Lecture 1- Neuronal signaling Travers Flashcards
interneurons are located in the …. and they function as integrators and switches
CNS
Afferent neurons have cell bodies in the … and transmit info to the…
PNS
CNS
Efferent neurons have cell bodies in the … but transmit info to the ….
CNS
effector cells
Neurons account for … % of cells in CNS and glial cells account for…%
10%
90%
Schwann cells are glial cells of the
PNS
Oligodendrocytes, microglia and astrocytes are glial cells of the
CNS
… provide myelination in the CNS
oligodendrocytes
… are macrophage like glial cells of the CNS that have an unreactive and a reactive state
microglia
…. are glial cells of the CNS that regulate extracellular fluid , provide metabolically for neurons and form the blood brain barrier
astrocytes
schwann cells provide myelin to how many axons?
1
there can be many schwann cells per axon
oligodendrocytes provide myelin to how many axons?
many
what are 2 types of peripheral demyelination?
- guillain-barre syndrome (autoimmune disease)
2. nerve trauma
Microglia are kept unreactive by the neuron by …
glycoprotein (CD200)
Neuronal injury releases intracellular ATP inducing…
motility (chemotaxis)
what are the motor proteins involved in anterograde axonal transport?
kinesins
Anterograde transport in the axon can be fast which is at a rate of…. for organelles such as neurotransmitter vesicles or it can be slow which is at a rate of…. for structural proteins
400 mm/day
0.2-2.5 mm/day
the motor proteins for retrograde transport are called… and their transport speed is…
- dyneins
- 400mm/day
Retrograde axonal transport is from the axon terminal to the cell body but this kind of transport can be negative because it can bring in….
unwanted entities such as viruses (herpes, polio, rabies)
Herpes simplex virus type 1 is easily transmitted via…. and up to …% of the adult population is infected but they are usually…
oral contact
75
asymptomatic
Herpes is transmitted…. where it remains latent in ….
During latency, virus is …. quiet
retrogradely
trigeminal ganglion
transcriptionally
In infants, herpes virus can go beyond ganglia and cause…
encephalitis
The herpes virus can be activated by fever, sun, cold, trauma, stress and then it is transmitted… to peripheral tissue, lips, and palate creating painful blisters
anterogradely
Do damaged CNS neurons regenerate?
no
Axons of damaged CNS neurons will produce…. but they do not reach their targets
sprouts
What prevents sprouts in damaged CNS neurons to reach their targets?
scar formation
In the CNS, astrocytes make…. that inhibit neuron growth
chondroitin sulfate proteoglycans
do schwann cells promote axonal regeneration in the PNS?
yes
in response to severe nerve injury, first there will be a lesion and there will be either…. or…. degeneration which will then lead to cell death followed by…. and….
- anterograde (wallerian)
- terminal
- transganglionic degeneration
- transynaptic degeneration
In a less severe nerve injury , the injured cell will undergo….
chromatolysis
Chromatolysis is associated with…. and you see physical changes in the injured cell such as…
- protein synthesis
- cell body swells and eccentric nucleus
In nerve injury, schwann cells proliferate and produce… for substrate for regenerating axons. Schwann cells also secrete… which is transported to ganglion cell body and acts for signal of protein synthesis
- Laminin
- Nerve growth factor
Nerve growth factor in nerve injury regulates… and promotes…
gene expression
sprouting
What is synaptotagmin
Calcium sensitive docking proteins for vesicle fusion and release
What are the 2 types of postsynaptic receptors?
