessible (social instigation), or to 10 sessions of social instigation followed by direct aggressive encounters. Moreover, corticotropin-releasing factor (CRF) and brain-derived neurotrophic factor (BNDF) were measured in the brain of these animals. Control mice were exposed to neither social instigation nor aggressive confrontations. Results: Mice exposed to aggressive confrontations exhibited a similar pattern of species-typical aggressive and non-aggressive behaviors on the first and the last session. Moreover, in contrast to social instigation only, repeated aggressive confrontations promoted an increase in plasma corticosterone. After 10 aggressive confrontation sessions, mice presented a non-significant trend toward reducing hippocampal levels of CRF, which inversely correlated with plasma corticosterone levels. Conversely, repeated sessions of social instigation or aggressive confrontation did not alter BDNF concentrations at the prefrontal cortex and hippocampus. Conclusion: Exposure to repeated episodes of aggressive encounters did not promote habituation over time. Additionally, CRF seems to be involved in physiological responses to social stressors.

Gastrointestinal satiety signals II. Cholecystokinin

2004 ◽  
Vol 286 (2) ◽  
pp. G183-G188 ◽  
Author(s):  
Timothy H. Moran ◽  
Kimberly P. Kinzig
Keyword(s):  
Small Intestine ◽  
Physiological Responses ◽  
Meal Size ◽  
Digestive Process ◽  
Important Mediator ◽  
Gastrointestinal Peptides ◽  
The Brain ◽  
Gastrointestinal Activity

During a meal, ingested nutrients accumulate in the stomach, with a significant portion passing on to the small intestine. The gastrointestinal presence of ingested nutrients initiates a range of physiological responses that serve to facilitate the overall digestive process. Thus peptides and transmitters are released, and various neural elements are activated that coordinate gastrointestinal secretion and motility and can eventually lead to meal termination or satiety. Among the range of gastrointestinal peptides released by ingested nutrients is the brain/gut peptide CCK. CCK plays a variety of roles in coordinating gastrointestinal activity and has been demonstrated to be an important mediator for the control of meal size.

scholarly journals Reward and aversion encoding in the lateral habenula for innate and learned behaviours

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Sarah Mondoloni ◽  
Manuel Mameli ◽  
Mauro Congiu
Keyword(s):  
Animal Species ◽  
Brain Structures ◽  
Individual Member ◽  
Negative Events ◽  
Lateral Habenula ◽  
Sensory Stimuli ◽  
Aversive Events ◽  
Evolutionarily Conserved ◽  
The Brain ◽  
Made In

AbstractThroughout life, individuals experience a vast array of positive and aversive events that trigger adaptive behavioural responses. These events are often unpredicted and engage actions that are likely anchored on innate behavioural programs expressed by each individual member of virtually all animal species. In a second step, environmental cues, that are initially neutral, acquire value through the association with external sensory stimuli, and become instrumental to predict upcoming positive or negative events. This process ultimately prompts learned goal-directed actions allowing the pursuit of rewarding experience or the avoidance of a danger. Both innate and learned behavioural programs are evolutionarily conserved and fundamental for survival. Among the brain structures participating in the encoding of positive/negative stimuli and contributing to innate and learned behaviours is the epithalamic lateral habenula (LHb). The LHb provides top-down control of monoaminergic systems, responds to unexpected appetitive/aversive stimuli as well as external cues that predict the upcoming rewards or punishments. Accordingly, the LHb controls a number of behaviours that are innate (originating from unpredicted stimuli), and learned (stemming from predictive cues). In this review, we will discuss the progresses that rodent’s experimental work made in identifying how LHb activity governs these vital processes, and we will provide a view on how these findings integrate within a complex circuit connectivity.

scholarly journals Alzheimer's disease-associated TM2D genes regulate Notch signaling and neuronal function in Drosophila

2021 ◽  
Author(s):  
Jose L Salazar ◽  
Sheng-An Yang ◽  
Yong Qi Lin ◽  
David Li-Kroeger ◽  
Paul C Marcogliese ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gene Family ◽  
Notch Signaling ◽  
Rare Variants ◽  
Neuronal Function ◽  
Evolutionarily Conserved ◽  
Cleavage Step ◽  
The Brain ◽  
Entire Gene

TM2 domain containing (TM2D) proteins are conserved in metazoans and encoded by three separate genes in each species. Rare variants in TM2D3 are associated with Alzheimer's disease (AD) and its fly ortholog almondex is required for embryonic Notch signaling. However, the functions of this gene family remain elusive. We knocked-out all three TM2D genes (almondex, CG11103/amaretto, CG10795/biscotti) in Drosophila and found that they share the same maternal-effect neurogenic defect. Triple null animals are not phenotypically worse than single nulls, suggesting these genes function together. Overexpression of the most conserved region of the TM2D proteins acts as a potent inhibitor of Notch signaling at the γ-secretase cleavage step. Lastly, Almondex is detected in the brain and its loss causes shortened lifespan accompanied by progressive electrophysiological defects. The functional links between all three TM2D genes are likely to be evolutionarily conserved, suggesting that this entire gene family may be involved in AD.

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