Challenge to Traditional Theories About How the Brain Processes Actions

New research by Jason Gallivan and Randy Flanagan suggests that when deciding which of several possible actions to perform, the human brain plans multiple actions simultaneously prior to selecting one of them to execute.

The research is in Nature Communications. (full open access)

Research: “Action plan co-optimization reveals the parallel encoding of competing reach movements” by Jason P. Gallivan, Kathryn S. Barton, Craig S. Chapman, Daniel M. Wolpert and J. Randall Flanagan in Nature Communications doi:10.1038/ncomms8428

Image: Jason Gallivan (left) and Randy Flanagan are exploring how the human brain works. Image credit: Queensland University.

New Clues to the Evolution of the Primate Brain

The brain hidden inside the oldest known Old World monkey skull has been visualized for the first time. The creature’s tiny but remarkably wrinkled brain supports the idea that brain complexity can evolve before brain size in the primate family tree.

The research is in Nature Communications. (full open access)

Research: “Cerebral complexity preceded enlarged brain size and reduced olfactory bulbs in Old World monkeys” by Lauren A. Gonzales, Brenda R. Benefit, Monte L. McCrossin and Fred Spoor in Nature Communications doi:10.1093/chemse/bjv030

Image: The brain hidden inside the oldest known Old World monkey skull has been visualized for the first time. The ancient monkey, known as Victoriapithecus, first made headlines in 1997 when its 15 million-year-old skull was discovered on an island in Kenya’s Lake Victoria. Now, thanks to high-resolution X-ray imaging, researchers have peered inside its cranial cavity and created a three-dimensional computer model of what the animal’s brain likely looked like. The tiny but remarkably wrinkled brain supports the idea that brain complexity can evolve before brain size in the primate family tree. The creature’s fossilized skull is now part of the permanent collection of the National Museums of Kenya in Nairobi. Image credit: Fred Spoor of the Max Planck Institute for Evolutionary Anthropology.

This is a Gallyas stain. It’s a silver impregnation technique that is great for identifying fiber bundles. It’s similar to a much older staining technique called the Golgi stain, developed by Camillo Golgi. A side not about Golgi stains: They randomly stain complete neurons, but no one knows why some neurons are stained and others aren’t.

To do Galyas stains you’ll to do the following (protocol taken from this website):

1) Get some 0.5% acetic acid and 5% periodic acid

2) Make alkaline silver diode solution by dissolving 40g sodium hydroxide in water, then adding 100g potassium iodide. Add 35mls of 1% silver nitrate solution and stir really well. Then add 500mls of distilled water.

3) Make the following stock solutions. Simply dissolve each component consecutively.

STOCK SOLUTION I

  • Sodium carbonate (Anhydrous) 50g
  • Distilled water 1000ml

STOCK SOLUTION II

  • Ammonium nitrate 2g
  • Silver nitrate 2g
  • Tungstosilicic acid 10g
  • Distilled water 1000g

STOCK SOLUTION III

  • Ammonium nitrate 2g
  • Silver nitrate 2g
  • Tungstosilicic acid 10g
  • Formaldehyde (neat) 7.3ml
  • Distilled water 1000ml

Make a developer working solution by adding 3 volumes of stock solution II to 10 volumes of stock solution I. Stir and add 7 volumes of stock solution III. Stir and wait to clear.

4) Get 0.1% gold chloride, 1% sodium thiosulphate, 0.1% nuclear fast red (it’s just a stain), and 2.5% aluminium sulphate.

5) a 4-10 micron brain section

To actually stain do the following:

  1. Take sections to distilled water.
  2. Place in 5% periodic acid for 5 minutes.
  3. Wash in distilled water for 5 minutes twice.
  4. Place in alkaline silver iodide solution for 1 minute.
  5. Wash in 0.5% acetic acid for 10 minutes.
  6. Place in developer solution (prepare immediately before use) for 5-30 minutes.
  7. Wash in 0.5% acetic acid for 3 minutes.
  8. Wash in distilled water for 5 minutes.
  9. Place in 0.1% gold chloride for 5 minutes.
  10. Rinse in distilled water.
  11. Place in 1% sodium thiosulphate solution for 5 minutes.
  12. Wash in tap water.
  13. Counterstain in 0.1% nuclear fast red for 2 minutes.
  14. Wash in tap water.

Dehydrate the slides in alcohol and mount with some kind of synthetic resin and voila, you have some beautiful brain sections. This techniques stain soma as well. I’ve never personally done a silver stain, but I think Gallyas stains are some of the most appealing, even better than more modern immunofluorescent tags. 

First ever study records memory being encoded in individual neurons.

First ever study records memory being encoded in individual neurons. Thoughts health innovators?

In the first study of its kind researchers from UCLA and the University of Leicester found that neurons in a specific brain region play a key role in rapidly forming memories about every day events, a finding that may result in a better understanding of memory loss and new methods to fight it in Alzheimer’s and other neurological diseases.  Specifically, the new study examined neurons in the…

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