Selected Topics - Von B Flashcards
What are some examples of neuromodulatory systems?
noradrenergic (locus coeruleus)
cholinergic (basal forebrain)
serotonergic (brainstem)
What is the locus coeruleus?
a nuclei in the pons involved in stress and panic
Where do the projections of the locus coeruleus go?
forebrain and brainstem
What does the locus coeruleus do?
puts the forebrain in the corrects state to ready it for collection and processing of info.
The LC processes (relevant/all) sensory information
relevant!
LC is involved in experience (dependent/independent) alteration in neural function and behavior.
depedent
makes the brain ready for what you are experiencing
(blank) supports navigation through a complex world.
locus coeruleus
What kind of sucks about the LC?
it contributes to cognitive issues or arousal dysfunctions associated with a variety of psych disorders
What are some disorders that the LC may make cognitive issues or arousal dysfunctions?
ADHD, sleep and arousal disorders, affective disorders, PTSD
T/F LC is used as a pharmacological target for treatment of ADHD, sleep arousal disorders, affective disorders and PTSD
T
What is the source of noradrenergic signaling?
locus coeruleus
What is the source of cholinergic signaling?
basal forebrain
What is the source of serotonergic signaling?
brainstem
What is the purpose of the BBB?
to make a stable environment for neurons
exclude toxic substances/removal of brain metabolites
protect neurons from circulating neurotransmitters
What does a brain capillary have that a general capillary does not?
basement membrane, astroglial process, pericytes, tight junctions, mitochondrias
The BBB requires (blank) signals
brain-derived (astrocytes)
Neurons exposed to the environment without a BBB last how long?
6 weeks
i.e taste and smell
general capillaries are (leaky/tight)
leaky
Brain capillaries are (leaky/tight)
tight
Do the endothelial cells or the astrocytes play the greatest role in signaling changes in the permeability of the blood brain barrier?
endothelial cells
Do the junctions of adjacent endothelial cells in brain capillaries touch or overlap?
overlap
How do we transport through the BBB?
if lipid soluble-> diffusion
if not-> receptor-mediated transport
ion channels
Can you move amino acids across the BBB?
yes
What converts L-DOPA into Dopamine?
endothelial cells
What are the ways you can get facilitated diffusion across the blood brain barrier?
L system
Glut1
What are the ways you can get active transport across the blood brain barrier?
Na/K ATPase A system (sodium glycine symporter
T/F you can move entire cells through the arachnoid granulations
T
What molecules flow into the ventricles?
Cl
K
T/ F an entire cell can pass through an arachnoid granulation
T
How is CSF absorbed?
via bulk flow through arachnoid granulations
What are the bulk flow methods for which CSF is absorbed?
vacuole transport, pinocytosis
What are the cells that act valves for one way flow of CSF?
arachnoid cells
T/F there is a barrier between the brain parenchyma and the CSF
F
T/F there is a barrier between venous blood, arterial blood, and CSF
T
What are circumventricular organs?
organs in the brain that do not have a BBB
What are the circumventricular organs?
pineal gland, subcommisure organ, area postrema, neurohypophysis, median eminence, organ vasculosum
The circumventricular organs (aka organs without BBB) serve what purpose?
endocrine or sensory (sense whats going on in blood stream)
What is considered the “vomit center” because it detects noxious or toxic stimuli in the blood stream?
area postrema
Since you have leaky blood vessels within the circumventricular organs, why doesnt it freely diffuse to other parts of the brain?
because the area is closed off by tanycytes
What is the median eminence?
is a part of the hypothalamus from which regulatory hormones are released. It is of great physiological importance, as it is integral to the hypophyseal portal system, which connects the hypothalamus with the pituitary gland.
What is the median eminence and neurohypophysis leaky instead of having a bbb?
so we can get the hormones from the hypothalamus to the rest of the body
What is the lymphatic system and mechanical cushion for the brain?
CSF
What are the homeostatic functions of the CSF?
pH of CSF
pulmonary ventilation
cerebral blood flow
Which has more protein, serum or CSF?
SERUM BY THOUSANDS of mg/dL
Which has a greater osmolarity CSF or serum?
they are equal at 295
Should you have WBC in CSF?
Should you have RBC in CSF?
very few
NO
What is the total CSF volume?
140 ml
What is the total CSF production per day?
about 500 ml
What do brain tumors do to the BBB?
it disintegrates it (maybe due to messed up astrocytes)
i.e vasogenic edema
What can bacterial meningitis cause?
damaged BBB due to inflammation
What is the one good thing about bacterial meningitis?
since it makes your BBB leaky, antibiotics can get in there and do their work
damaged brain areas are a target for (blank)
stem cells
When do you want to do a lumbar puncture?
obtain pressure measurements and samples of CSF for measurement
admin spinal anesthetics or reduce CSF pressure
inject radiopaque substance (myelography) or radioactive agent
do stem cells help Cerebral palsy?
no, there are some animal studies that show acute CP can be helped a little but definitely not chronic, which is the only kind humans have
Also there are bad SE in 5%: encephalopathy, viral infection, tumor AND you need immunosuppressants
What are the possible mechanisms of stem cells and CP?
Neuronal cell replacement Glial cell replacement Blood vessel regeneration Protection of already existing cells (stimulation of growth factor expression) Blockade of inflammatory cells (not really proven)
What are the current stem cell trials being used?
umbilical cord stem cell with intravenous and intrathecal
not really proven
Do stem cells and hyperbaric oxygen work to fix CP?
no, just wishful thinking
