PSY 250 Lecture Notes - Lecture 13: Positron Emission Tomography, Twin Study, Functional Magnetic Resonance Imaging
Garrett: Brain & Behavior, 3e
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1. Research*Techniques*
a. <%#1/1/=*and*imaging*neural*tissue*makes*it*possible*to*visualize*neurons,*glia*and*
connections*in*the*brain*
i. >,7=1(.%#1/<*randomly*stains*a*small*number*of*neurons*
ii. +9&71/(.%#1/.*identify*connections*by*staining*the*fatty*insulation*on*axons*and*
dendrites*
iii. ?1..7(.%#1/.*identify*neuron*cell*bodies*
iv. Anterograde*and*retrograde*stains*are*taken*up*at*the*synapse*and*transported*
to*the*cell*body*(fluorogold)*
v. Labeling*techniques*
(1) @6%,'#-1,='#$"9*reveals*both*neuronal*anatomy*and*function*
(a) Radioactive*sugar*is*injected,*which*is*taken*up*by*active*neurons*and*
therefore*are*seen*on*x<ray*devices*
(b) Radioactive*molecules*such*as*neurotransmitters*are*injected*and*bind*
to*receptors,*and*are*seen*on*scans*
(2) A;;6/,29%,2"&;1.%'9<*antibodies*are*labeled*with*markers*and*attach*to*
receptors*on*neurons*
(3) A/(.1%6("9B'1-1C#%1,/*labels*;&..&/=&'(4?@*with*radioactive*strands*of*
complementary*DNA*
b. Light*and*Electron*microscopy*
i. Light*microscopy*
(1) Good*for*enlarging*material*up*to*1000x;*requires*strong*light*and*optics*
(2) Includes*compound*microscope*and*stereomicroscopes*
11D 07&2%',/(;12',.2,$9(
(1) Uses*electrons*for*much*higher*magnification,*but*requires*a*computer*to*
visualize*specimens*
(a) <2#//1/=(&7&2%',/(;12',.2,$&*probes*a*specimen*with*an*electron*
beam,*causing*it*to*emit*electrons,*to*form*a*detailed*picture*of*the*
object*
(b) Confocal*laser*scanning*and*two<photon*microscopes*image*specific*
kinds*of*tissues*depending*on*the*fluorescent*dye*used,*and*can*be*used*
with*thicker*tissues*
c. Measuring*and*manipulating*brain*activity*
i. 07&2%',&/2&$"#7,='#$"9(E00>F(detects*electrical*activity*of*the*brain*through*
electrodes*placed*on*the*scalp*
(1) Temporal*resolution*is*high,*but*spatial*resolution*is*low;*EEG*is*most*useful*
for*detecting*changes*in*arousal*and*perception*
(2) 0G,H&-($,%&/%1#7.*rely*on*thousands*of*stimulus*presentations*to*cancel*out*
background*and*reveal*meaningful*changes*in*brain*activity*
ii. <%&'&,%#I12(1/.%'6;&/%.*and*techniques*
(1) A*stereotaxic*instrument*and*atlas*enable*precise*location*of*brain*areas*for*
stimulation*or*measurement*
(2) Electrodes*or*cannulae*are*placed*in*specific*areas*to*record*brain*activity*or*
to*inject*or*extract*substances*
Document Summary
Outline and key terms: research techniques, staining and imaging neural tissue makes it possible to visualize neurons, glia and connections in the brain, golgi stain randomly stains a small number of neurons, myelin stains identify connections by staining the fatty insulation on axons and dendrites, nissl stains identify neuron cell bodies, anterograde and retrograde stains are taken up at the synapse and transported to the cell body (fluorogold, labeling techniques (1) autoradiography reveals both neuronal anatomy and function (a) radioactive sugar is injected, which is taken up by active neurons and therefore are seen on x ray devices (b) radioactive molecules such as neurotransmitters are injected and bind to receptors, and are seen on scans (2) immunocytochemistry antibodies are labeled with markers and attach to receptors on neurons (3) in situ hybridization labels messenger rna with radioactive strands of complementary dna, light and electron microscopy.
