Characteristics of NTs Flashcards
Norepi is released from
the locus ceruleus of midbrain
Norepi is released from which system ?
SNS
Norepi binds to what receptors
alpha or beta
Norepi release is enhanced by
amphetamines
Reuptake of norepi is blocked by
TCA (tricyclics), Cocaine
Reserpine has what effect on Norepi? leads to?
Reserpine decreases Norepi levels –> depression
Norepi is metabolized by
MAO and COMT
Metabolites of Norepi are:
- 3,4-Dihydroxymandelic acic (DOMA)
- Normethanephrine
- 3-methoxy-4-hydroxyphenyglycol (MOPEG)
- Vanillylmandelic acid (VMA)
In phenochromocytoma, what is excreted?
increased VMA excretion in urine
ACh is mainly what kind of NT?
Excitatory
-inhibitory on heart
ACh is secreted by:
motor neuron at NMJ
pre-ganglionic fibers of SNS and PNS
post-ganglionic fibers of PNS and some of SNS
this prolongs the effect of acetylcholine
organophosphate
nerve gas
*acts as AChE blocker –> prolonging effects of ACh
Treatment for organophosphate toxicity?
Atropine
-blocks muscarinic receptors
Release of ACh is inhibited by
botulinum toxin
- muscle paralysis
ACh receptors are blocked by
Curare
-muscle paralysis
this NT is decreased in Alzheimer’s disease
ACh
*give AChE blockers (Rivastigmine) to help
The ACh receptors are destroyed in
Myasthenia gravis
Epi is secreted, along with norepi from
adrenal medulla
Dopamine releases from
substantia nigra
dopamine inhibits
prolactin secretion
Dopamine is decreased in what disease process? why?
parkinson’s disease
-degeneration of dopamenergic neurons of substantia nigra
Dopamine is increased in what disease?
schizoprenia
Serotonin (or 5-HT) is formed from
tryptophan
Serotonin (5-HT) is produced by the
Raphe nuclei, dorsal horn of spinal cord
Serotonin is an ____ of pain pathways in the spinal cord
inhibitor
feeling good NT
Fluoxetine is
Prozac
*SSRI
SSRI’s inhibit
reuptake (recycling) of serotonin –> increasing serotonin levels
–antidepressant action
Histamine is present in the
hypothalamus
Histamine is formed from
histidine
Histamine is released by
mast cells
For increased stomach acid secretion, we’d give
H2 blockers
The most common excitatory NT is
Glutamate
“Go Glutamate Go”
This NT is known as the “stroke NT”
Glutamate
excites the cells to death in stroke
after a stroke, Glutamate increases intracellular
Na+ and Ca++
How many glutamate receptors are there?
four
- three subtypes
- including NMDA receptor
GABA-A receptors increase
Cl- conductance
The site of action of benzodiazepines (Valium) and barbiturates:
GABA A receptors
GABA-B receptors incease
K+ conductance
This is an inhibitory NT in the spinal cord, basal ganglia, cerebellum and cerebral cortex
GABA
This is an inhibitory NT mainly in the SPINAL cord
Glycine
Glycine is in the
spinal cord
Glycine increases
Cl- conductance
Tetanus toxin (clostridium tetanus) blocks
glycine –> tetanus
A short acting inhibitory NT
NO (nitric oxide)
NO acts in the
GIT
blood vessels
CNS
This NT acts via cGMP
Nitric Oxide (NO)
These are natural opiates
endorphins
Name types of endorphins
Dynorphin
Enkephalins
Endorphins inhibit release of
Substance P
no sub p to brain = no pain
This NT mediates pain sensation in PNS
Substance P
Somatostatin is what kind of NT hormone?
very inhibitory hormone
This NT has an anti-GH effect
Somatostatin
What NT also affects REM sleep
ACh
What NT’s affect Huntington’s
Ach and GABA
Acidosis on neuronal activity
depresses neuronal activity
-pH change from 7.4 to 7.0 will induce coma
Alkalosis effect on neuronal activity
increases neuronal excitability
-ph change from 7.4-8.0 will induce Seizures