Monday, 19 November 2012

Santiago Ramon y Cajal


If I am going to talk about how beautiful neuroscience can be, I should probably mention, fairly early on, the most famous neuro-artist there is. 

Take a minute to compare the two images below. Both are of a type of cell called a Purkinje cell, which are found in the cerebellum (at the back of the brain), and are essential for normal movement. One was draw, hand drawn, using paper and ink, in 1899. And the other, no less miraculous, was imaged using all the most sophisticated techniques we have at our disposal these days, by creating mice that express each neuron in the nervous system as a distinct colour, and imaging the brain using confocal microscopy. These 'brainbow mice', are quite brilliant, and are a story for another day. Today I want to focus on the scientist who managed to draw the same structures, in perfect anatomical detail, 108 years before the brainbow mice existed. 

Purkinje cells (labelled 'A') from the cerebellum of a pigeon, drawn by Cajal in 1899. Instituto Santiago Ramon y Cajal, Madrid, Spain.
Purkinje cells from the cerebellum of a mouse, imaged by Tamily Weissman in 2007. From the Brainbow mouse, produced by Livet J, Weissman TA, Kang H, Draft RW, Lu J, Bennis RA, Sanes JR, Lichtman, JW. Nature (2007) 450:56–62. Image can be found here.

His name was Santiago Ramon y Cajal, which is fun to say, and he was born in a village in north-east Spain in 1852, the son of the village surgeon. According to history, Cajal wanted to be an artist, but his father insisted he went to medical school instead. So he continued with art, but with anatomy as his subject. He saved up to buy himself an old fashioned microscope to begin his studies (I mean, now it would obviously be old fashioned, but apparently this one was old even in 1877), and was enventually awarded a shiney new one for the work he did during a cholera epidemic. 

In 1887 he was shown some slides of tissue stained with a new technique developed by an Italian scientist called Camillo Golgi. Golgi's techinque involved impregnating tissue with silver, which stained individual cells black and showed them with much greater clarity that the methods that Cajal had previously been using. Cajal wrote in his autobiography that "all was sharp as a sketch with Chinese ink". He modified this technique, and used it to provide the foundation of modern neuroanatomy, drawing thousand of beautiful images showing the intricacies of the nervous system in several species. Based on his observations he also came up with the theory that our brains and spinal cords are made up of countless individual cells, none of which come into direct contact with each other. These cells were later named neurons.

In 1906 Cajal and Golgi were jointly awarded the Nobel Prize in Physiology and Medicine for "revealing the inner beauty of the nervous system", becoming the first scientists ever to share the prize. This was slightly awkward, because Golgi had an conflicting opinion of the nervous system, believing it to be made up of a single continuous mesh. Apparently, their Nobel lectures directly contradicted each other. With the development of more powerful microscopes it was eventually possible to actually see a gap between cells in the nervous system, and Cajal was proved correct.

Laura


Wednesday, 5 September 2012

Gapminder

Image from www.gapminder.org
We just went to a lecture by Hans Rosling, who is Professor of International Health here at Karolinska. It was fantastic. Professor Rosling promotes a macro-view of world health and global development, and aims to replace myths with facts using beautiful gapminder views of global statistics and a complete lack of nonsense (when asked how he had arrived at a particular threshold value he said he used the powerful calculation of drawing a line on his graph). Throughout the talk he urged us not simply to produce pdfs of research for publication behind the copyright wall, and used toilet rolls to demonstrate how the global population will change in the next century.

The Gapminder World Map shown here was produced using the latest data about the world, and compares all UN members and other countries and territories with more than 1 million people, by income and health. If you have time, go to http://www.gapminder.org/, it will eat into your day but it couldn't be more worthwhile.

Laura

Tuesday, 21 August 2012

Dorsal root ganglion

Another close-to-home image for today; this one was taken by Susanne, who sits right next to me these days, whilst she was doing her Diploma Thesis at the NMI Natural and Medical Science Institute at the University of Tuebingen (in Germany) three years ago.


Susanne's image shows a dorsal root ganglion from a chicken. You normally find dorsal root ganglia (or DRGs) just next to the spinal cord, and dorsal to it (towards the back. Like a dorsal fin! Anatomy aide-memoire!). The ganglia bit in the name means that it is a mass of neuron cell bodies. And it's the root of a spinal nerve: a whole bunch of neurons all leaving the spinal cord and traveling out to the periphery together. DRGs like this one here contain sensory neurons, the ones bringing information back to your brain. The neurons that take information out to your periphery (like the motor neurons in Friday's picture, which cause movement of skeletal muscles) leave via the other side of the spinal cord.

The green staining is showing neurons, growing and projecting outwards from the DRG. The blue staining is showing the nuclei of all the cells (most of which aren't neurons, so we can only see their nuclei).

Once again, for scale, the bar represents 500μm (0.05cm, so 16 times bigger than the last image!).

If you like the images leave me a comment, it would be a delight to hear from you. Or subscribe by hitting the 'subscribe to' link at the bottom of the page. It will put a bookmark on your toolbar and put posts in it! Amazing! I have just discovered this nifty trick (I am sure it has been around for relative eons, but there you go). 

Laura


Friday, 17 August 2012

Neuromuscular junctions

Copyright seems more complicated than I could ever have imagined! And all I want to do is make neuroscience images more widely available.

So, to combat the copyright headache I will make my first image one that I know no-one else owns, since it is one of mine...


What you are looking at here is the connection between nerve (shown in green) and muscle (red) in the foot of a mouse. This connection is called a neuromuscular junction (for obvious reasons, when you break it down!), and they are responsible for every voluntary movement we make. Pretty useful little fellows. 

Normal healthy neuromuscular junctions look like the one on the right. The green nerve is spreading out across the bit of the muscle which is specialised to receive the signal about when to contract and produce movement. The one on the left is having a bit of a hard time. He's been severed from the rest of the nerve cell, and without connection to the cell body, way off in the spinal cord, the nerve has fragmented, and will soon be cleared away. That scale bar at the bottom represents 30μm. So 0.003cm. Otherwise known as pretty tiny.

I used to think they looked a bit like poppies. Now I just think they look like neuromuscular junctions. I suppose that's the effect of looking at them for four years, but I love them all the more for it. 

I'll hopefully bring you someone else's images soon! There are some unbelievable ones out there, you'll want them framed and on your wall...
Laura

Under construction...

Hello everyone,

I am currently in the process of setting up this blog, please bear with me whilst it looks entirely empty.

The idea is to post images from scientific articles, which are both beautiful on an aesthetic level, and awesome on a scientific level. And then to explain a little of the science behind them. The issue here is that all these images are copyright, and I can't work out whether they can be used on here with proper accreditation. Or if that is entirely illegal.

I'll keep trawling the web for answers, and find a way to bring you some images soon...