Study Guide: Neuroanatomical Techniques Flashcards
Nissl Stain developed by:
Franz Nissl
Nissl Stain is used to:
differentiate neurons and glial cells, study neuronal shapes and sizes
Nissl stain uses what kind of dye?
Basic aniline dyes (e.g. cresyl violot, toluidine blue, methylene blue)
The basic aniline dye used by Nissl stain binds to
negatively charged nucleic acids (RNA and DNA)
Nissl stain stains nuclei and Nissl bodies, the latter which is:
Rough ER with with ribosomes and nuclei
Nissl stain highlights:
neurons over glial cells due to higher RNA concentration (neurons have a much higher protein synthesis activity)
Nissl Stain: Application
Used for:
NEURONAL CYTOARCHITECTURE studies and examining
NEURONAL POPULATION CHANGES
Golgi stain was developed by:
Camille Golgi in the 1870s
Golgi stain mechanism:
- Fixation
- Impregnation
Describe the fixation mechanism (first step) of Golgi stains:
Tissue is treated with potassium dichromate to create reactive sites
Describe the impregnation mechanism (step #2) of Golgi stains:
Impregnation: silver nitrate (AgNO3) reacts with dichromate-treated tissue forming silver chromate microcrystals
Golgi stain: selective staining:
Only a subset of neurons are stained, allowing detailed visualisation of dendrites and axons
Golgi stain: Applications(2):
(1) Used extensively by Santiago Ramon y Cajal to develop the neuron doctrine
(2) Visualizing dendritic spines and neuronal morphology
Nissle stain: Target
Nissle bodies (rough Er)
Golgi stain: Target:
Entire neuron (soma, dendrites, axons)
Nissl Stain: Selectivity
Labels all neurons
Golgi Stain: Selectivity:
Labels only a subset of neurons
Nissl Stain Primary use:
Cytoarchitecture
Golgi Stain: Primary use:
Morphology of individual neurons
Nissle Stain Color:
Blue/purple
Golgi stain color:
Black
Immunocytochemistry (ICC) / Immunohistochemistry (IHC)
Uses antibodies to detect specific proteins (e.g. neurotransmitters, receptors)
Immunocytochemistry (ICC) / Immunohistochemistry (IHC): Applications (3) :
(1) Identifying neurons vs glia
(2) Mapping neurotransmitter distribution
(3) Studying pathological conditions (e.g. neurodegeneration, tumors)
Immunocytochemistry (ICC) / Immunohistochemistry (IHC): mechanism:
(1) Antibodies bind to target proteins (antigens)
(2) Markers used for visualizations
What are the two common types of markers used for visualization inImmunocytochemistry (ICC) / Immunohistochemistry (IHC): What are the two types of markers used for visualization:
(1) Fluorescent dyes –> fluorescence microscopy
(2) Enzymes (horseradish peroxidase) –> colored reaction under light microscopy
Advantages of immunocytochemistry/ immunohistochemistry (2) :
-High specificity and sensitivity
-Can be combined with confocal microscopy for 3D imaging
Limitations (2) of immunocytochemistry / immunohistochemistry:
(1) Requires well -validated antibodies
(2) Signal strength varies with antigen accessibility
In situ hybridization (ISH):
Uses complementary RNA probes to detect mRNA expression
Applications In situ hybridization (ISH) (2):
(1) Research: Gene expression mapping in neurons
(2) Clinical: Brain tumour diagnosis, schizophrenia research (identifying altered transcript localization)
In situ hybridization (ISH): procedure:
- Fixation
- Probe design
- Hybridization
- Washing
- Detection
In situ hybridization: Fixation
Preserves tissue structure
In situ hybridization: Probe design:
Complementary to target mRNA
In situ hybridization: Hybridization:
Probe binds to mRNA
In situ hybridizaiton: Washing:
Removes unbound probes
In situ hybridization: Detection:
Fluorescence, autoradiography, or enzyme reactions
In situ hybridizaiton: Advantages:
High-resolution gene expression mapping
In situ hybridization: limitations:
Time - intensive, requires careful probe design
What are two genetic techniques (2):
(1) Brainbow techniques
