Neurotransmitters Flashcards
Action and type of vesicle of Gaba Glycine Glutamate Aspartate NE Adrenaline Dopamine Serotonin Histamine NO Ach ATP Neuropeptides Endocanabinoids
Inhibitory; small clear Inhibitory;small clear Excitatory;small clear Excitatory;small clear Excitatory and inhibitory;small dense Excitatory and inhibitory;small dense Excitatory and inhibitory;jury is out Excitatory and inhibitory; large dense Excitatory; large dense Excitatory and inhibitory ; nothing Excitatory; small clear Excitatory; small clear Excitatory and inhibitory;large dense Inhibits inhibition; nothing
amino acids derived NTs are involved in —— synaptic transmissions while amines are involved in —— synaptic transmissions
Fast
Slow
Mention 4 ways of inactivating a neurotransmitter
it could leave the cleft to a place where it has no action
(2) could be destroyed by specific enzymes
(3) engulfed and removed by Astrocytes (macrophages)
(4) by reuptake into the axon terminal
Example of cotransmitters
Norepinephrine and adenosine
Mention the classes of receptors and define them
(1) Ionotropic receptors/Ligand gated channels: the receptor servers as the channel and gives fast post synaptic responses ;short life-span
(2) metabotropic: the receptor and the ion channels are seperate;slow response;longer life span
What is the first substance identified as NT
ACETYCHOLINE
Between the brain and NMJ,where is Ach’s job more understood
Neuromuscular junctional
Effect of sarin on Ach
inhibits Ach esterase irreversibly
What is sarin
organophosphate nerve gas
Another example of organophosphate are insecticides
Decreased Ach leads to which popular disease
Alzheimer’s
Ach is synthesized from - and - in the presence of -
-acetyl coA+ choline in presence of choline acetyl transferase
Which substrate of Ach is endogenous and which isn’t
And their source
acetyl coA (endogenous) from glycolysis -choline(exogenous)is transported with Na dependent transporter
Ach is loaded into a vesicle by?
-Ach is loaded into vesicle by a vesicular transporter
VACht
Ach has a short or long life span?
Short
Types of Ach receptors
-muscarinic-metabotropic receptors and nicotinic-ionotropic receptors
Where can you find muscarinic and nicotinic receptors
muscarinic is present on organs getting post gang para nerves and post gang sympa cholinergic nerves
-nicotinic is found in the synapse between pre and post gang para and sympa nerves. And neuromuscular junction
Effect of muscarinic receptors on dopamine transmission
muscarinic receptors(2 and 4) have an inhibitory function of dopamine-mediated motor effects while muscarinic receptor 5, potentiates the activity of dopamine
Most excitatory neurotransmitter in the CNS is?
Glutamate
Which NT is important in excitotoxicity
Glutamate
Describe excititoxicity
phenomenon that describes the toxic actions of excitatory neurotransmitters where prolonged activation of a receptor can lead to cell death)
Situations that lead to excess glutamate production
Cells release glutamate when they get damaged like after trauma, stroke,Parkinson’s,dementia or even severe convulsion
Ionic basis for glutamate causing cell death and damage
leads to swelling of cells due to excess sodium influx
leads to production of NO which could also potentiate the toxicity
over active nmda receptors lead to over influx of calcium leading to activation of protease leading to apoptosis
List the receptors for glutamate and their function
N-methyl-D-aspartate receptors: for learning and memory
The non-nmda receptors:
Kainate receptors :for fast transmission
AMPA receptors: modulate cell excitability by gating the flow of calcium and sodium ions into the cell
Major difference between AMPA and NMDA
only the sodium and potassium influx occur in AMPA receptors whereas, in NMDA receptors, calcium influx occurs in addition to sodium and potassium influx
Do glutamate have metabotropic or Ionotropic receptors
They have both
Another name for AMPA receptors
Quisqualate receptors
glutamine released by glial cells are taken into neurons by ———. Converted to glutamate by ——-. The glutamate is taken into vesicle by—— Glutamate released into cleft is taken back by either neurons or glial cells by ——
Excitatory amino acid transporter (EAAT)
Glutaminase
vesicular glutamate transporter.
EAATs
Glycine’s inhibitory powers are predominant in ?
