Chapter 1 Flashcards
What structures make up the CNS?
brain, spinal cord, white and gray matter
What structures make up the PNS?
nerves and ganglia
Afferent neuron
sensory, towards CNS
Efferent neuron
motor, away from CNS
Enteric
neurons that control the digestive system
Neuron doctrine
individual neurons working together
Reticular (Golgi) theory
NS is one big, continuous system
What type of neurons make up the dorsal root/cranial nerve ganglia?
sensory pseudounipolar neurons
Autonomic ganglia
2-neuron chain from CNS to target
Pathway of signaling between neurons
always afferent -> interneurons -> efferent; mostly in CNA, short axons, inhibitory or excitatory
Parallel processing
processed at the same time
Convergent processing
receives many inputs that converge to a single synpase
Divergent processing
makes synaptic contact with a large number of other neurons
Explain the reflex/inhibition process
quads are stimulated/contracted and hamstring is relaxed/inhibited
Which way does sensory info enter?
Enters through dorsal root and synapses in dorsal/posterior gray matter
Which way does motor info enter?
Through the ventral horn and leaves through ventral root
What forms spinal nerves?
Dorsal and ventral roots coming together
Characteristics of a neuron
polarized, conduct electrical signals
Multipolar
single axon and many dendrites
bipolar
axon and dendrite extending from body in opposite directions
pesudounipolar
single axon that splits into 2 branches
unipolar
one axon one dendrite
anaxonic
lacks axon or indistinguishable from dendrite
Glial cell functions
- maintain ionic mileu (concentration of ions)
- uptake and metabolism of neurotransmitters
- provide scaffolding for neuronal migration
- hasten propagation of impulses
astrocytes
blood brain barrier
oligodendrocytes
myelinate CNS axons *not every axon myelinated
schwann cells
covers all PNS axons *but being covered doesn’t = myelin
microglia
macrophages, immune cells
nodes of ranvier
gaps on an axon where there is no myelin
in situ hybridization lab technique
- specific for RNA, but mRNA is not always translated to transcribe proteins
silver salts or golgi staining
stains neurons randomly but has to be a dead cell
nissil staining
stains DNA and RNA
Transgenic reporter gene (GPF)
requires gene manipulation but good for specificity
Antibody staining (against TrkB)
- can be used on tissues
- for identifying expressed proteins
CT scan
- quick, cheap, good for locating tumors
- exposure to radiation and not as precise
MRI
- uses magnetic spin of H+
- better resolution
- long and expensive
Extracellular recording
- measures action potentials using electrodes
- cannot detect small changes
Calcium imaging
- dyes Ca+ with fluorescence
- time sensitive
Intracellular recording
- detects smaller changes in electric signals and precise timing
- can record synaptic and receptor potentials
- damages neuron
EEG
- measures broad changes in brain activity
- precise timing and spatial resolution
- used for seizures and sleep/wake assessment
MEG and MSI
- magnetic fields and image mapping
- excellent temporal resolution (better than EEG)
Lesion studies
precise destruction of brain tissue
Ablation studies
loss of function from surgical removal of certain parts of the brain
PET
- tracking glucose while subject performs a task
- difficult injection, risk of radioactivity
fMRI
- metabolically active areas/blood flow
- safer than PET
- poor temporal resolution
Optogenetics
- opsin activation that can monitor action potentials
- inexpensive
(think picture of the mouse)
Transcranial Magnetic Stimulation
used to treat depression and migranes
How does Cre/lox work?
loxP added to gene of interest, and with expression of Cre recombinase loxP is cut out and not expressed
CRISPER
used to introduce mutations to a target gene
Center-surround
determines the receptive field of a sensory neuron
synaptic (graded) potential
makes communication between nerve cells possible.
Neuropil
region where most synaptic activity occurs
What is gray matter made up of?
Cell bodies
What is white matter made up of?
Myelin
Where is trigeminal ganglia found?
cranial nerve
