CNS
brain and spinal cord
structure of brain
cerebral cortex basal ganglia hippocampus amygdala thalamus hypothalamus cerebellum midbrain pons medulla
brain stem
midbrain
pons
medulla
PNS
nerves and ganglia
nerves
bundles of axons
ganglia
clusters of nerve cells
coronal sections
section planes perpendicular to the anterior-posterior axis
sagittal sections
section planes perpendicular to the medial-lateral axis
horizontal sections
section planes perpendicular to the dorsal-ventral axis
axon
neuronal process that extends far past the cell body
delivers info
the transmission component of a neuron
dendrite
neuronal process that is close to the soma
receives info
is one of the receptive components of a neuron
dendritic spine
structure on a dendrite that functions in cell-cell info transfer
major types of glia
oligodendrocytes
Schwann cells
astrocytes
microglia
oligodendrocytes
glia that forms myelin sheath around axons in the CNS
astrocyte
glia that are key in development and regulation of neuronal communication
microglia
glia that engulf damaged cells and debris and reorganize neuronal connections
the immune cells of the nervous system
white matter
oligodendrocytes and myelinated axons
gray matter
neuronal cell bodies dendrites axon terminals neural connections astrocytes
cell theory
all living organisms are composed of cells as basic units
reticular theory
a net of nerve cells make up the working unit of the nervous system
disproved by the neuron doctrine
Golgi staining method
neural tissue soaks in silver and potassium dichromate solution in the dark
a small number of nerve cells obtain black precipitates
the entire nerve cell is visible in its native tissue
allowed the entire morphology of individual neurons to be seen for the first time
neuron doctrine
neuronal processes form intimate contact with each other, with communication between distinct neurons occurring at synapses
synapse
site where info is transferred from one neuron to another neuron or muscle cell
Santiago Ramón y Cajal
primarily developed the neuron doctrine
concluded that individual neurons are embryologically, structurally, and functionally independent units of the nervous system
Camillo Golgi
discovered the Golgi staining method
Matthais Schleiden and Theodor Schwann
developed the cell theory in 1938
growth cone
structure that leads developing neuronal processes to their final destinations
electron microscopy
technique allowing visualization of structures with nanometer resolution
observations with it proved that neuronal processes don’t fuse with each other
chemical synapse
junction where communication between neurons is controlled by neurotransmitter release
synaptic cleft
space that separates a neuron from another neuron or muscle cell
synaptic vesicle
fuses with the plasma membrane when stimulated and releases neurotransmitters into the synaptic cleft
located in the presynaptic terminal of a neuron
postsynaptic specialization
structure that is enriched neurotransmitter receptors
gap junction
channel formed by each neuron contributing protein subunits to form a pathway linking their cytoplasms
macromolecules can’t pass through them
pyramidal neuron
has pyramidal cell body with an apical dendrite and several dendrites with extensive branching
electrical synapse
cell-cell junction enriched in gap junction channels allowing ions and small molecules to travel from neuron to neuron
basket cell
neuron that wraps its axon terminals around the cell bodies of Purkinje cells
Purkinje cells
pyramidal cells in the cerebral cortex
motor neuron
neuron that extends dendrites within the spinal cord and projects its axon out of the spinal cord into the muscle
sensory neuron
extends a single process that splits into a peripheral axon with terminal endings and central axon that projects into the spinal cord
multipolar
neuron that has multiple dendrites and an axon
bipolar
neuron that has one dendrite and one axon
pseudounipolar
neuron that has one process that splits into peripheral and central branches
theory of dynamic polarization
the transmission of neuronal signal takes place from the dendrites and cell bodies to the axon
unipolar
neuron with a single process that ends with dendritic and axonal branches
occasionally the same branches can send and receive info
what every neuron has
receptive component
transmission component
effector component
receptive component
cell body and dendrites
effector component
axon terminals
sensory system
info flows from the sensory organs to the brain
motor system
info flows from the CNS to the periphery
what the ideal aminal model has
simple genome
short generation time
complex brain functions
easily identifiable neurons
why invertebrates are used as models for research
small number of neurons
large size
stereotyped arrangement
connectome
a representation of the complete set of synaptic connections among a group of neurons
ethical practices for research
replace animals with non-aminal systems whenever possible
use the smallest number of animals necessary to obtain the desire info
use all possible methods to minimize pain and distress to animal models
Remak schwann cells
glia that segregate individual axons in unmyelinated neurons
cytoplasms extend in between individual axons to form a Remak bundle
type III neuregulin-1
Nrgl-III
axon cell surface protein that helps determine the degree of myelination in PNS
demyelinating disease
disease where damage to the myelin sheath decreases resistance between nodes of Ranvier and disrupts organization of ion channels in the nodal region
multiple sclerosis
disorder where immune cell attack of myelin causes inflammatory plaques in white matter
most common demyelinating disease in CNS
Charcot-Marie-Tooth disease
CMT
inherited disorder that causes age-progressive deficits in sensation or movement where distal limbs have the most severe deficits
most common demyelinating disease in PNS
CMT1A
disease that results from duplication of the Pmp22 gene, causing over expression of the peripheral myelin protein
CMT1B
disease that results from mutation in the Mpz gene, causing defective myelin and axons, and myelin degeneration
myelin protein zero
Mpz
transmembrane protein in Schwann cells that regulates the joining of membranes
CMT1X
disease caused by a mutation in the Gjb1 gene
Gjb1
gene that encodes gap junction channels
Schwann cells
glia that forms myelin sheath around axons in the CNS
