research methods

CT scan

takes “photograph” of brain, inject iodine into blood to see structures, see splice of brain

MRI

good resolution, produces 3D images of brain’s structure by radio waves hitting hydrogen atoms in magnetic field

fMRI

provide flow of oxygenated blood around brain to track neural activity

• info abt structural, functional & temporal resolution

PET scan

inject brain w/ radioactive compound, 2 DG: modifieid radioactie sugar that cells can’t break down, later replaced by L-Dopa

• expensive to function, laborious

EEG

use macroelectrodes (metal discs) on top of head to measure electrical activity

• associated w/ diff states of consciousness, sleep & neural degeneration

radiofrequecy lesions

burning of tissue, current passed thru metal wire to cause insulation

exitotoxic lesions

injection of glutamate receptor agonist that causes cell to spike until it undergoes apoptosis

sham lesion

used as control, placebo procedure that duplicates all steps of brain lesion except for step that causes actual damage

reversible lesion & examples

inject drugs that temporarily inhibit neuronal spiking

• ex: voltage gated Na+ channel blockers

• GABA receptor agonists

4 methods for studying brain in animals

experimental ablation (lesion studies), chemical stimulation, electrical stimulation, optogenetics

chemical stimulation

implant metal straw to infuse drugs thru

electrical stimulation

implant metal wire to induce electrical stimulation to neurons

• microelectrodes help record electrical activity of individual neurons

optogenetics

work on light-sensitive neurons (opsins), using light to depolarize/hyperpolarize neurons