The Pharmaceutical Journal
Vol 276 No 7383 p54
14 January 2006

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Ignore the circadian clock at your peril more
Structural abnormalities found in the brains of habitual liars more
Simple tastes and simple needs are the secrets of a contented life more

Ignore the circadian clock at your peril

In the 10 November 2005 issue of Nature a physiologist at Yale School of Medicine has commented on the complex factors controlling the circadian rhythm that affects us all.

From algae to human beings, living things have built-in clocks that are synchronised to the earth’s 24-hour rotation. When deprived of environmental clues — for example, when kept in constant darkness — these clocks maintain rhythms of about 24 hours but gradually drift out of synchrony with the earth’s rotation.

In animals, the clocks that control rest and activity depend on groups of neurons sited in the central nervous system. An important question is how oscillations of the cellular clocks within the organism are co-ordinated.

Studies of the fruit fly, Drosophila, have revealed two anatomically distinct groups of neurons that independently control morning and evening peaks of activity. In rodents a corresponding effect has been found to be produced by two distinct subpopulations of brain neurons whose firing rhythms are out of phase. When fruit flies are synchronised to light-dark cycles and then released into constant darkness, morning and evening peaks still persist, but run free and gradually drift out of phase with the earth’s rotation.

An investigation has been carried out into whether the morning or evening oscillator predominates or whether the two interact to establish a constant phase relationship. It seems that the morning peak controls the evening one, possibly by maintaining an hour-by-hour influence. An alternative explanation is that the evening peak is free-running, maintaining its own faster intrinsic period but being reset once a day by the morning surge.

It is possible that the mechanism involves a neuropeptide that has been given the name pigment-dispensing-factor and is expressed by morning-peak cells. In the absence of this factor, the evening peak is advanced by some two hours in fruit flies.

Whether oscillators in the human brain communicate in a similar fashion is unknown. Obviously, sleeping and waking and the functions they involve are highly important factors in determining a healthy or a hazardous lifestyle. To ignore them is asking for trouble, and our present ideas of a busy life expose us to lurking dangers.

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Structural abnormalities found in the brains of habitual liars

In these complicated times we are so used to coming across deliberate lies or distorted statements from our politicians and others who arrogantly claim to be our leaders in the struggle for life and decency that we regard the phenomenon of fibbing rather superficially. However, a report in the British Journal of Psychiatry recently indicates that the problem lies far deeper.

Research in California has revealed that the brains of habitual liars show a structural abnormality that particularly affects the prefrontal cortex. Activity in the prefrontal cortex is known to increase when normal individuals tell deliberate lies, and the research was designed to assess whether habitual liars have abnormalities in the volume of prefrontal grey and white matter.

A study sample of 108 community volunteers from five voluntary employment agencies in Los Angeles included 12 with a history of lying, 21 normal controls with no antisocial personality disorder or lying habits, and 16 other controls with antisocial personality disorder but no history of lying. The criteria examined included manipulative behaviour and lying to obtain sickness benefit. Structural magnetic resonance imaging was used to determine prefrontal grey and white matter.

Compared with both groups of controls, liars showed a 22–26 per cent increase in white matter and 36–42 per cent reduction in the ratio of grey to white matter. Differences in age, ethnicity, IQ, head injury or substance abuse were not involved. The brain abnormality was attributable to lying rather than to general antisocial behaviour. It is interesting to note that children with autism show the opposite pattern of grey-white ratio and that they are less capable of lying.

One explanation may be that increased development of prefrontal white matter provides the individual with cognitive capacity to lie. Psychosocial research has indicated that while young children are not convincing liars, they become more adept by the age of 10.

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Simple tastes and simple needs are the secrets of a contented life

I remember that in my school days there was a popular song that proclaimed: “A contented mind is a purse well-lined.” Since then I have often wondered how someone in these hectic and hazardous times can possibly develop a contented mind, and I have dismissed any prospect of a purse well-lined, which does not tempt me so long as I can pay my way from day to day and week to week.

Contentment has been defined as that state of mind in which desires are limited by present enjoyment, so that the impact of such factors as greed, ambition, jealousy and fear becomes critical to health, and we can think about serious challenges like human rights and obligations.

In 1912, Joseph Conrad wrote: “All ambitions are lawful except those which climb upwards on the miseries of mankind.” This reflection leads us to think about what we mean when we talk glibly about “human rights”. Politicians fancy this expression and throw it about carelessly. Yet it is far from clear what it implies.

For some it means that I can do what I choose to myself and my neighbours, merely because I take some sort of pleasure in the act. Thus, I may blow cigarette smoke over people sitting near me, or venture intoxicated into society under the influence of alcohol or other drugs, because I claim my individual right to do so. I may drive a car or a boat so as to endanger my fellows, because it gives me pleasure and a sense of power. And if my pursuit of pleasure ruins my health, I am still entitled to the resources of the health services.

At some time or other, nevertheless, social rights have to give way to social obligations, which necessarily place some restrictions on one’s way of living. It is in striking a balance between these two demands that the secret of contentment lies.

To have simple tastes and simple needs makes contentment more achievable. To envy others their possessions and privileges makes it impossible and brings stress and all its problems. The magic word is “relax”.

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