Chicken hatchlings prefer ambient temperatures lower than their thermoneutral zone

Toro-Velasquez, Paula Andrea; Bícego, Kênia C.; Mortola, Jacopo P.

doi:10.1016/j.cbpa.2014.06.008

Cited by 9 publications

(4 citation statements)

References 22 publications

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“…3) while the selected Tas by Nx chicks was between 24 and 27°C ( Fig.4). Such observation is similar to that found in leghorn hatchlings, which prefer Ta below their TNZ (Toro-Velasquez et al, 2014), but this subject needs further investigation to be confirmed in older chicks.…”

Section: Energy Metabolism and Thermoregulation Of 10-day Old Chicks supporting

confidence: 87%

“…As expected, both groups selected lower Tas during acute hypoxia exposure, which is considered a response that favors Tb reduction during low oxygen condition (Gordon and Fogelson, 1991;Gordon, 1997). One may argue that the results of thermal preference were influenced by keeping two animals at the same lane of the thermal gradient, but this may not be the case because, at least in hen hatchlings, being alone or in pairs makes no difference in the thermal preference (Toro-Velasquez et al, 2014).…”

Section: Energy Metabolism and Thermoregulation Of 10-day Old Chicks mentioning

confidence: 53%

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Hypoxia during embryonic development increases energy metabolism in normoxic juvenile chicks

Amaral-Silva

Scarpellini

Toro-Velasquez

et al. 2017

Comparative Biochemistry and Physiology Part A: Molecular &

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Environmental changes during perinatal development can affect the postnatal life. In this sense, chicken embryos that experience low levels of O over a specific phase of incubation can have their tissue growth reduced and the ventilatory response to hypoxia blunted, at least until hatching. Additionally, exposure to low level of O after birth reduces the thermogenesis as well. In the present study, we tested the hypothesis that hypoxia over the third week of incubation affects the thermoregulation of juvenile chicks at an age when thermogenesis is already expected to be well-developed. To this end, we measured body temperature (Tb) and oxygen consumption (V̇0) under acute hypoxia or different ambient temperatures (Ta) of 1 and 10day-old chicks that have been exposed to 21% O2 for entire incubation (Nx) or to 15% O in the last week of incubation (Hx). We also assessed the thermal preference under normoxia or acute hypoxia of the older chicks from both incubation groups in a thermocline. Hypoxia over incubation reduced growth but did not affect the cold-induced thermogenesis in hatchlings. Regarding the juvenile Hx, present data indicate a catch up growth with higher resting V̇0, a thermal preference for warmer Tas and a possible higher thermal conductance. In conclusion, our results show that hypoxia over the third week of incubation can affect the thermoregulation at least until 10days after hatch in chickens.

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Section: Energy Metabolism and Thermoregulation Of 10-day Old Chicks supporting

confidence: 87%

Section: Energy Metabolism and Thermoregulation Of 10-day Old Chicks mentioning

confidence: 53%

Hypoxia during embryonic development increases energy metabolism in normoxic juvenile chicks

Amaral-Silva

Scarpellini

Toro-Velasquez

et al. 2017

Comparative Biochemistry and Physiology Part A: Molecular &

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“…As a consequence, changes in thermoregulation are observed during the animal's development, as thermosensitivity changes with aging, i.e., a T a that is considered neutral in early life, is normally supraneutral for adults. In this way, precocial birds are excellent models for studying the development of thermogenesis since endothermy is already present as soon as they hatch and the shift in thermosensitivity can be observed by activation of heat loss/heat conservation thermoeffectors in early life (Mathiu et al, 1991;Khandoker et al, 2004;Mortola and Maskrey, 2011;Toro-Velasquez et al, 2014;Cristina-Silva et al, 2021;Amaral-Silva et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

