[tt] Neurons or Pollock? Scientists Create Technicolor 'Brainbow'

[Brian Atkins]

(8 photos at link)

http://www.wired.com/science/discoveries/multimedia/2007/10/gallery_fluorescentneurons

A Mouse Listening

Scientists at Harvard and MIT have genetically modified mouse neurons to fire 
"tracer" rounds that are helping researchers map the brain's intricate connections.

The scientists inserted a special gene into the mice that produces glowing 
proteins, extracted from coral and jellyfish. As the mouse thinks, the 
fluorescent proteins spread out along neural pathways. After the mice are 
euthanized, their nervous systems are cut into slices.

Left: This dense tangle of neurons is in the auditory portion of the brain stem. 
Mammals have very thick axons in the region, in part because the system needs to 
process sound quickly.

The Professor and the Microscope

Dr. Jeff Lichtman, a professor of molecular and cell biology at Harvard 
University, poses with his confocal microscope. The color microscope has red, 
cyan and yellow lasers that allow him to take fluorescent images of mouse neural 
activity contained in this gallery. He calls them "Brainbow" images.

A Neuron in the Brain Stem

Each neuron acts as a different shade of highlighter that traces signals through 
the mouse brain. The lines in the images indicate traffic between various 
neurons, like Internet maps that trace packets through different servers. Under 
a special microscope, cyan, yellow and red lasers cause each neuron to shine a 
different color, so researchers can tag individual neurons by their hue.

Left: One brain stem neuron (red) surrounded by the remnants of signals from 
other neurons (blue, yellow). The brain stem generally handles the lower level 
brain functions like breathing and heartbeat.

Masses of Neurons Coordinating Movement

Understanding neuronal connections could shed light on psychiatric disorders 
like schizophrenia that scientists believe arise from "wiring" problems.

"Our ultimate goal is to create automated systems that will take a sample of 
brain tissue as input and generate its 'circuit diagram,' a list of all its 
neurons and their synaptic connections, said Sebastian Seung, an MIT professor.

Left:The cerebellum is the central command for the mouse's movements. If a mouse 
could learn to ride a bike, these are the cells that would make it happen. The 
cells pictured are bringing information to the cerebellum, telling it what's 
going on with the muscles.

The Cabling From the Brain to the Body

These slender axons are the connecting wires between the brain and the motor 
neurons in the mouse body. They would send the mouse's muscles directions to 
move (or run).

The Brain's Little Helpers

Glial cells, like these astrocytes, take care of the hard-thinking neurons' 
physical needs like eating and protection. Astrocytes, specifically, play a 
major role in brain repair.

Colorful "Gray Matter"

These neurons sit in the cerebral cortex, often referred to as the gray matter 
for the area's color in non-living specimens. These cortical neurons are 
involved in higher-thought processes and perception of different senses.

A Snapshot of Memory

This image from the hippocampus shows smaller glial cells (the small ovals) 
among neurons (larger, with more filaments). The hippocampus is known to play a 
major role in memory formation.

-- 
Brian Atkins
Singularity Institute for Artificial Intelligence
http://www.singinst.org/