(2) Optogenics
Brainbow technique uses:
genetically encoded fluorescent proteins to label neurons in multiple colors
Brainbox technique: Applications (2):
(1) Single cell resolution mapping of neural circuits. Each cell is labelled with a unique color, so that neurites can be individually traced (e.g. you can find out where a specific axon goes in order to understand how the circuit is connected)
(2) DNA constructs with fluorescent proteins (GFP,CFP,YFP) are randomly recombined, producing unique neuron colors
Optogenics uses:
Light sensitive ion channels (e.g. channelrhodospins) to control neuronal activity with light
Optogenics applications(2):
(1) Mapping neuronal connectivity (e.g. whether a set of neurons in area A excites or inhibits a downstream neuronal poopulation in area B)
(2) Understanding behaviour- related neuronal activity
Viral based tracing:
Uses modified viruses to trace synaptic connections
Viral based tracing: common tracers:
(1) herpes simplex virus (Multi synaptic tracing)
(2) Rabies virus (retrograde transsynaptic tracing)
(3) Pseudorabies virus (PRV) (traces from axon terminals to soma)
Viral based tracing: Herpes simplex virus:
Multi synaptic tracing
Viral based tracing: rabies virus:
retrograde transsynaptic tracing
Viral based tracing: Pseudorabies virus (PRV) :
traces from axon terminals to soma
Viral based tracing: Applications (2):
(1) Mapping functional networks
(2) Studying long-range neural pathways
Dye based tracing:
uses axonal transport to trace connections
Dyes used in Dye based tracing:
Horseradish peroxidase (HRP)
Fluorogold
Dextrans
Transport types in Dye -Based tracing:
Anterograde: Soma -> axon terminals
Retrograde: Axon terminals -> Soma
Diffusion tensor imaging:
specialized MRI that maps white matter tracts
Diffusion Tensor Imaging (DTI): Mechanism:
Specialized MRI that maps white matter tracts
Diffusion tensor imaging: mechanism:
Tracks anisotropic water diffusion along axons
Diffusion tensor imaging (DTI): Applications (2):
(1) Mapping brain connectivity
(2) Detecting axonal damage
Computational neuroanatomy:
combines imaging techniques and computational tools for modeling and analysis
Computational neuroanatomy:
Combines imaging techniques and computational tools for modeling and analysis
Computational neuroanatomy: applications (3):
(1) disease diagnosis
(2) Studying brain plasticity and learning
(3) machine learning for neural structure
- Which of the following is not a neuroanatomical technique?
a) Histological techniques
b) Electrophysiology
c) Non-invasive imaging
d) Dye-based tracing
B) Electrophysiology
- Who developed the Nissl stain?
a) Santiago Ramón y Cajal
b) Camillo Golgi
c) Franz Nissl
d) Heinrich Waldeyer
Frank Nissl
- What is the primary target of Nissl staining?
a) Axon terminals
b) Myelin sheath
c) Rough endoplasmic reticulum (Nissl bodies)
d) Astrocyte processes
c) Rough endoplasmic reticulum (Nissl bodies)
- What type of dye is used in Nissl staining?
a) Acidic aniline dyes
b) Basic aniline dyes
c) Fluorescent dyes
d) Silver nitrate
b) Basic aniline dyes
- What is a Nissl body?
a) Cluster of mitochondria
b) Synaptic vesicle storage site
c) Aggregation of rough endoplasmic reticulum
d) Part of the Golgi apparatus
c) Aggregation of rough endoplasmic reticulum
- The Golgi stain was developed by:
a) Franz Nissl
b) Camillo Golgi
c) Santiago Ramón y Cajal
d) Rudolf Virchow
b) Camillo Golgi
- What chemical is first used in the Golgi staining method?
a) Silver nitrate
b) Potassium dichromate
c) Fluorogold
d) Cresyl violet
b) Potassium dichromate
- Which reaction forms the black deposits in Golgi staining?
a) Silver nitrate reacting with cell membrane proteins
b) Potassium dichromate reacting with lipids
c) Silver chromate precipitation
d) Fluorescence of bound dyes
c) Silver chromate precipitation
- What is the major advantage of Golgi staining?
