Lectures+5+and+6+Postmortem+and+Imaging

Lectures+5+and+6+Postmortem+and+Imaging - How Can we Study...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 How Can we Study Human Aging? In vivo study is possible of: Anatomy (MRI Scanning) Neurochemistry (PET and MRI) Neurophysiology (PET and fMRI and EEG) Neuropsychology (cognitive processes) Postmortem Study of Anatomy (pathology) Chemistry (rapid postmortem interval) Postmortem Anatomical Methods Study Individuals during life At death, retrieve brain Gross (to naked eye) and microscopic examination Quantification of size and abnormal structures Relationships between measures obtained during life (memory function, etc) and postmortem measures
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Advantages and Disadvantages of Postmortem Measures Advantages High resolution Can measure many things Disadvantages You can only do it once (no longitudinal studies) Must have lifetime measurements in close temporal proximity (and you can’t predict death) May be contaminated by end of life changes Postmortem Anatomical Measurements - 3 Levels Whole Brain Size Volume/weight Volumes and cross sectional areas of structures Often performed on digitized images Histology Counting of Neurons, Glia Measurement of synaptic number, density Measurement of abnormalities - abnormal deposits, structures, proteins
Background image of page 2
3 Postmortem Normal Human Brain Postmortem Human Brain with Alzheimer’s Disease
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Measurement of Volumes of Structures is Possible on Postmortem Tissue Requires careful tissue processing Requires “rules” to define regions Painstaking, time consuming, not always reliable (ie, different people get different answers) Coronal Section-Normal
Background image of page 4
5 Coronal Section - Alzheimer’s Disease Example: Quantitation of Dendritic Length in Different Brodman Regions Step 1: Microscopy Step 2: Tracing Step3: Measurement
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Other Postmortem Measures Neurotransmitters Frozen tissue Measure transmitter, or the synthetic enzymes (Choline Acetyltransferase for acetylcholine) Proteins mRNA Disadvantages of all these techniques - postmortem stability - must obtain autopsy soon after death MRI Strong Magnetic Field (1.5-4 Tesla - roughly 80,000 X Earth’s magnetic field) - align protons Radio transmitter - impart RF energy to protons Radio Receiver - receive Gradient Coil
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/20/2010 for the course NEUROSCIEN Neuroscien taught by Professor Jagust during the Fall '09 term at École Normale Supérieure.

Page1 / 22

Lectures+5+and+6+Postmortem+and+Imaging - How Can we Study...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online