Brain washing

Our next exhibition – Brain Diaries: Modern Neuroscience in Action – opens on 10 March and in preparation we have indulged in a little bit of brain-washing… This article contains an image of a preserved human brain.

One of the first displays visitors will encounter is a ‘wall’ of 23 fluid-preserved mammal brains – from a Short-nosed Bandicoot to cow. The style of jar, with its black bitumen and paint backing, tells us that these were once used for display so it is exciting to put them in the public galleries again. Museum conservator, Jacqueline Chapman-Gray, runs us through the meticulous process she undertook to ensure these brains will look their best for their return to the limelight.

A number of the brains had become dehydrated over time as the level of fluid – alcohol – had dropped. These needed to go through a rehydration programme to ensure their long-term preservation. This is more complex than simply adding more fluid to the jar. Instead the alcohol level needs to be increased gradually to avoid damaging the tissues.

Others had started to detach from their glass mounts, or anatomy labels that marked each of the different areas or sections of the brain had come loose. These were carefully remounted using specialist conservation-grade materials and a steady hand! Three brains had become completely detached and were repaired using a polyester monofilament thread, otherwise known as fishing line.

For the smallest of the brains a normal sewing needle was enough to pass through the tissues but for the larger two either a flexible 10cm beading needle or large 25cm mattress needle was needed. The original threading points were reused wherever possible though in one case this proved to be too difficult, as the tissue was soft and susceptible to breaking. With precision and patience I was able to gently stitch them back into place on the backing plate so they look as good as new.

All of the jars were given a thorough clean to ensure that seals were tight fitting and that the contents were shown off to their best. They were then filled with fluid to 4/5ths from the rim and the brains gently placed back inside.

Lids were sealed with clear silicone and each jar was topped up with a syringe through a small hole in the lid that is there for this very purpose – once full, this hole is also sealed.

Lastly, after the seals had dried, for the final finishing flourish black paint was reapplied to the backs and tops of the jars to provide a contrasting backdrop.

Brain Diaries opens on Friday 10 March and runs until Monday 1 January 2018. Take a look at the website to find out more about the exhibition and accompanying programme of events at braindiaries.org