Effects of Orexin A on Thermal Behaviour: Substantial Evidences for Thermoregulatory Role of Orexin A
- *Corresponding Author:
- Marcellino Monda
Department of Experimental Medicine
Section of Human Physiology
Second University of Naples
via S.M. di Costantinopoli
16, 80138 Naples, Italy
E-mail: [email protected]
Received Date: August 13, 2014; Accepted Date: October 28, 2014; Published Date: November 03, 2014
Citation: Viggiano E, Messina G, Viggiano A, Viggiano A, Luca VD, et al. (2014) Effects of Orexin A on Thermal Behaviour: Substantial Evidences for Thermoregulatory Role of Orexin A. J Bioanal Biomed 06:040-044. doi: 10.4172/1948-593X.1000108
Copyright: © 2014 Viggiano E, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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.