Neurotransmitters Flashcards
NT:
NT - pass what, attach where
alpha 1-2, beta 1-3, betablockers
receptors
- presynaptic: what
- serpentine: via (2), secondary, where
- nicotinic: where, secondary
- M1: via (1), secondary
- M2: effect (2=1=1), nerve
homologous vs. heterologous desensization
reuptake mechanism - purpose (2)
- NT: pass along space between cells; attach to receptor in postsynaptic
- alpha 1 (respiratory), alpha 2 (vessels), beta 1-2 (cardiac), beta 3 (GI)
- betablockers = prevent norepinephrine binding = lower HR
receptors
- homologous desensitization: to 1 NT
- heterologous: to multiple NT
- reuptake mechanism: terminate/prolong AP
presynaptic
- automatic; shuts down NT to ensure 1 AP only
serpentine
- via G-protein & protein kinase
- uses secondary messenger
- in membrane
nicotinic
- in skeletal
M1
- via G-protein, secondary
M2
- dec cAMP & inc K = repolarize = bye cardiac muscle
- vagal massage
NT: Ach
size, many where, used in/where (6)
how to make - 1+1+1 + where
how to break + why + where
muscarinic (4), nicotinic (1)
used in/where: CNS, ganglion
- small vesicle
- many in cholinergic neurons
- choline + acetyl CoA + choline acetyltransferase at presynaptic
- breakdown via cholinesterase at postsynaptic to repolarize
- used in CNS, PNS, renshaw, autonomic ganglion, auditory & visual systems
receptors
- muscarinic: M1 (brain), M2 (cardiac), M4 (pancreas), M2&4 (smooth muscle)
- nicotinic: skeletal muscle
NT: NE, E, DA
norepinephrine & epi
- secreted by, synthesized from, has
- catabolism: oxidation & methylation via (1.1)
- receptors (1.1), linked to + purpose
- epinephrine effect (2)
- norepinephrine: symp/parasym, region, effect + alpha 1 vs. 2 vs. beta
dopamine
- where/region, midway/what, released where
- metabolized by (2)
- receptors (2.3), linked to
NOREPINEPHRINE & EPINEPHRINE
- norepinephrine: inc HR; sympathetic; hypothalamus
- epinephrine: chonotropic (faster HR), inotropic (inc quality)
- secreted by adrenal medulla, synthesized from tyrosine (must be avoided by Htn), has catecholamines
catabolism
- oxidation via monoamine oxidase (MAO)
- methylation via catechol-o-methyltransferase (COMT)
receptors
- NE: alpha adrenergic; alpha 1 (bronchioles/dilate), alpha 2 (vascular/constrict), beta (heart/inc)
- E: beta adrenergic
- linked to g-protein (amplify signal)
DOPAMINE
- in autonomic ganglion, midway between NE&E (port between catecholamines), released in substantia nigra
- metabolized by MAO & COMT
- receptors: D1&5 (inc), D2-4 (dec), linked to G-protein
NT: 5-HT, Histamine
serotonin
- formed by (2) of (1), inactivated by (1)
- where/region (3)
- serotonergic: purpose (3), hypersensitive if
histamine
- released by (1), look like, formed from (1), where (2)
- effect (4)
SEROTONIN
- formed by hydroxylatio & decarboxylation of tryptophan
- inactivated by MAO
- in platelets, brainstem, GI
serotonergic
- induce sleep with melanin, temperature, control mood
- hypersensitive if pain/wound
HISTAMINE
- released by pos. hypothalamus, formed from histadine
- look like catecholamines
- in mast cell & cells in gastric mucosa
- effect: arousal, pituitary secretions, BP (inc), pain threshold
NT: Excitatory Amino Acids
glutamate - responsible for %, formed from, without this (2), if too much + stroke how, channel type
metabotropic receptor - linked with, effect
ionotropic - kainate & AMPA allow (1=1) & where (2), NMDA allow + need (1) + where (1)
glutamate
- 75% of excitatory transmission
- formed from krebs cycle
- without = incoordination, spatial learning
- stroke = blood loss = too much exocytosis of glutamate = kill neurons
- ligand gated ion channel
metabotropic receptor
- linked with g protein
- inc or dec cAMP
ionotropic receptor
kainate & AMPA
- allow Na & K
- in glial cells & neuron
NMDA
- allow Ca
- need glycine
- in neurons only
NT: Inhibitory Amino Acids
GABA
- formed from, E/I
- metabotropic vs. ionotropic receptor: GABA A vs. B, how (conductance)
- benzodiazepine, progesterone
substance p
- where/region
- mediate (1), cause (2), reflex
GABA
- formed from excess glutamate, inhibitory
- metabotropic: GABA B; inc K conductance
- ionotropic: GABA A, inc Cl conductance
- benzodiazepine & progesterone: rely on Cl
SUBSTANCE P
- in afferent of spinal cord
- mediate slow pain, cause redness & swelling
- axon reflex
NT: Extras
neuromodulator - where, purpose, messenger
extracellular cells - where, pathway for, cont with
neuromodulator
- in presynaptic cell; with NT
- enhance prolong inhibit effect
- has secondary messenger (G protein)
extracellular cells
- pathway for exchange between blood x cells & glial
- space between neuron & glial
- cont with CSF