Spinal cord and brain stem
Effect of strychnine on glycine
Strychnine is a competitive antagonist at inhibitory neurotransmitter glycine receptors in the spinal cord, brain stem, and higher centers. It thus increases neuronal activity and excitability, leading to increased muscular activity.
Glycine receptors have a nanomolar affinity for Strychnine
Glycine receptors
Ionotropic or metabotropic
Ionotropic
Fate of glycine is ———
loaded into vesicles by ——. transported into glial and NEURONES by——-
Reuptake
Vesicular inhibitory amino acid transporter
glycine transporter
Noradrenaline controls what ?
Mood, arousal, dream and sleep patterns
Difference between noradrenaline and histidine and serotonin
NE has a catechol ring
Serotonin has an indole ring
Histamine has an imidazole ring
Parts of the brain where NE can be found
Hypothalamus, thalamus,cortex,spinal cord, brainstem, basal ganglia, and locus coreulus in lower pons, mid brain(SN and VTA), amygdala, hippocampus
Steps in synthesis of norepinephrine
phe to tyr (——-)
- tyr to L-dopa(——)
- dopa to dopamine (—-)
- dopamine to NE(———)
phe hydroxylase
tyr hydroxylase
dopa decarboxylase
dopamine hydroxylase
Fates of Norepinephrine
85% reuptake by NET
Or degraded by comt and mao
Full meaning of COMT and MAO
Catechol-O-methyl transferase
Monamine oxidase
Norepinephrine is loaded into vesicles by
Vesicular monoamine transporter
Noradrenaline’s receptors are metabotropic or Ionotropic
Metabotropic
Which adrenergic receptors favor norepinephrine
Alpha 1, alpha 2
Beta 1 favors both epi and NE
BETA 2 favors epi
Cocaine works by inhibiting —-
Dopamine transporter
Amphetamines work by inhibiting—
Dopamine transporter and noradrenaline transporter
Major source of dopamine in the brains is
the substantia nigra and ventral tegmental area. Which are parts of the basal ganglia
Dopamine has 2 classes of receptors,list them
D1 class dopamine receptor (D1andD5) -D2 class dopamine receptor (D2,3,4)
Dopamine receptors
Ionotropic or metabotropic
Metabotropic
Dopamine is loaded into vesicles by
vesicular monamine transporter
Fates of dopamine
reuptake by Na dependent dopamine transporter (DAT)
Or
Degraded
Dopamine is degraded by and in what order
Comt-Mao-aldh
Mao-aldh-comt
Dopamine is degraded into
Homovanilic acid (HVA)
Main sources of serotonin
Food we eat
Raphe nucleus in brain stem
Between dopamine and serotonin
Which causes vasodilation and which causes vasoconstriction
Dopamine causes dilatation
Serotonin causes constriction
Function of serotonin
inhibits pain sensation
-cause elevation of mood and sleep
involved in vegetative functions like feeding,sleeping,sex, appetites
Mechanism of SSRI drugs
Selective serotonin reuptake inhibitors drugs inhibit the reuptake of serotonin from the synaptic cleft
They are antidepressants
Degradation of serotonin
By Mao then aldh to give indole acetic acid
Serotonin can also be converted to x
What is x
Function of x
Melatonin
Control sleep cycle
Major sources of histamine
Mast cells release histamine during tissue damage or allergic reactions
Posterior hypothalamus
Histamine is belived to play an important role in —— and —-
arousal mechanism
food intake
Histamine is synthesized from——— by ———- and ushered into vesicles by —-
histidine
histidine decarboxylase
VMAT
Histamine is degraded by either —- or ——
histamine methyltransferase then Mao-B to get N-methyl imidazole acetic acid
Or
DAO, then phosphoribosyl transferase to get imidazole acetic riboside
Histamines have metabotropic or Ionotropic receptors
Metabotropic
How many Histamine receptors have been identified and what are their functions
3
H1-for vestibular function and allergic reaction
H2-control secretion of gastric acid
H3-control histamine turnover
Which catechol amine is found in lower places of the brain and in fewer neurons compared to the others
Adrenaline
Adrenaline uses —- to enter vesicles
-uses —- too for reuptake
VMAT
NET
Most important inhibitory neurotransmitter of the CNS is ?
