Research Topic:
- My research is concerned with the phenomenon of behavioural
thermoregulation. This phenomenon is being
studied via the use of two models: the branchiopod crustacean Daphnia carinata and
the genetically obese Zucker rat. Both these
models were chosen as each of tham has a novel aspect of their physiology which impacts
upon their ability to regulate body temperature behaviourally.
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- In common with many other species of daphniids, D. carinata
is capable of increasing rates of haemoglobin (Hb) synthesis when exposed to conditions of
hypoxia. It has been shown that cohorts of D.
carinata with different Hb contents respond differentially to hypoxia in a thermal
gradient: Hb-rich animals are capable of maintaining a higher Ta (Wiggins and
Frappell 2000). This work is currently being
built on by studying such differences in a naturally occurring population of D.
carinata and looking at differences between depths within a season and between
seasons.
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- A litter of Zucker rat pups consists of both lean (control)
and obese pups. A recent study (Maskrey,
Wiggins and Frappell 2000) has shown that there are differences in V·O2,
Tb and Ta between obese rats and cohorts of both age- and
weight-matched rats. This study is currently
being expanded to look at the effects of hypoxia on these and other parameters.
Behavioural thermoregulation – a hot topic!!
Publications
- Wiggins, P.R. and P.B. Frappell (2000). The influence of
Haemoglobin on Behavioural Thermoregulation and Oxygen Consumption in Daphnia carinata.
Physiological and Biochemical Zoology 73: 153-160.
- Maskrey, M., P.R. Wiggins and P.B. Frappell (2001). Behavioral
thermoregulation in obese and lean Zucker rats in a thermal gradient. Am. J. Physiol.
Regulatory, Integrative Comp. Physiol. 281: R1675-R1680.
- Frappell, P.B., Baudinette, R.V.,
MacFarlane, P.M., Wiggins, P.R. and Shimmin, G. (2002). Ventilation and metabolism in a
large semi-fossorial marsupial: the effect of graded hypoxia and hypercapnia Physiol.
Biochem. Zool. 75: 77-82.
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