Neuroscience Methods Flashcards
Techniques for Visualizing the brain
- Histology
- Imaging the Living Brain
Histology Techniques
- Brainbow
- Golgi Stain
- c-fos
- Tracers (anterograde & retrograde)
Imaging the living brain techniques
- X-ray CT
- MRI
- PET
- DTI
Golgi Stain
Show us what neurons look like - cell body, dendrites, dendritic spines
Brainbow
different types of dyes - each neuron that is genetically different from another neuron will be colored differently
c-fos
which neurons are activated when I give this particular drug in this particular area (which neurons were c-fos positive)
Tracers
-Anterograde: injected in cell body area - tracing outlines neurons from their cell bodies to their terminals
-Retrograde: injected in terminals - tracing outlines neurons from their terminals to their cell bodies
X-ray CT
-(CT = computerized Tomography)
-Structural differences
MRI
-(Magnetic Resonance Imaging)
-Structural or functional
-More refined than CT scans
-Gray matter positioning
Function MRI
Measure increased activity (BOLD)
-Blood Oxygen Level Deficiency
DTI
-(Diffusion Tensor Imaging)
-White matter positioning, fiber
PET
-(Positron Emission Tomography)
-Radioactive ligands injected, picks up radioactivity released in the brain when imaging it
-Changes in receptors
Measuring Brain Activity
-Ex Vivo Electrophysiology
-In Vivo Electrophysiology
-Electroencephalography (EEG)
-Ex Vivo Fast Scan Cyclic Voltammetry
-In Vivo Microdialysis
-Magnetic Resonance Spectroscopy
Behavioral testing
- Wheel running
- Elevated plus maze
- Social interaction
- Morris water maze
- Rotarod
- Von Frey
Drug Administration Techniques
- Free & voluntary intake
- Operant conditioning
- Inhalation
Manipulating brain & behavior
- Optogenetics
- Transmagnetic Stimulation
- Deep Brain Stimulation
Ex Vivo Electrophysiology
-Use a recording pipette - break through membrane of neuron, suck the membrane up, tight vacuum seal
-Can measure action potentials, changes in voltages, etc.
-Single ionotropic channel recording
-measures neuronal activity in acutely prepared brain slices using either patch-clamp technology or extracellular recordings
-Brain slices permit recording of synaptic currents and membrane potentials, providing mechanistic insight into drug action.
In Vivo Electrophysiology
-measures neuronal activity in the brain as either local field potentials or single units
-Brain regions are targeted precisely, and the effect of test compounds can be assessed following either systemic delivery or by direct application using iontophoresis
Electroencephalography (EEG)
-a test that detects abnormalities in your brain waves, or in the electrical activity of your brain
-During the procedure, electrodes consisting of small metal discs with thin wires are pasted onto your scalp
-The electrodes detect tiny electrical charges that result from the activity of your brain cell
Ex Vivo Fast Scan Cyclic Voltammetry
Measure changes in dopamine, norepinephrine, serotonin release and uptake (clearance from the synapse)
In Vivo Microdialysis
Measure changes in neurotransmitter, amino acid & peptide release
Magnetic Resonance Spectroscopy
-Detect glutamate, choline, creatine, lactate and lipids, N-acetyl aspartate, Myo-inositol
-non-invasive analytical technique used to study changes in brain tumors, strokes, seizure disorders, Alzheimer’s disease, depression and other diseases
-analyze chemical composition of tissues
-analyze neurotransmitters
Wheel Running
-Measure locomotive activity in rats and mice
-Exercise measure
Elevated Plus Maze
-Measures anxiety-like behavior
-2 open arms and 2 closed arms
Social Interaction
-cage Mate vs non-cage mate on different sides of the cage
-See who a rat will interact with
-see where the rat spends most of its time
Morris Water Maze
-Test of memory
-Tub of water with a platform
-Rodents don’t like to be in water, so they will swim until they find the platform
-Test to see how long it takes the rat to find the platform and if they remember where it is
Rotarod
-Can rats stay on the rod while it’s rotating
-Performance test
Von Frey
-Mesh or barred floor
-Pain test - not a painful test, tests mechanical allodynia
-Use hairs of different thickness
-Assesses pain response
Free & Voluntary Intake
put both water bottles and ethanol bottles in the cage - allow rat to choose
Operant Conditioning
-Intravenous self-administration or Oral
-Showing the rat that there is a lever present, and if you press that lever at the right time (when the light turns on), you will get access to the drug
Inhalation
Place the animal in inhalation chambers and vaporize the drug → vapor floods the chamber and the rat/mouse will breathe it in
Optogenetics
-a technique in which genes for light-sensitive proteins are introduced into specific types of brain cells in order to monitor & control their activity precisely using light signals
-allows researchers to control how nerve cells communicate
-Uses light stimulation & genetic modification
-All of these studies are used by specific viruses that are not detrimental to health, they will just insert certain proteins
-Channelrhodopsin: cation (sodium) channel, gets activated by blue light - 473nM (Optical excitation of neurons) –> used to depolarize neurons, increase neuronal activity
-Halorhodopsin: anion (chloride) channel, gets activated by yellow light - 589nM (Optical inhibition of neurons)
–> used to hyperpolarize neurons, decrease neuronal activity
Transmagnetic Stimulation
-Send magnetic stimulation through the skull to activate certain types of neurons (non-invasive)
-Use for depression, anxiety, addiction, etc.
-Cannot be used for deep brain structures
Deep Brain Stimulation
-Neurosurgeons place a probe deep in the brain to activate a circuit with positive stimulation
-More invasive
-Used to treat Parkinson’s
