Control of breathing in ectotherm vertebrates: regulation of metabolic demand and gas transport

• Grant number: 05/00574-0
• Support Opportunities: Scholarships abroad - New Frontiers
• Start date: October 17, 2005
• End date: June 09, 2006
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Denis Otavio Vieira de Andrade
• Grantee: Denis Otavio Vieira de Andrade
• Host Investigator: William Keneth Milsom
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Institution abroad: University of British Columbia, Vancouver (UBC), Canada

Abstract

The metabolic rate of ectotherm vertebrates vary considerably as a function of environmental factors (temperature) and during the performance of different activities (e. g., digestion, exercise, dormancy). Such a large variation in metabolism requires concurrent adjustments of the cardio-respiratory function aimed to the maintenance of an adequate matching between metabolic demand and homeostasis. In the last few years, I have undertaken an extensive investigation on the proximal factors affecting the level of metabolic activity in reptiles and on the accompanying adjustments on the gas transport cascade. The results that I have achieved working under this approach, in terms of student formation and publications, can be verified at the accompanying CV. The controlling mechanisms and processes involved with the regulation of the metabolic response and with cardio-respiratory adjustments, however, have not been approached in my research program up till now. This is a major constraint to the fostering of following-up studies since, ultimately, the matching between metabolic demand and gas transport is ultimately a regulated process subjected to controlling mechanisms. The present proposal aims to remedy this major constraint by the realization of a posdoc at the Department of Zoology, University of British Columbia, Vancouver, Canada. At this institution, I will work in collaboration with the Prof. William K. Milsom, studying the regulatory mechanisms involved on the control of breathing in vertebrates. Prof. Milsom has long been one of the most authoritative researchers in comparative respiratory physiology, in general, and in the controlling of breathing, in particular. Moreover, Dr. Milsom has a successful history in developing collaborative projects with the lab I belong. Hopefully, by the end of the posdoc, new ideas and techniques will be implemented in my original institution and a substantial broadening of my research interest will be achieved. The rational for conducting the proposed experiments on ectotherm vertebrates is that 1) they are relatively easy to obtain and keep in captivity; 2) their morphology and extreme tolerance of environmental change (temperature, levels of O2, etc.) is conducive to employment of a myriad of experimental procedures allowing for the employment/learning/training of a great diversity of techniques; 3) fishes, amphibians, and reptiles exhibit a enormous diversity in respiratory strategies and include key organisms which allow us to address questions pertinent to the understanding of the water-air transition as a respiratory medium. Accordingly, the study of the control of breathing in these organisms is likely to improve our understanding of the evolutionary and adaptive aspects of respiration in general. (AU)