Week 1 objective-related Flashcards
What spot located under the neural plate is responsible for signaling the neural tube to close
the Notochord
What happens if the neural tube doesn’t fully close?
spina bifida or anencephaly
how do you screen and prevent neural tube defects?
AFP is the screening marker and folate must be given BEFORE conception
Before migration. neurons undergo their first mitotic birthday. Where does this occur?
In the neural tube
What cells from the neural tube maintain ability to replicate even after migrating away from the neural tube?
Glial cells
Floorplate becomes dorsal/ventral
Roofplate becomes dorsal/ventral
Roofplate is future dorsal (alar)
Floorplate is future ventral (basal plate)
What are the steps in making neuronal connections
neuronal migration
Trophic factors
Synapse Elimination (plasticity)
Maturation of neuronal connections
The cortex develops with the help of what cells that help guide neurons at the inner zone to keep growing out?
Radial glial cells
“inside out” development of the cortex
What produce the trophic factors?
The neuronal targets
what genes guide segementation
HOMEBOX
What are the 3 main trophic factor families you should know
NGF
BDNF
NT-3
NGF populates what neurons?
Sympathetic
Nociceptive
Cholinergic basal forebrain
BDNF, NT-4/5 neuronal population?
motoneurons (alpha) vestibular sensory peripheral sensory cranial ganglia cortical neurons
NT-3
Proprioceptive sensory
Motorneurons (gamma)
Cranial ganglion (nodose)
Corticospinal neurons
Neurotrophic actions are mediated when receptor-ligand complexes move from where to where
From the periphery toward the soma, so it’s altered anytime retrograde transport is affected
If there isn’t a target for a neuron to innervate what happend?
NOCD
Congenital Insensitivty to Pain with Anhidrosis is related to what part of the trophic factor pathway?
LOF mutation resulting in developmental apoposis of specific neuronal population (TrkA mut)
This is a loss of NGF-dependent primary sensory neurons and postgang symps
Lissauers and spinothalamic tract indiscernible at autopsy
You can give trophic factors to help repopulate neurons. Where would these trophic factros act?
On the target
ex: GDNF = VEGF increases survival
Anterograde transport utilizes which intermediate filament?
Kinesin
Retrograde transport (movement toward the cell soma) utilizes what intermediate filament?
dynein
fibrous astrocytes have fine long straight processes and they’re found in
white matter
protoplasmic astrocytes have wavy thin fluffy processes and are found in
gray matter
åstrocytes have many important functions including electrolyte balance particularly regarding which ions
K+
oligodendrocytes can myelinate many or few internodes?
up to 50
Schwann cells are of ______ orign
neural crest
Microglia are of ______ origin
mesodermal
Are the endothelial cells or the astrocytic foot processes the ones that prevent easy diffusion/transport to form the blood brain barrier?
The specialized endothelial cells are the ones that have the zonula occludens.
Fluid path of the CSF
Lateral Ventricle 3rd vent Cerebral aqueduct 4th Ventricle Subarachnoid space Arachnoid granulations Venus Drainage
Choroid plexus is derived from the
ependyma`
Transduction of a sensory stimulus leads to a generator ______
generator potential
What mechanoreceptors are slow adapting? Fast?
Meisner
Pacinian is fast (adapts quickly over time, no longer firing/ sensing it as time goes by
What aspect of neuronal layout allows us to sense location/physical mapping?
REceptive Fields
smaller= higher acuity
more overlap= higher resolution
What is the labelled line theory of sensory code?
That axons are specifically coded to respond to specific stimuli
Exteroreceptors and their stimuli?
Meissner’s: touch
Merkels: touch
Hair cells: touch
Krause end bulbs: pressure and vibration
Ruffini endings: stretch
Proprioceptors that convey state of internal
Pacinian Corpuscles
Joint REceptors
Muscle Spindles
Golgi Tendon ORgans
Discriminative touch receptors are all innervated by what type of fiber?
A-beta
A fast adapting receptor like Pacninan will show hat type of neural activity over time?
it will show activity at the onset of the stimulus and then no activity
Pain and temperature are transduced by free nerve endings which are conducted on what fibers? What do the membrane receptors react to?
Alpha delta, C
PG, histamine, substance P to respnod to tissue damage
What are the predominant stretch receptors iwthin the muscles?
muscle spindles
Efferent and afferent innervation of muscle spindle cells
efferent: gamma
afferent: Ia (primary), II (secondary)
Proprioception golgi tendon organs
Extrafusal muscle fibers contract
This stretches eleastic fibers of GTO
Ib afferent nerve endings are deformed
Increased depolarization of nerve endings
Increase in Ib afferent firing
Glutamate receptor subtypes?
AMPA/kainate
NMDA
Metabotropic
GABA recetptor subtypes
GABA (A and B)
in the retina: GABA (C)
ACh receptor subtypes?
Nicotinic
Muscarinic (parasympathetic ganglia)
Muscarinic and Nicotinic in brain
NE receptor subtypes?
alpha and beta
Dopamine receptor subtypes?
D(1-5)
Serotonin receptor subtypes?
5-HT subtypes
Direct Gating (Ionotropic ligand-gated receptors) include, these are fast whereas indirect are slower but have longer effect
Glutamate, ACh, GABA, glycine, Serotonin
this is when a neurotrasmitter binds and opens up an ion channel within the membrane
Choline acetyletransferase is important for
combining Acetate and 3-c backbone to Acetylcholine
Tyrosine is a precursor for which neurotransmitters?
NE
Dopamine
Dopamine increase blood flow to
Kidneys
Serotonin is found throughout the ____ tract
GI
The glia maintain appropriate levels of what major excitatory neurotransmitter?
Glutamate
What’s important to note about the post-synaptic receptors of GABA?
needs 2 GPCRs to dimerize in order to work.
ACh M1 and nicotinic receptors are excitatory for different reasons. Why
M1-R decrease K= conductance which prevents hyperpolarization after the action potential and increases IP3 and DAG
Norepinephrine excitatory and inhibitory receptors?
Alpha 1= excitatory by decreasing K conductance
Alpha 2 inhibitory by decreasing presynaptic calcium conductance and increasing postsynaptic potassium conductance, decreasing cAMP
Beta are GPCR that ca do both
Dopamine excitatory and inhibitory receptors?
D1 excitatory
D2 inhibitory
5-HT2A, 3, 4 are all
excitatory
opioids binding to mu, delta, kappa are
inhibitory via decreasing of Ca, cAMP, potassium
opioid peptides
Enkephalin
Endorphin
Dynorphin
Sites of action for opioid analgesics
Primary Brainstem/medullary centers (Periaqueductal grey matter, nucleus Raphe, magnus)
Limbic system targets
Spinal cord
Periphery