- ionotropic
2. metabotropic
Ionotropic postsynaptic receptors are directly…
gated
Metobotropic postsynaptic receptors involve a …. and…
G protein and 2nd messenger
A postsynaptic potential is only…. mV so it is the combined effects to excitatory and inhibitory synaptic input that determines whether threshold is reached
0.5
… summation is adding together of PSPs from one synaptic contact (over time)
temporal
… summation is the adding together of PSPs produced by different synapses
spatial
acetylcholine is synthesized from … and…. by…. in synaptic terminal
choline and acetyl coenzyme A by choline acetyltransferase
action of acetylcholine is stopped by diffusion and degradation by…
acetylcholinesterase
choline reuptake is by the… neuron
presynaptic
Neurons that release acetylcholine are … neurons, neurons in … and… and preganglionic… neurons and all postganlionic…
- motor
- nucleus basalis and pons
- symp and parasymp
- parasympathetic neurons
acetylcholine binds to … and … receptors
muscarinic and nicotinic
muscarinic receptors are blocked by …
atropine
muscarinic are found in …
both CNS and PNS
when ach binds to a muscarinic receptor, it triggers…. that open or close ion channels
G protein
can be hyper or depolarizing
nicotine receptors are found in
both CNS and PNS
When ach binds to nicotine, it …. within receptor.
opens ion channel
channel permeable to Na and K
nicotinic receptors are blocked by
curare
2 locations of ach neurons in CNS
- basal forebrain- cognitive function
2. pontine nuclei- sleep regulation
2 acetylcholine diseases
- myasthenia gravis
2. alzheimers
Myasthenia gravis is an autoimmune disorder in which individual makes antibodies to…. receptors
nicotinic
Myasthenia is characterized by…. and is treated with…
- muscle weakness
- acetylcholinesterase inhibitors
alzheimers is the most common form of… and its etiology is…
- dementia
- unknown
alzheimers is a loss of neurons in … leading to decrease in cholinergix activity in cortex
nucleus basalis
biogenic amines are synthesized from…
amino acids
examples of catecholamines are… which are synthesized from the amino acid…
- dopa, epi, norepi
- tyrosine
catecholamine life cycle
- synthesis- presynap term, stored in vesicle
- release- Calcium dependent
- termination of action- presynaptic reuptake or degradation
catecholamines are degraded by…
Monoamine oxidase (MAO)
MAO (monoamine oxidase) inhibitors ….
prolong catecholamine activity which is therapeutic for mood disorders
receptors for catecholamines are almost exclusively…
G protein coupled receptors
The …area is associated with reward and addiction
ventral tegmental
Cocaine and amphetamine prolong…. action at synapse in the ventral tegmental area
dopamine
The…. is associated with the motor system: loss of dopamine associated with…. : L-dopa given therapeutically
substantia nigra
parkinsons disease
Two main groups of dopamine receptors
- D1 which activates….
- D2 which inhibits…. (leading to hyperpolar)
adenylate cyclase
Many drugs block…. receptors (ex. antidepressants, antiemetics: these drugs can cause Tardive dyskinesia)
D2
NE neurons include
sympathetic postganglionic neurons (and some CNS)
Noradrenergic receptors are….
G protein coupled
Receptors of NE are….
alpha 1 and 2
beta 1, 2, and 3
NE:
alpha 1 receptors response:
intracellular release Calcium (excitatory)
NE:
alpha 2 receptors response:
open K channels or block Calcium (inhibitory)
which is inhibitory? alpha 1 or 2
2
NE:
beta receptors 1,2,3 response:
open calcium channels
… receptors constrict veins
alpha 1 and 2
… receptors dilate veins
beta 2
location of brain assoc with norepi
locus ceruleus: attention/sleeo
location of brain assoc with serotonin
rostral raphe nuclei: sleep/mood/homeostasis
caudal raphe nuclei: sensori-motor function
serotonin is synthesized from…
tryptophan
for serotonin, there are… receptor subtypes and most at …
16
G protein coupled
…. are target of mood altering drugs
5-HT synapses
Histamine is derived from…. and found only in small populations of hypothalamic neurons… its receptors are….. and it is involved in…
histidine
G protein coupled (H1-H4)
sleep-wakefullness
Excitatory amino acids are….
glutamate and aspartate
GLutamate and aspartate bind several classes of ionotropic receptors such as… which have channels permeable to Na K and Ca
AMPA
Kainate
NMDA
GLutamate and aspartate also bind… receptors
metabotropic (g protein coupled)
The NMDA receptor is involved in functions that …
last ( memory formation, chronic pain)
Excessive excitation of NMDA receptor can cause
cell death (epilepsy, trauma, stroke)
…. can be elicited by activated NMDA receptors
long term potentiation
