Sterling Johnson (UW) Brain Imaging in CR Monkeys
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Research: Brain aging and CR in rhesus monkeys

Brain starts to show signs of aging (amyloid plaques and ischemia)
in early adulthood in humans.

Human brain volume drops consistently w/ time after age 25.

CR brains (in rodents) not reduced in size, unlike other organs.
Same goes for testes (not reduced in size) which is nice  .

He is beginning studies in monkeys to test whether CR is good for
brain.

Using MRI technique to measure structure of brain

Looking at:
      Hippocampal volume
      Voxel-based statistical mapping to discover unexpected changes
          in brain structure sizes.

Using semi-automated MRI image processing to estimate structure size/volume.

Also going to do some functional MRI work, exact nature still TBD.

Studied normal (non-CR) monkeys so far. CR monkeys are next.

Hippocampal volume doesnt correlate with age in AL monkeys so far
- speculates they arent old enough to see atrophy effect. Peoples
hippocampus doesnt start to atrophy until around age 70.

Hippocampal volume normalized by cranial volume, to correct for 
variety in head size.

Brain mineral deposition (and accompanying amyloids) go up with age 
- particularly ferritin (iron) and calcium. Mineral deposition shows 
up differently in MRI. So MRI measures of mineral deposition may be 
useful for non-intrusively studying braining aging.

Voxel-based morphology - how much do you have to warp brain structure to 
fit standard brain atlas (canonical brain)? The degree and type of warping 
required to get match is what tells researcher how individuals brain 
differs from typical brain.

Now make brain atlas for normal, AL monkeys as baseline for comparison
with aging monkeys and CR monkeys.

Also doing PET scanning of monkeys after they've been acting normally in
cage for an hour to measure resting brain activity.  Measures glucose
uptake, and therefore brain activity in particular areas of the brain.
Making atlas of PET activity of normal, AL brains.

Also planning to do memory tests, and relating them to brain scan results
for various groups of monkeys.

In humans - cognitive difficulties (often associated with aging) and brain
atrophy are correlated with each other. He will try to test same thing in
monkeys, and see if CR attenuates these changes.

Submitted grant proposal to fund imaging component of the monkey studies.
Thinks chances are good theyll get money. Will be a couple years until
results will be available after funding received.

Wisconsin feeds their CR monkeys once daily.

Michael Rae asked - Since brain doesnt fully develop until early 20s,
what would be the effect of starting CR in teens?  Could be deleterious.