Neuropharmacology Flashcards
how many neurons in the brain?
100 billion
how many synapses in the cortex?
0.15 quadrillion
what are the two types of receptors?
ion channels and g protein coupled receptor
how do ion channels function? and what do they allow?
NT attaches to receptor which then opens the gate of the ion channel, and only allows selective ions to flow through, eg, calcium channel only allows calcium ions to flow through
how do g protein coupled receptors work?
NT binds to this receptor that activates second messenger system that can open a channel or cause other changes to take place in the cell, (eg, dna being transcribed and new proteins being made)
what is the main difference between a NT and neuromodulator
serving the function of being released at a anatomically specialised location to have localised and specific effect, while NM are sort of a bit more all over the place
can the same molecule act as both a NT and NM?
yes
in regards to NT and NM, what is the currency, and what is the gov/police?
NT’s are currency (excitatory or inhibitory)
NMs are more the police (serotonin, dopamine, noradrenaline etc)
which is excitatory, which is inhibitory out of glutmate and gaba?
glutamate = excitatory gaba = inhibitory
NMs alter what at the pre-synapse? they alter what at the post synapse?
pre: NT release
post: NT action (excitability/firing pattern)
for drugs to have an effect, what do they HAVE to do?
dock onto a receptor
how do drugs have an effect on receptors?
they mimick natural NTs or NMs
drugs acting as agonists do what?
activate the receptor like the natural compound does
drugs acting as antagonists do what?
block the receptor and prevent the natural compound from activating the receptor
is the process from synthesis to NT action slow or fast ?
the synthesis is thought to be slow, but the NT action is very fast as it is sitting, waiting for release
what are the most common NTs in the CNS?
Glutamate and GABA
what makes ‘true’ NT?
directly affecting the likelihood of the post synaptic Neuron firing
what is released by ALL excitatory neurons?
Glutamate
estimated that over half of all brain synapses release what?
glutamate
what actually is glutamate?
glutamic acid
is glutamate used as a NT in its raw form?
yes
is glutamate an amino acid?
yes
why does glutamate as an amino acid still need to be synthesised in the brain despite it already being a NT?
because this amino acid cannot pass through the blood barrier
what is glutamate synthesised from?
glutamine
T or false, excitatory connections are not point to point.
false
how many glutamate receptors are there? what are they all called?
specify which are ion channels (ionotropic) and which are g protein coupled (metabotropic)
4 ion channels NMDA receptor AMPA receptor Kainate Receptor
g protein coupled
metabotropic glutamate
how many different binding sites are on the NMDA receptor?
6.
what is glycine?
an amino acid
if the NMDA receptor is open, what channel does it open, allowing what to flow through it?
calcium channel
Ca2+
the NMDA receptor only works if what molecule is attached?
and if what is not bound to the inside?
glycine
magnesium cannot be bound to the inside
alcohol is what an an NMDA receptor? resulting in?
antagonist, resulting in the NMDA receptor being blocked
reduction on glutamate as a result of alcohol is believed to contribute to what?
general sedative effects and memory effects
while alcohol is an NMDA antagonist, what is it also?
what does this lead to?
it is also an agonist for GABA
further brain inhibition
which two drugs in addition to alcohol affect NMDA receptors? are they antagonists or agonists?
Phencyclidine (PCP) and ketamine
both ketamine and PCP cause what?
dissociative hallucinations
what are dissociative hallucinations?
people feel disconnected, but do not have “sensory overload” like other hallucinogens do
can ketamine kill someone?
no, it does not harm the actual body, but there is a risk of suicidal behaviour
what is psychosis? what are the symptoms of it?
not a diagnosis, but a cluster of symptoms
- delusions
- hallucinations
- depression
- anxiety
- suicidal thoughts or actions
- disorganised speech
what is the percentage of population experiencing psychosis?
around 3%
is there a link between glutamate and psychosis?
some have suggested a link but there is much more to it
what does NMDA-R encephalitis involve?
inflammation of the brain caused by autoimmune response to NMDA receptors
NMDA receptor is crucial for what?
learning, memory, perception and synaptic plasticity in general
what have large schizophrenia studies identified?
likely that the NMDA receptor gene is likely relevant to dev of schizophrenia
what is the primary inhibitory NT?
GABA
what does gaba stand for?
gamma - amino - butyric - acid
what does GABA do?
decreases likelihood of post synaptic neuron firing
what is the importance of GABA and inhibitory NTs
keeps the brain under wraps, otherwise there would be constant firing which is bad (seizures)
How does gaba help neurons fire?
it plays important role in the selectivity of neurons firing
what is GABA produced from
glutamic acid
how many types of gaba receptors are there? what are they called and what type of receptor are they?
2
GABA a receptor (ion channels)
GABA b receptor (g protein coupled)
how many people in Aus experience seizure disorders?
400,000
what is a generalised seizure?
a seizure that is widespread and involves most of the brain
what is a partial seizure?
seizure that is restricted to small part of the brain
what is a complex seizure?
a seizure where the individual loses consciousness
what is a simple seizure?
a seizure where changes in consciousness can happen, but no loss in consciousness takes place
the majority of genes that have been found to be involved in seizures are linked to what?
ion channels, thus influencing the level of positive or negative charge in the brain that drive action potentials
what are the two main nuclei responsible for the synthesis and release of dopamine?
substantia nigra (SN) ventral tegmental area (VTA)
T or F?
the substantia nigra and the ventral tegemental area can release both dopamine and another NT?
false
what is tryrosine? where is it found? what is it/what does it do?
amino acid
found in food
it is the building block of dopamine
what is tryrosine hydroxylase?
it is a synthesis enzyme for tryrosine
what does Tryrosine Hydroxylase turn tryrosine in to?
DOPA
what synthesis enzyme turns DOPE into dopamine?
Amino acid decarboxylase
if dopamine is synthesised by dopamine beta-hydroxylase, what does it become?
noradrenaline
what are the three variations of elements in the dopamine synthesis?
Tryrosine
DOPA
dopamine
What is L-DOPA ? what does it do?
a synthetic version of DOPA that can be synthesised to Dopeamine
what is the cause of parkinson’s?
death of dopamine cells in substantia nigra
what are symptoms of parkinson’s?
motor tremor, cog impairments, dementia and overall reduced exec. function
what are some potential side effects of receiving treatment for parkinson’s?
impulsively, gambling, hyper-sexuality
what is the use of reward prediction error
provides us with explanation of how dopamine works
what does dopamine actually code?
not the reward itself, but rather the expectation or unexpectedness of the reward
what are “real” rewards
food and sex
what are “symbolic” rewards?
money