Chemoreceptor control of heart rate and behaviour during diving in the tufted duck (Aythya fuligula).
- 1 March 1988
- journal article
- research article
- Published by Wiley in The Journal of Physiology
- Vol. 397 (1), 63-80
- https://doi.org/10.1113/jphysiol.1988.sp016988
Abstract
1. The role of chemoreceptors in the control of heart rate and behaviour during diving activity in the tufted duck was investigated in two ways. In a closed-looped experiment, ducks were exposed to ambient gas mixtures of varied composition during diving activity in an indoor tank. Characteristics of diving behaviour, heart rate and deep body temperature were monitored under hypoxic, hyperoxic and hypercapnic conditions and compared with those in air. Secondly, in an open-loop experiment the role of the carotid body (CB) chemoreceptors in the control of the responses to altered inspired gas composition and in the cardiac responses to extended and enclosed dives (Stephenson, Butler and Woakes, 1986) was investigated by chronic bilateral denervation of these receptors. 2. Heart rate during submersion was unaffected by inspired gas composition in control (data from intact and sham-operated ducks combined) and CB-denervated ducks, though diving behaviour was significantly modified in both groups of animals in response to altered inspired gas composition. Hypoxia and hypercapnia resulted in an increase inthe proportion of total diving time spent breathing at the surface. The main effect of hypoxia (9-10% O2) was to reduce dive duration in control ducks and this effect was almost completely abolished after CB denervation. Hypercapnia (5-6% CO2) reduced dive duration less markedly than hypoxia but it greatly increased the duration of the inter-dive inteval, effects which were were not significantly influenced by CB denervation. Hyperoxia (40-45% O2) had very little effect on either behaviour or heart rate during diving, although deep body temperature was significantly elevated in this gas mixture during diving activity. There was also a less marked, but nevertheless significant, apparent hyperthermia during diving activity in air on an indoor tank but not on an outdoor pond. Conversely, there was a significant apparent hypothermia during diving activity under hypoxic conditions. 3. The CB chemoreceptors were shown to play a role in cardiac control during diving under certain circumstances. The duration of pre-dive tachycardia was significantly increased in hypoxia and this increase was abolished after CB denervation. The rate of development of bradycardia during extended and enclosed dives was slowed following CB denervation, though the initiation of the responses in extended and enclosed dives and the eventual attainment of sub-resting heart rates in enclosed dives were not prevented, indicating that other, as yet unidenified, sensory inputs are involved in cardiac control under these conditions.This publication has 15 references indexed in Scilit:
- Role of central and peripheral chemoreceptors in diving responses of ducksAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 1982
- Foraging and Size Selection of Mussels by the Tufted Duck, Aythya fuligulaJournal of Animal Ecology, 1982
- Control of diving responses by carotid bodies and baroreceptors in ducksAmerican Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 1982
- Respiratory Physiology of Freely Diving Harbor Seals (Phoca vitulina)Physiological Zoology, 1980
- Hypoxia and Hypercapnia in the Respiratory Control of the Amazonian Manatee (Trichechus inunguis)Physiological Zoology, 1980
- Role of the arterial chemoreceptors in ventilatory and circulatory adjustments to hypoxia in awake Pekin ducksJournal of Comparative Physiology B, 1979
- Drugs Used for Avian Anesthesia: A ReviewPoultry Science, 1978
- The effect of hypercapnia on respiratory characteristics and diving behaviour of freely diving sealsRespiration Physiology, 1976
- The effect of progressive hypoxia on the respiratory and cardiovascular systems of the chickenThe Journal of Physiology, 1967
- Factors Determining the Circulatory Adjustments to Diving: I. Water immersionActa Physiologica Scandinavica, 1963