Unit 3: Neurons and Glia

Neurophilosophy

No separation of mind and brain

Glia

insulate, support, and nourish neurons

neurons

information processing, sense environmental changes, communicate changes to other neurons, and coordinate the bodies response

How neurons communicate

by contact

Histology

microscopic study of tissue structure

Nissl stain

distinguishes between neurons and glia

golgi stain

revealed cell body, soma, neurites, axons, and dendrites

Microscopy

microscope that uses light, electrons, and fluorescence

what does the soma contain

cytosol, organelles, cytoplasm

cytosol

watery fluid inside cell

organelles

membrane enclosed structures inside soma

cytoplasm

contents within a cell

nucleus

gene expression, transcription, RNA processing

the soma

ribosomes the major site for protein synthesis

neuronal membrane

barrier that encloses cytoplasm

cytoskeleton

internal scaffold of neuronal membrane

three structures of cytoskeleton

microtubules, microfilaments, neurofilaments

the axon

cable that sends eletrical impules to sites in the nervous system

different parts of the axon

axon hillock, axon proper (middle), axon terminal

synapse

electrical-chemical-electrical transformation

axonal transport

mechanism for moving materials on the axon

anterograde transport

soma to terminal

retrograde transport

terminal to soma

dendrites

antennae of neuron

how dendrites recieve signals

postsynaptic (recieves from axon terminal)

unipolar

single neurite

bipolar

two neurites

multipolar

more than two neurites

stellate cells

star shaped cells

pyramidal cells

pyramid shape cells

according to the neuron doctrine how do neurons communicate

contact between cells

what do dendritic spines primarily function as

postsynaptic signal receptors

sensory neurons

recieve information from outside world and within our bodies

sensory neurons are usually..

unipolar

motor neurons

transmit commands from CNS to muscles and glands

Motor neurons are…

multipolar and stellate or pyramidal

interneurons

act as bridges between sensory and motor systems

interneurons are usually

multipolar

what are interneurons bipolar

in eyes and ears

astrocytes

type of glia that fill volume between neurons and influence neurite growth

role of astrocytes

formation, maturation, and elimination of synapses throughout the brain (synaptic pruning)

synaptic pruning

elimination of synapses throughout the brain (done by astrocytes)

myelinating glia

oigodendroglia, schwann cells, insulate axons

oligodendroglial cells

produce axonal meylin in the CNS

node of ranvier

region where axonal membrane is exposed

microglia

immune first responders and housekeepers of the brain. remove debris of dead cells

ependymal cells

direct cell migration during brain development

vasculature cells

deliver essential nutrients and oxygen to neurons via blood

transgenic

genes are introduced into the genome of an aminal and passed along to offsprin

cre-loxp mice

1. insert a trasngene specific to certain neurons and link it to the enzyme Cre recombinase

2. in anothe rmouse insert loxp sites that surround the gene you want to remove

3. cross the two types of mice

   1. cre will cut at loxp sites removing the gene of interest

   2. homozygotes will lose both copies of the gene

recombinant knockout mice

embyronic stem cell with removed gene injected into fertilized cell and then micebred over generations to achieve complete knockout

CRISPR

parts of bacterial immune system that can cut DNA like scissors more precisecly than before

what is the primary function of loxP sites

to mark specific DNA regions for potential removal

which genetic engineering technique allows multiple genes to be introduced intoan organisms genome

transgenic modification

disease of an axon causes

acute motor axonal neuropathy

Acute motor axonal neuropathy (AMAN)

motor neuron axons are destroyed by the immune system

disease of dendritic spines

schizophrenia and alzheimers

neurodegenerative diseases

alzheimers, parkinsons, ALS