TY - JOUR T1 - Highlights from this issue JF - Archives of Disease in Childhood - Fetal and Neonatal Edition JO - Arch Dis Child Fetal Neonatal Ed SP - F1 LP - F1 DO - 10.1136/archdischild-2014-307910 VL - 100 IS - 1 AU - Martin Ward Platt Y1 - 2015/01/01 UR - http://fn.bmj.com/content/100/1/F1.abstract N2 - Biological rhythms are fundamental aspects of biology and physiology: cellular clocks are probably as old as life itself, and the more complex the organism, the more complex and interrelated these clocks become. Biological rhythms have been well studied in non-humans and human adults. But fetuses have rhythmicity too, and there has been very little information about how human fetal rhythms transform into ‘adult type’ rhythms during infancy. Filling this gap, Joseph and colleagues have described the ontogeny of rhythmicity in infancy, and have shown how different ‘adult’ rhythms do not all happen at once, but appear in sequence: first cortisol, then melatonin and sleep rhythms, then ‘adult’ type circadian temperature cycles, and finally rhythmicity of a histone gene which is related to intracellular clock functions. This is not to say that there are not other rhythms that may in future be elucidated, nor do we yet know the underlying mechanism for the development of cortisol rhythmicity. But it is nevertheless a huge step forward in our understanding of infant physiology. See page F50 One of the key characteristics of rhythms that are close in frequency is their ability to … ER -