The Development of Circadian Rhythms in Human Infants

� What if any are the factors which have an effect on the development of core
body temperature maturation, secretion of cortisol and melatonin and the
development of infant sleep?
� Is there any suggestion of ordering/timing of physiological events in human
infants in the first postnatal months?
� Can the genetic output of the clock be detected and measured in human infants
from buccal swabs and are there any longitudinal changes with age?
All of the work was conducted within the home setting. No attempts were made to
control any external environmental factors (lighting, noise, care settings) and infants
were studied while families followed their normal schedule of care with no changes in
their routine (sleep time, feeding, and activity). The parents (predominantly mothers)
acted as the main research assistants.
First, the discussion will examine how well the above stated questions were answered.
The development of a pattern of core body temperature maturation will be discussed.
This will be followed by a discussion of the description of the patterns of secretion of
cortisol and melatonin and how infant sleep changes with age. Thirdly an examination
of the pilot data for the peripheral cycling genes from infant buccal swabs and the
significance of that data will follow. Next an exploratory description of the
relationship between the data collected for different physiological (temperature and
hormonal) behavioural (infant sleep) and genetic (peripheral cycling gene) parameters
will be discussed.
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