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58 Cards in this Set
- Front
- Back
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synthesis of ACh
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Acetyl CoA + choline -> acetylcholine
catalyzed by choline acetyltransferase degraded by AChE and choline is taken back up |
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examples of catecholamines
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Dopamine
Norepinephrine Epinephrine |
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synthesis of catecholamines
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In cytoplasm:
Tyr -> L-Dopa by Tyrosine Hydroxylase L-Dopa -> Dopamine by AAAD In vesicle: Dopamine -> NE by Dopamine Beta Hydroxylase NE -> Epi by PNMT |
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what differentiates a neuron that produces norepi and epi?
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the expression of PNMT. not in brain, but in the adrenal glands mainly
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what is given to parkinson's patients along with L-dopa?
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an AAAD blocker = carbi-dopa
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synthesis of serotonin
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Trp -> 5-hydroxytryptophan by Trp Hydroxylase
5-hydroxytryptophan -> Serotonin by AAAD |
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transporter for serotonin
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SERT
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transporter for NE?
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NET
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transporter for dopamine?
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DAT
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characterisitics of serotonin, NE, and dopamine transporters?
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use Na cotransport!
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what degrades serotonin, norepinephrine, and dopamine?
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MAO - monoamine oxidase can degrade
serotonin norepi dopamine |
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what are MAO inhibitors used for?
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antidepressants - block the degredation of dopamine, serotonin and norepi
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synthesis and degredation of glutamate
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glutamate diffuses out of synaptic cleft. EAAT - excitatory amino acid transporter in the glia takes the glutamate up. glutamine synthetase converts glutamate into glutamine. glutamine is exported. neuron takes up glutamine and converts it to glutamate via glutaminase. glutamate is put in vesicles and used again
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synthesis and degredation of GABA
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side product of Kreb's cycle
AKG-1>Glutamate-2>GABA-3>succinic semialdehyde-4>succinate 1. GABA-T - GABA transaminase 2. GAD - glutamate decarboxylase - needs piridoxyl pyrophosphate 3. GABA-T 4. SSADH - succinic semialdehyde DH |
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how does severe vitamin B6 deficiency cause seizures?
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vitamin B6=pyridoxal phosphate is a cofactor needed by Glutamate Decarboxylase.
If GAD cannot turn Glutamate into GABA, inhibitory neurons cannot release GABA. |
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how is CO synthesized as an unconventional NT?
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from heme via heme oxidase
CO then acts on soluble guanylyl cyclase to make cGMP from GTP |
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how is NO synthesized as an unconventional NT?
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from L-arginine via NOS (Nitric Oxide Synthase)
NO acts on soluble guanylyl cyclase which makes cGMP from GTP |
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how does viagra work?
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viagra inhibits phosphoidesterase, potentiating the vasodilatory effects of cGMP
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in what form are neuropeptides transported down the axon?
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as neuropeptide precursors.
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what kinds of vesicles contain the 2 classes on NT's?
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neuropeptides - large dense vesicles
small molecule NT - small clear vesicles |
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where is neuropeptide precursor cleaved and folded?
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w/in its vesicle at the presynaptic terminal
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how can the breakdown of a neuropeptide cause even more of a response?
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the breakdown products of a neuropeptide may be smaller, even more potent neuropeptides
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how is neuropeptide signal terminated?
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they diffuse away and are broken down by enzymatic degredation. not taken back up.
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most projection neurons use __ as a NT
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glutamate.
projection neurons reach from one area of the cortex to another. |
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major inhibitory NT used by 98% of inhibitory neurons in brain
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GABA
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major excitatory NT used by 98% of inhibitory neurons in brain
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glutamate
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major inhibitory NT in the spinal cord
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Glycine
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location of Ach neurons in brain
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striatum
septal nucleus nucleus basalis |
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NT which functions in the CNS in motor control and in the hippocampus for memory storage and recall
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Ach
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location of norepinephrine neurons in brain
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locus ceruleus
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location of serotonin neurons in brain
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rostral raphe nuclei - project to all areas of brain
caudal raphe nuclei - project to spinal cord |
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location of histamine neurons in brain
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tubomammillary nucleus of HHypothalamus
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why do antihistamines cause drowsiness?
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histamine neurons function in alertness and arousal, and energy metabolism
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NT which functions in mood and regulating sleep/wake cycles
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serotonin
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why do patients with depression often have sleep/wake cycle problems?
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serotonin which may be depleted in depression is also important in sleep/wake cycles
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NT which functions in attention, alertness, circadian rhythms, memory formation, and mood
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NE
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location of dopamine neurons in brain
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1 substantia nigra
2 ventral tegmentum - projects to amygdala, nucleus accumbens and prefrontal cortex 3 arcuate nucleus - projects to median eminence of hypothalamus 4 retina |
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NT which functions in motor control in the striatum and the reward system / motivation
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dopamine
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why do parkinson's patients often suffer demotivation?
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dopamine is responsible for reward system as well as motor control
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why would drug abuse be related to dopamine?
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dopamine is involved in the brain's reward system
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NT which functions in learning and memory, development, synaptic transmission
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NO
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NT which produces analgesia
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opiate neuropeptides
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NT that functions in neuronal survival, neuronal differentiation, and synaptic plasticity
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BDNF
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NT that functions in feeding behavior and digestion
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gut - brain neuropeptides. found in gut and brain.
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4 criteria for being a NT
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1. produced in neuron and present at presynaptic terminal
2. released in response to AP 3. causes a biological response via receptor 4. mechanism for termination |
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2 types of NT
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1. small molecule NT
2. neuropeptide |
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what type of NT are always neuromodulators vs classical NT?
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neuropeptides
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where are classic neurohormones made?
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hypothalamus
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how many types of small molecule NT's does a neuron make
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only one
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why does it take multiple action potentials to trigger release of neuropeptides?
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they do use a high affinity Ca sensor, but it sits further away from the Ca channels. senses the cell's concentration of calcium rather than microdomain. takes repetitive firing to trigger release.
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what kind of transporter packages NT's into synaptic vesicle?
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a proton - NT antiporter
does vesicle pH go up or down?? |
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what kind of transporters take NT back up into presynaptic terminal
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there is one for Glutamate and one for all other NT's. they involve co-transport w/ other ions
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what NT's are indoleamines?
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serotonin and histamine
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what NT's are made from tyrosine?
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catecholamines (dopamine, NE, Epi)
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what NT's are made from tryptophan?
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serotonin
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what transporter takes up Glutamate?
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EAAT - excitatory amino acid transporter
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what enzyme do CO and NO act on?
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soluble guanylyl cyclase
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what enzyme synthesizes NO and CO?
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NO - nitric oxide synthase
CO - heme oxidase |