GABA
Receptors of gaba
GABAA-ionotropic(Ligand gated ion Channel)
GABAB-metabotropic(G coupled protein)
Valium, diazepam, benzodiazepines,barbiturates
All bind to which receptors
GABAa receptors
GABA is synthesized from ——- by ———— with cofactor——-
glutamate
glutamic acid decarboxylase(GAD)
pyridoxine
gaba is kept into vesicles by
Vesicular inhibitory amino acid transporter
GABA is ushered into glial cells by
GABA transporter
Actions of substance P
mediates pain sensation
-regulates anxiety,stress, mood disorders,neurotoxicity ,nausea, and vomitting
Source of substance P
Nerve endings of pain pathways in spinal cord
Peripheral nerves
Hypothalamus;retinal;intestine
Which neurotransmitter acts as an indirect mediator of acetylcholine’s dilator actions
Nitric oxide
NO is produced by - kind of cells ,found as —- and stored in —-
Non neuronal cells like endothelial cells of blood vessels
Found in salt form
Not stored in vesicles
Nitric oxide is formerly called?
Endothelial derived relaxation factor
Excess NO can lead to which diseases
Parkinson and Alzheimer’s
Nitric oxide stimulates the production of - and - while inside the cells
cAMP and cGMP
Cotransmitter for norepinephrine is - and not -
ATP and not adenosine
Adenosine, inhibitory or excitatory in CNS
Largely inhibitory in CNS
Caffeine works by using —— to inhibit —— receptors as a ———- antagonists
Methyxanthine
Adenosine receptors
Competitive antagonists
neuropeptides are synthesized by—— and eliminated by being degraded by—— into—-
translation process
peptidases
component amino acids
Non opiod peptides use what type of receptors
Metabotropic
neuropeptide Y inhibits release of
Norepinephrine
Effect of high dosage of opiods on pupils
high dose of opiods can cause pinpoint pupils that do not respond to light
Types of opiod receptors
3
Mu, delta,kappa
Origin of :
ENKEPHALINS
DYNORPHINS
ENDORPHINS
And the receptors they bind to
Pro enkephalins -delta
Prodynorphins -kappa
Pro opiomelanocortin -mu
Types of enkephalins
Types of dynorphins
Types of endorphins
Methionine enkephalin
Leucine enkephalin
Alpha and beta dynorphins
Alpha. Beta . Gamma
Which opiate is secreted after working out
And leads to —-
Endorphins
Joggers eye
The following pathways run from - to -
NIGROSTRIATAL
Tuberoinfundibular
Mesocortical
Mesolimbic
From substantial nigra to dorsal striatum/neostriatum
From hypothalamus to pituitary gland
From ventral tegmental area to ventral striatum (nucleus accumben+ olfactory tubercle)
From ventral tegmental area to cortex
Function of
NIGROSTRIATAL
Tuberoinfundibular
Mesocortical
Mesolimbic
the pathway modulates voluntary movement
inhibit prolactin secretion and support lactotroph (pituitary cells) proliferation
issue here causes schizophrenia . Anti psychotics are used to reduce dopaminergic activities
responsible for pleasure (reward pathway)
-drugs thatmake you feel high works here to increase dopaminergic activity
All amines are amino acids and all amino acids derivatives are amines
T/F
F
COMT degrades norepinephrine to normetanephrine
T/F
T
Effect of tyramine on someone using MAO inhibitor
Causes high blood pressure
3-methoxytyramine is one of the——- products of ——-
breakdown
Dopamine
Where can you find tyramine?
Seafood
Serotonin will prolong an AP by phosphorylation of potassium channels through the action of cGMP
T/F
F. Should be cAMP
Dopamine + COMT=____
Dopamine + MAO=——
Dopamine + Mao+comt= ——
3-methoxytyramine
Dihydroxylphenylacetic acid
Homovanilic acid
Norepinephrine + COMT=____
Norepinephrine + MAO=——
Norepinephrine + Mao+comt= ——
Normetanephrine
Dihydroxymandelic acid
3-Methoxy-4-hydroxymandelic acid (VMA)
Epinephrine + COMT=____
Epinephrine + MAO=——
Epinephrine + Mao+comt= ——
Metanephrine
Dihydroxymandelic
VMA
serotonin serves as the precursor to——— in the——-
melatonin
pineal gland
GABA can be either recycled back to the presynaptic terminal or degraded by ———to enter the ——-
GABA transaminase
citric acid cycle.
