Neurotransmitters/channels/receptors Flashcards
What is glutamate the precursor to?
GABA
What is glutamate (the major excitatory neurotransmitter in the brain) thought to be very important in?
Learning and memory
What is the theory of excitotoxicity?
Excessive glutamate lead to excessive intracellular calcium and NO concentrations and cell death
See Raphe’s substantial dopy blue NEs
- Serotonin-Raphe
- Substantia nigra-dopamine
- Locus ceruleous- norepinephrine
Where are Noradrenergic neurons found primarily and what do they do?
Locus ceruleus, stimulation of the locus ceruleus increases anxiety and ablation of the locus ceruleus blocks anxiety response
7 transmembrane-domaine receptor requires what to open ion channels? What is on the outside and what is on the side?
- G protein
- NH2 outside and COOH intracellular
What type of receptor do NGF and BDNF use?
Tyrosine kinase receptor
Can hormones and steroids diffuse into a neuron and bind to cytoplasmic receptors whose effects carry to the nucleus and regulate gene expression?
yes
Is the channel in ligand-gated ion channel receptors built into the complex that binds the ligand?
Yes
Decreased levels of what in CSF have been linked to higher levels of aggression?
Serotonin (5-hydroxyindoleacetic acid)
In general what has been shown to promote aggression and what has seen to inhibit it?
Promote: dop
Inhibit: NE, serotonin, GABA
Where is acetylcholine made?
Nucleus basalis of Meynert
What are the six biogenic amine neurotransmitters?
- dopamine
- epinephrine
- norepinephrine
- histamine
- serotonin
- acetylcholine
What is the precursor for dopamine, NE, epinephrine?
tyrosine
What are the secondary messengers?
IP3(relase of intracellular calcium from ER), cGMP, Ca2+(excess CA is linked to production of NO and cell death through excociticity), cAMP, DAG, NO and CO
Glatamate receptors
AMPA, NMDA, Kainate
NE which receptros
Alpha 1, alpha2, beta receptors
serotonin which receptros
5HT
Gaba which receptors
GABA
Opiods receptor
mew
delta
buspirone
serotonin 1A agonist or partial agonist 2-3 weeks to be therapeutic max dose 60 - can increase levels of haldol - buspar levels are increased by nefazodone, erythromycin, itraconazole, grapefruit juice by inhibition of CYP3A4
Excitatory neurotransmitter open what type of channels and what happens
cation channels that depolarize the cell membrane and increase the likeihood of generating an action potential
WHen a neuron is at rest the sodium ions and chloride ions are more prevalent where ?
outside the cell
potassium on inside
when at rest neuron more negatively charged on the inside
3 sodium out and 2 potassium in
when reaches certain voltage sodium rushes in–>becomes more positive-depolarization then it shuts then potassium comes out –>hyperpolarization
- repolarization- sodium channels inactive
Neurotransmitters are synthesized in the presynaptic neuron, what are their synthesis and release mediated by?
Ca2+ influx
During an action potential the first ion channel to open is sodium then what channel opens?
Ca, allowing more positively charged ions to enter and contribute to the action potetential
- calcium ions critical to release of neurotransmitter
- activate opening of potassium ion channels that then put stop to action potential through hyperpolization of the membrane
Is the GABA receptor a chloride ion channel
yes
Diminished what plays a role in suicidal behavior?
low CSF 5-HIAA
Glycine
necessary adjunctive neurotransmitter at the NMDA receptor that binds with glutamate
- also an independent inhibitory neurotransmitter with its own receptors that open chloride ion channels
- mutations–>hyperekplexia-exggerated startle response
what is the rate limiting enzyme in dopamine synthesis
tyrosine hydroxylase
l-tyrosine to l-dopa
norepinephrine synthesis
dopamine b hydroxylase converts dopamine to norepinephrine
GABA receptor
when GABA receptor is occupied by an agonist there is a rapid influx of negatively charged chloride ions
GABA-A
alcohol, barbituates, benzos
GABA-B
- sodium oxybate (date rape_ used for cataplexy and narcolepsy)
- lioresal- antipasticity agent
what does NMDA receptor allow to pass through?
calcium, potassium, sodium
when does nmda receptor open
when it is bound by 2 glutamate and one glycine
- can be blocked by physiological concentrations of magnesium and bounded by PCP
basal forebrain is the location of the nucleus of basalis of meynert, what type of neruons are there?
cholinergic
- Alzheimers disease is a result of cholinergic neuronal demise predominantly in the nucleus basalis of Meynert
what is acetylcholine responsible for?
maintaining short term memory, attention, executive functiong, and novelty seeking which are mediated through the nucleus basalis of Meynert
- Alzheimers acetylcholine is depleted
H1 blockade
weight gain and sedation
Acetylcholine blockade
dry mouth, constipation, blurry vision, urinary retention, and cognitive dysfunction
a1 blcokade
orthostatic hypotension and drowsiness
