In the old days, when a patient started producing large quantities of urine, the doctor just stuck his finger in the urine and tasted it. If the urine tasted sweet, the patient had diabetes mellitus (= sweet flood). If the urine was not sweet, then the diagnosis was diabetes insipidus (= tasteless flood), and something was wrong with the kidneys or the brain.

Every day large quantities of blood pass through the kidney for cleaning purposes. During the cleaning process, the kidney recycles about 15 liters of fluid per day from the waste water. The kidney receives help with this from a brain hormone that inhibits the excretion of water, hence its name: “anti-diuretic hormone” (ADH). The same hormone is also known as “vasopressin” because it acts to raise the blood pressure. It is a small protein produced by the brain cells. These cells are located in the hypothalamus and transport the hormone to the rearmost part of the pituitary gland, where it enters the bloodstream.

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There was amazement all round when it was clinically proven that the effect of the most commonly used antidepressant was not significantly better than that of a placebo. But strangely enough, no one admires the effectiveness of the placebo. A placebo effect is any and all effects of a pill not caused by its specific chemical composition. For example, a red, yellow or orange pill is associated with a stimulating effect, while blue and green pills are thought to be calming.

A placebo can also have adverse effects. It can make a person nauseous or give them stomachache. People even get addicted to it, and develop withdrawal symptoms when the placebo treatment is terminated. There is thus sufficient reason to be interested in the effectiveness and the neurobiological mechanism of action of placebos. Lees verder »

The deterioration process proceeds slowly, step by step, in Alzheimer’s disease. Whatever one learned first is the last thing to disappear from memory.

Alzheimer’s disease follows a fixed route through the brain. When the typical signs of the disease, the ‘tangles’, develop in the entorhinal cortex and then a few appear in the hippocampus, those can be seen only under a microscope. No external symptoms are visible. But as the disease strongly takes hold in those areas of the brain, problems become evident in the short-term memory. One no longer remembers what happened just recently, but can recall minute details of a birthday party in primary school. When finally the Alzheimer’s disease reaches the other cerebral cortex regions, the patient becomes demented.

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Our average life expectancy has risen in the past century from 45 to almost 80 years, while, at the same time, we have to exert less and less physical effort to survive. The conclusion seems obvious: it pays to be lazy. However, nothing could be further from daily reality.

There are only a few things in this world that everyone seems to agree on, but people everywhere believe that it is bad to exercise little, and that we can only stay healthy by doing sports. The result is that, nowadays you cannot go for a peaceful walk in the woods without being overtaken by panting, sweating and clearly suffering joggers. Lees verder »