What Can Brain Research What Can Brain Research Tell Us About How We Tell Us About How We

Learn?Learn?

Mary BallMary Ball

Fall 2007Fall 2007

Early Brain StudiesEarly Brain Studies

Studies of People After Brain Surgery or Studies of People After Brain Surgery or Brain Injuries (e.g. Henry M.)Brain Injuries (e.g. Henry M.)

Post-Mortem Examination of Brains and Post-Mortem Examination of Brains and Brain Tissue (e.g. Alzheimer’s Disease)Brain Tissue (e.g. Alzheimer’s Disease)

Basic Brain StructureBasic Brain Structure

Composed of Neurons and Composed of Neurons and supporting cellssupporting cells

Myelinated axons appear white Myelinated axons appear white (hence called White Matter)(hence called White Matter)

Unmyelinated tissue appears grey Unmyelinated tissue appears grey (hence called Grey Matter)(hence called Grey Matter)

Neurons form “circuits” via Dendrites Neurons form “circuits” via Dendrites and Axonsand Axons

Basic Neuron StructureBasic Neuron Structure

Source: NIH Publication No.02-3440d Source: NIH Publication No.02-3440d

The Visible Human ProjectThe Visible Human Project

In 1994 and 1995, two cadavers In 1994 and 1995, two cadavers were frozen in gelatin.were frozen in gelatin.

Starting at the head end, the block of Starting at the head end, the block of frozen material was slowly ground frozen material was slowly ground down smooth and photos of the down smooth and photos of the surface were repeatedly taken.surface were repeatedly taken.

Photos were taken every mm for the Photos were taken every mm for the male and every 1/3 mm for the male and every 1/3 mm for the female.female.

Whisker Removal in Mice Leads Whisker Removal in Mice Leads to “Dendritic Spine Sprouting” to “Dendritic Spine Sprouting”

(2002)(2002)

In 1962, researchers reported evidence of limited In 1962, researchers reported evidence of limited

neurogenesis in rats following brain damage.neurogenesis in rats following brain damage.

In 1998, researchers reported In 1998, researchers reported neurogenesis in the adult human neurogenesis in the adult human

hippocampus.hippocampus.

Immunofluorescence for neurons (a), new Immunofluorescence for neurons (a), new cells (b), and glial cells (c) indicated the cells (b), and glial cells (c) indicated the new cells were neurons!new cells were neurons!

ToolTool How It WorksHow It Works

PET ScanPET Scan Detects active regions of the brain Detects active regions of the brain by tracing radioactive isotopes.by tracing radioactive isotopes.

fMRI ScanfMRI Scan Detects active regions of the brain Detects active regions of the brain by visualizing where oxygen is being by visualizing where oxygen is being used.used.

qEEGqEEG Detects active regions in the brain Detects active regions in the brain by electrical activity (brain waves).by electrical activity (brain waves).

MRI ScanMRI Scan Distinguishes gray matter, white Distinguishes gray matter, white matter, and ventricles.matter, and ventricles.

Voxel-Voxel-based based MorphometMorphometryry

Statistical procedure to measure Statistical procedure to measure average volume of a specific region average volume of a specific region of the brain.of the brain.

Brain Structures Differ between Musicians

and Non-Musicians (2003)

Gray matter increased in students Gray matter increased in students learning to juggle. (2004)learning to juggle. (2004)

Summary of What the Summary of What the Researchers Researchers Already KnewAlready Knew

The human hippocampi are important in The human hippocampi are important in long-term memory.long-term memory.

Neurogenesis is possible in the hippocampi Neurogenesis is possible in the hippocampi in adults.in adults.

Dentritic growth and spine sprouting have Dentritic growth and spine sprouting have been directly observed in mice adjusting to been directly observed in mice adjusting to change.change.

Voxel-Based Morphometry can be used to Voxel-Based Morphometry can be used to detect changes in gray matter volume over detect changes in gray matter volume over time and/or between groups.time and/or between groups.

Learning to juggle resulted in transient Learning to juggle resulted in transient increases in gray matter in a sample of increases in gray matter in a sample of young adults. young adults.