Tagged: blocker

The aggregating antics of (some) anaesthetics

This is one of those posts that I am reluctant to write because there is the very real possibility of it being taken out of context and causing someone to panic. But several readers have asked me to address a new piece of research that was published this week which has them concerned.

Anaesthetics are very useful agents in medicine, but they have long been known to have biological effects beyond simply numbing/sedating individuals. Some of those effects are beneficial, while others….mmm, not so beneficial. And the new research published this week leans towards the latter: Certain anaesthetics apparently induce mutant protein aggregation in neurons and cause stress responses in those brain cells.

In today’s post, we will discuss what anaesthetics are, how (we think) they work, and what the results of this new research actually mean.


William Morton’s first public demonstration. Source: Pinterest

On Friday 16th October 1846, history was made.

On that date, an American dentist named William T. G. Morton (1819-1868) made the first public demonstration of the use of inhaled ether as a surgical anaesthetic.

William Morton. Source: Wikipedia

At this demonstration Dr. John Collins Warren painlessly removed a tumor from the neck of a Mr. Edward Gilbert Abbott. After finishing the operation and Abbott had regained consciousness, Warren asked Abbott how he felt.

John Collins Warren. Source: General-anaesthesia

Abbott replied, “Feels as if my neck’s been scratched.”

Warren then turned to the medical audience and said:

“Gentlemen, this is no Humbug”

This was an obvious shot at an unsuccessful demonstration of nitrous oxide as a anaesthesia the year before (by Horace Wells in the same theatre), which ended with the audience shouting “Humbug!” after they heard the patient groaning with pain during the procedure.

The important thing to appreciate here is the magnitude of Morton’s achievement within in the history of medicine.

Before 16th October 1846, surgical procedures were not very pleasant affairs.

After 16th October 1846,… well, to be honest, they are still not very pleasant affairs, but at least the patient can skip most of the painful parts of an operation.

Interesting. But what does this have to do with Parkinson’s?

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O’mice an’ men – gang aft agley

This week a group of scientists have published an article which indicates differences between mice and human beings, calling into question the use of these mice in Parkinson’s disease research.

The results could explain way mice do not get Parkinson’s disease, and they may also partly explain why humans do.

In today’s post we will outline the new research, discuss the results, and look at whether Levodopa treatment may (or may not) be a problem.


The humble lab mouse. Source: PBS

Much of our understanding of modern biology is derived from the “lower organisms”.

From yeast to snails (there is a post coming shortly on a snail model of Parkinson’s disease – I kid you not) and from flies to mice, a great deal of what we know about basic biology comes from experimentation on these creatures. So much in fact that many of our current ideas about neurodegenerative diseases result from modelling those conditions in these creatures.

Now say what you like about the ethics and morality of this approach, these organisms have been useful until now. And I say ‘until now’ because an interesting research report was released this week which may call into question much of the knowledge we have from the modelling of Parkinson’s disease is these creatures.

You see, here’s the thing: Flies don’t naturally develop Parkinson’s disease.

Nor do mice. Or snails.

Or yeast for that matter.

So we are forcing a very un-natural state upon the biology of these creatures and then studying the response/effect. Which could be giving us strange results that don’t necessarily apply to human beings. And this may explain our long history of failed clinical trials.

We work with the best tools we have, but it those tools are flawed…

What did the new research report find?

This is the study:


Title: Dopamine oxidation mediates mitochondrial and lysosomal dysfunction in Parkinson’s disease
Authors: Burbulla LF, Song P, Mazzulli JR, Zampese E, Wong YC, Jeon S, Santos DP, Blanz J, Obermaier CD, Strojny C, Savas JN, Kiskinis E, Zhuang X, Krüger R, Surmeier DJ, Krainc D
Journal: Science, 07 Sept 2017 – Early online publication
PMID: 28882997

The researchers who conducted this study began by growing dopamine neurons – a type of cell badly affected by Parkinson’s disease – from induced pluripotent stem (IPS) cells.

What are induced pluripotent stem cells?

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