Neurohistology Flashcards
What are the types of cells found in the nervous system?
neurons, glia cells, specialized cell types
What are the steps for histology sample preparation?
fixation (tissue is preserved), cutting, stretching, archive
What are histological stains?
they help visualize specific aspects of brain tissues, by staining using chemicals, solvents, fixatives
Looking at a histological stain of a spinal cord how can you tell the difference between the neurons types?
motor neurons have bigger cell bodies (located in ventral horn), sensory neurons have smaller cell bodies (dorsal horn)
What is electron microscopy?
highest resolution imaging you can do in cells, uses beam of electron to magnify image
How can you tell you are looking at an image of a synapse?
two large blocks that have a small gap between them, one has lots of small dots (presynaptic) and the other doesnt (postsynaptic)
What are some applications of immunohistochemistry?
diagnostic of abnormal cells like cancer, and the localization which provides potential information about role and function
What are some limitations of immunohistochemistry?
background staining (not specific can colour other things), and cross reactivity because of structural similarities
What is immunofluorescence?
allows visualization of many components in tissues/cells, works through broad combinations of specific antigens tagged with fluorophores
What is the difference between direct and indirect immunohistochemistry?
indirect uses an unlabeled primary antibody against the target antigen in the tissue and a labelled secondary antibody
direct uses a primary antibody that is labeled and applied to the tissue
How does fluorescent microscopy work?
by combining magnifying properties of a light microscope with the fluorescent emitting properites of compounds
What type of neuron doesn’t have axons?
retinal amacrine cell (b/c collects info and delivers to local neurons)
What are axons a hallmark of?
excitatory neurons
What type of neuron has a lot of dendrites and looks like a tree?
purkinje
What type of interneuron has a long axon? What about short axons?
relay interneurons, local interneurons
What is translation vs transcription?
mrna to protein vs dna to mrna
What does the golgi apparatus do?
modifies and packages proteins
When looking at a picture of a nucleus what are the holes pictured?
nuclear pores, allows for mRNA to leave to other things to exit/enter
What makes myelin in CNS vs PNS?
oligodendrocytes vs schwann cells
What do microtubules do in the axon?
transport highway for proteins to get to synaptic terminal and for proteins to get from synapse to cell body
How many axons can schwann cells cover?
only 1, also only doe sone section of axon, need multipl to cover entire axon
How many axons can oligodendrocytes cover?
can cover many at the same time
What are the gaps in myelin sheath called? What is the function?
nodes of ranvier, ions can leave and enter from these points which helps propogate signals