Unlike the other amino acids that serve as neurotransmitters GABA does———(i.e., it is———-)
not have any metabolic functions
not incorporated into proteins
In presynaptic nerve terminals, the enzyme —— converts —— to—— and NO.
NO synthase
arginine
citrulline
———(VIP) is stored and secreted with———
vasoactive intestinal peptide
ACh
Which comes first?
———or NE induced contraction
ATP induced contraction
Serotonin is degraded by MAO and COMT
T/F
F.
Degraded by MAO. Then aldh
ATP is degraded by ——- to ——- and ——-
Hydrolysis
AMP; adenosine
Neuropeptides are degraded by ——-
Endocanabinoids are degraded by ———
Nitric oxide is degraded by ———
Proteases
Hydrolasis by FAAH
Spontaneous oxidation
Rate limiting step of the following
Glycine production Catecholamines Serotonin NO Endocanabinoids Neuropeptides
Phosphoserine Tyrosine hydroxylase Tryptophan hydroxylase NO synthase Modification of lipids Synthesis and transport
Peptide NT usually contains —- pepetides that are each ——- long
100
3-30
synapse between the vagus nerve and cardiac muscle fibers used —— NT
Ach
Sarin was once released in———
Tokyo’s underground rail system
GABA is most commonly found in——— interneurons
local circuit
———-cells provide an example of a GABAergic projection neuron
cerebellar Purkinje
Most GABA is eventually converted
to———, which is metabolized further in the tricarboxylic acid
cycle
succinate
dopamine also plays a poorly understood role in some sympathetic ganglia.
T/F
T
Dopamine receptors are found only on the post synaptic membrane
T/F
F. Found on both pre and post
Dopamine sends fibers to the cerebellum
T/F
F
Norepinephrine sends fibers to the cerebellum
T/F
T
NET is also capable of taking up dopamine.
T/F
T
mutation in the NET gene is a cause of———, a disorder that produces——
orthostatic intolerance
lightheadedness while standing up.
Epinephrine-containing neurons in the central nervous system are primarily in the——- and in the—— and project to the—— and——
lateral tegmental system
medulla
hypothalamus
thalamus
The central histamine projections mediate——- and——, similar to central—— and——- projections.
arousal; attention
ACh; norepinephrine
Antihistamines that cross the blood-brain barrier, such as———, act as——- by interfering with the roles of histamine in——
diphenhydramine
sedatives; CNS arousal
Acetylcholine was Isolated in___ by a——- named———
1921
German biologist
Otto Loewi
Function of imipramine?
Inhibits NET
Effect of :
Resperine
Guanetheidine
Bretylium
Inhibits VMAT
Inhibits release of NE
inhibits release of NE
Is Taurine a NT
Is Alanine an NT
Yes
Yes
Effect of alcohol on glutamate receptors?
Inhibits glutamate
Alcohol effect on the following
Glutamate receptors
GABA receptors
Dopamine
Serotonin
Antagonists
Agonist
Increase quantity
Increase quantity
Does alcohol bind directly to the Ach receptors?
Yes
Serotonin is a monamine
T/F
T
CO is an NT??
Yes
Effect of nicotine on glutamate and dopamine
Increase increase
ADD is caused by low ——
Serotonin
—-is also the neurotransmitter at cells of the adrenal medulla, where it acts on ——-receptors
ACh; nicotinic ACh
Syntaxin is to ———
AS
Neurexin is to ——-
Synaptobrevin
Synaptotagmin
hemicholinium drugs can inhibit ———— ——-
Choline transporter
Function of vesamicol
Inhibit VACHT
Between SNAPS and VAMPS, which is found in the inner surface of the nerve terminal?
VAMPS
acetylcholine vesicle release process is blocked by——- toxin
botulinum
Function of Metyrosine
Inhibit tyrosine hydroxylase