Cutaneous TRPV4 Channels Activate Warmth-Defense Responses in Young and Adult Birds

et al. 2022

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Transient receptor potential vanilloid 4 (TRPV4) channels are sensitive to warm ambient temperatures (Tas), triggering heat loss responses in adult rats in a Tas range of ∼26–30°C. In birds, however, the thermoregulatory role of TRPV4 has never been shown. Here, we hypothesized that stimulation of TRPV4 induces thermolytic responses for body temperature (Tb) maintenance in birds, and that this function is already present in early life, when the Ta range for TRPV4 activation does not represent a warm condition for these animals. We first demonstrated the presence of TRPV4 in the dorsal and ventral skin of chickens (Gallus gallus domesticus) by immunohistochemistry. Then, we evaluated the effects of the TRPV4 agonist, RN1747, and the TRPV4 antagonists, HC067047 and GSK2193874, on Tb and thermoeffectors at different Tas in 5-day-old chicks and 60-day-old adult chickens. For the chicks, RN1747 transiently reduced Tb both in thermoneutrality (31°C) and in a cold Ta for this phase (26°C), which relied on huddling behavior inhibition. The TRPV4 antagonists alone did not affect Tb or thermoeffectors but blocked the Tb decrease and huddling inhibition promoted by RN1747. For the adults, TRPV4 antagonism increased Tb when animals were exposed to 28°C (suprathermoneutral condition for adults), but not to 19°C. In contrast, RN1747 decreased Tb by reducing metabolic rate and activating thermal tachypnea at 19°C, a Ta below the activation range of TRPV4. Our results indicate that peripheral TRPV4 receptors are functional in early life, but may be inhibited at that time when the range of activation (∼26–30°C) represents cold Ta for chicks, and become physiologically relevant for Tb maintenance when the activation Ta range for TRPV4 becomes suprathermoneutral for adult chickens.

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“…Precocious birds, including Galliformes, become endothermic at the end of incubation (Dzialowski et al, 2007;Nichelmann and Tzschentke, 2002;Price et al, 2018;Seebacher, 2009;Seebacher et al, 2006;Szdzuy et al, 2008). They hatch covered in plumage, possessing a well-developed nervous system and muscular and locomotor function, and can elicit thermogenic responses to cold (Khandoker et al, 2004;Mathiu et al, 1991;Mortola, 2009;Mortola and Maskrey, 2011;Toro-Velasquez et al, 2014) and thermal tachypnea when exposed to heat (Bícego and Mortola, 2017). As precocious birds, chicks are excellent models for studying thermal physiology at this early stage of life and, thus, were used in the present study.…”

Section: Introductionmentioning

confidence: 99%

A thermoregulatory role for the medullary raphe in birds

Cristina-Silva

Gargaglioni

Bícego

2021

Journal of Experimental Biology

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The brainstem region medullary raphe modulates non-shivering and shivering thermogenesis and cutaneous vasomotion in rodents. Whether the same scenario occurs in the other endothermic group, i.e. birds, is still unknown. Therefore, we hypothesised that the medullary raphe modulates heat gain and loss thermoeffectors in birds. We investigated the effect of glutamatergic and GABAergic inhibitions in this specific region on body temperature (Tb), oxygen consumption (thermogenesis), ventilation (O2 supply in cold, thermal tachypnea in heat) and heat loss index (cutaneous vasomotion) in one-week-old chicken exposed to neutral (31°C), cold (26°C) and heat (36°C) conditions. Intra-medullary raphe antagonism of NMDA glutamate (AP5; 0.5, 5 mM) and GABAA (bicuculline; 0.05, 0.5 mM) receptors reduced Tb of chicks at 31°C and 26oC, due mainly to an O2 consumption decrease. AP5 transiently increased breathing frequency during cold exposure. At 31°C, heat loss index was higher in the bicuculline and AP5 groups (higher doses) than vehicle at the beginning of the Tb reduction. No treatment affected any variable tested at 36oC. The results suggest that glutamatergic and GABAergic excitatory influences on the medullary raphe of chicks modulate thermogenesis and glutamatergic stimulation prevents tachypnea, without having any role in warmth-defence responses. A double excitation influence on the medullary raphe may provide a protective neural mechanism for supporting thermogenesis during early life, when energy expenditure to support growth and homeothermy is high. This novel demonstration of a thermoregulatory role for the raphe in birds suggests a convergent brainstem neurochemical regulation of body temperature in endotherms.

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Chicken hatchlings prefer ambient temperatures lower than their thermoneutral zone

Cited by 9 publications

References 22 publications

Hypoxia during embryonic development increases energy metabolism in normoxic juvenile chicks

Hypoxia during embryonic development increases energy metabolism in normoxic juvenile chicks

Cutaneous TRPV4 Channels Activate Warmth-Defense Responses in Young and Adult Birds

A thermoregulatory role for the medullary raphe in birds

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