a) Selectively stains entire neurons
b) Shows differences between glia and neurons
c) Labels only cell nuclei
d) Identifies myelin proteins
a) Selectively stains entire neurons
- Santiago Ramón y Cajal used the Golgi stain to:
a) Discover the synapse
b) Provide evidence for the neuron doctrine
c) Identify neurotransmitters
d) Classify glial cells
b) Provide evidence for the neuron doctrine
- What is the purpose of immunocytochemistry (ICC)?
a) To detect and visualize proteins using antibodies
b) To identify glial cell morphology
c) To analyze myelin thickness
d) To perform non-invasive imaging
a) To detect and visualize proteins using antibodies
- Which labeling methods are commonly used in immunocytochemistry ICC?
a) Fluorescent dyes
b) Silver nitrate staining
c) Aniline dyes
d) Golgi silver chromate
a) Fluorescent dyes
- In situ hybridization (ISH) is used to:
a) Detect protein expression in neurons
b) Detect specific mRNA sequences (which reveals that the neuron synthesizes the protein/peptide encoded by that mRNA sequence)
c) Trace neuronal connections
d) Identify axonal transport pathways
b) Detect specific mRNA sequences (which reveals that the neuron synthesizes the protein/peptide encoded by that mRNA sequence)
- Brainbow technology is used to:
a) Trace neural circuits using viral markers
b) Genetically label neurons with different fluorescent proteins
c) Visualize synaptic vesicles
d) Measure neurotransmitter levels
Genetically label neurons with different fluorescent proteins
- The Brainbow technique relies on:
a) Random recombination of fluorescent proteins
b) Silver chromate staining
c) Immunohistochemistry
d) Axonal transport
a) Random recombination of fluorescent proteins
- Optogenetics allows researchers to:
a) Control neurons with light
b) Track neurotransmitter release
c) Measure synaptic potentials
d) Detect protein interactions
a) Control neurons with light
- Viral tracing techniques help:
a) Map synaptic connectivity
b) Detect neurotransmitter levels
c) Identify gene expression
d) Analyze action potentials
Map synaptic connectivity
- Which virus is commonly used for retrograde transsynaptic tracing?
a) Herpes simplex virus (HSV)
b) Rabies virus
c) Influenza virus
d) Poliovirus
b) Rabies virus
- Which dye-based method is commonly used for neuronal tracing?
a) Horseradish peroxidase (HRP)
b) Brainbow
c) Golgi stain
d) MRI
Horseradish peroxidase (HRP)
- Anterograde transport refers to:
a) Movement from axon terminals to soma
b) Movement from soma to axon terminals
c) Diffusion of dyes across synapses
d) Viral transmission between neurons
) Movement from soma to axon terminals
- What does MRI primarily measure?
a) Neuronal firing rates
b) Magnetic properties of hydrogen nuclei
c) Glucose metabolism
d) Electrical activity
b) Magnetic properties of hydrogen nuclei
- What type of MRI technique maps white matter tracts?
a) Functional MRI (fMRI)
b) Diffusion Tensor Imaging (DTI)
c) Magnetoencephalography (MEG)
d) Golgi staining
b) Diffusion Tensor Imaging (DTI)
- DTI imaging relies on:
a) Diffusion of water molecules
b) Radioactive tracers
c) Ion channel activity
d) Myelin protein expression
a) Diffusion of water molecules
- A voxel in MRI refers to:
a) A measure of brain volume
b) The smallest unit of 3D spatial resolution
c) A type of contrast agent
d) A synaptic marker
b) The smallest unit of 3D spatial resolution
- Which of the following are limitations of MRI?
a) Can’t image white matter
b) Expensive and contraindicated for metal implants and pace-makers
c) Uses radioactive tracers
d) Requires invasive surgery
Expensive and contraindicated for metal implants and pace-makers
- Computational neuroanatomy combines:
a) Imaging and computational modelling tools
b) Golgi and Nissl staining
c) Immunocytochemistry and Brainbow
d) Dye-based and viral tracing
Imaging and computational modelling tools
- What is a major application of computational neuroanatomy?
a) Diagnosing neurodegenerative diseases
b) Staining neurons
c) Measuring neurotransmitter levels
d) Axonal transport studies
Diagnosing neurodegenerative diseases