Monday 11 August 2014

A poisonous carrot?

I wrote this post right after reading Katherine Webb’s latest novel "A half-forgotten song".

Poison hemlock (Conium maculatum) is a very common weed distributed worldwide. And believe it or not, it belongs to the carrot family! 

You can find hemlock on river banks, or in woodland, pastures and waste ground.

It is believed that the juice of this plant was used to execute criminals in ancient Greece. It is also thought to have been the poison that killed Socrates in 399 BC.


Hemlock contains chemicals called alkaloids which are found in fruits, vegetables and flowers. Concentration of the alkaloids is what makes the plants more or less poisonous. The concentration depends on many factors like the variety and age of the plant, as well as the environmental conditions in which it grows. In 2013, up to eight alkaloids had been identified in poison hemlock, some of which had also been demonstrated to be toxic and to induce foetal malformations. 

Hemlock acts on the central nervous system causing symptoms like trembling, dilation of pupils, salivation, nausea and convulsions. Very bad poisoning can also cause coma and death due to respiratory failure. I was astonished to read that some of the cases of human poisoning happened when people mistook the hemlock leaves for parsley, or the roots for parsnips, or the seeds for anise.

But not everything is scary about hemlock. It was used in ancient medicine as a sedative, analgesic and antispasmodic. Even an article published in 1997 describes its use in homeopathy. Indians from the north of Mexico also use hemlock to stupefy fish and help their economy during low crop season.




Hopefully this post has sparked your interest in Katherine’s novel. 

When "Today is all you have"

I have just read the most amazing thriller! “Before I go to sleep” by S J Watson.

Christine Lucas, the main character, suffers from a rare kind of amnesia. She can remember a few things from her childhood and early years but nothing else. On top of that, she can’t form any new memories. Every day is a new day for her, the memories she manages to recall or things she does throughout the day, vanish completely once she goes to sleep.

This condition sounds horrible. The only type of amnesia I had heard of is the one where people can’t remember who they are, what happened to them, etc. I had never heard of people whose brains cannot generate new memories at all! This prompted a search in the literature to learn more about amnesia.



Amnesia is the deterioration of memory. It can be caused by physical damage to the brain, for example after hitting your head in an accident, or it can be linked to some psychiatric disorders. It can be due to medical conditions, like vitamin B1 deficiency, or to consumption of alcohol or drugs. It gets even more complicated when you look at the different types (or variants) there are. This review from The Lancet summarises all of them quite well. I was interested in the variants related to Christine Lucas’s case which are:

          Retrograde amnesia: when you cannot remember information that you are supposed to know.

         Anterograde amnesia: when you cannot form new memories.

Research in amnesia has increased. Imaging techniques such as MRI (Magnetic Resonance Imaging) are helping to understand what happens in the damaged brain, in particular which structures become deteriorated. This is not an easy task because there are many structures that are involved in different brain regions. Pharmacologically speaking, there is not yet a treatment that can be considered successful. Some drugs have been tried, but the evidence is still lacking. There are areas of research that still need to be explored, for example, the role that our genes and the environment may play.

On the brighter side, a group at the University of Bristol studied the formation of memories in the tiny fruit fly. They chose to use this insect as a model because the fruit fly brain is similar to the human brain in regards to neuronal function and responses. They found that the protein CASK was crucial in this process. CASK belongs to a family of proteins that modify and regulate the function of other proteins. In this particular case, CASK helps another protein called CaMKII, which is known as “the memory switch”, to function properly in memory formation.


Thanks to studies like this, scientists have now a better understanding of how memories are made. Certainly, this new information will help them to find possible therapies for memory loss. I am happy to know that there’s light at the end of the tunnel for those suffering from amnesia.


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