Abstract
Orexin A is a hypothalamic neuropeptide produced in the dorsal and lateral hypothalamus, and orexin-producing cell have widespread anatomical projections within the central nervous system. Orexin A is involved in multiple physiological functions, including eating behavior, thermoregulation, and sleep-regulation. The aim of this work was to study the thermal preference induced by orexin A. A thermal preference task with floor thermal gradient from 16°C to 25°C, divided into 10 equal segments, was designed to evaluate the thermal preferences in rats. Male rats (n=10, divided into two groups of five animals) received an intracerebroventricular injection of 1.5 nmol of orexin A or vehicle and were subsequently tested for thermal preference for 4 h. The results showed that the rats injected with orexin A had increased motor activity compared to the control group, particularly after the second hour of the test. Moreover the group treated with orexin A preferred hotter temperatures ranging from 24 to 25°C compared to the control group that preferred temperature of 22°C, which is near room temperature for rat housing (22 ± 1°C). No significant correlation was seen between thermal preference and time (hours). Since orexin A induces thermal preference, this study indicates that this neuropeptide plays a key role in the thermoregulation.
Highlights
Orexin A is a hypothalamic neuropeptide whose name was formerly introduced because of its putative role in eating behavior [1,2]
The total time spent moving by the orexin A group was higher in the first two hours compared to the control group (Figure 2A)
The present study demonstrates that the Intra Cerebro Ventricular (ICV) injection of orexin A causes an increase in locomotor activity and a modification of the thermal preference in rats
Summary
Orexin A is a hypothalamic neuropeptide whose name was formerly introduced because of its putative role in eating behavior [1,2]. Orexin A has an important role in thermoregulation; an Intra Cerebro Ventricular (ICV) injection of orexin A can increase body thermal This effect is present both in anesthetized rats and in animals without access to food, and suggests that thermogenesis induced by orexin is a consequence of food intake or motor activity [8,9]. Because thermoregulation depends on both vegetative and behavioral mechanisms, the aim of the present study was to evaluate the thermal behaviour induced by orexin A, namely, whether an ICV injection of orexin A can modify the thermal preference in rats To this end, a cage with a gradient thermal along the floor and a transparent wall was used to record, through a computerized visual system, the overall time spent moving or resting at each thermal ranging from 16 to 25°C
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
