neuropharmacology 1 Flashcards
pharmacology
- the study of drug impacted changes in mood sensation and behavior
signalling in the brain: neuron
- at rest the neuron has a negative charge, an action potential is triggered when the charge becomes sufficiently positive
- signal received by dendrites and travels down the axon where the signal is sent to dendrites on the next axon
receptors
- neurons have a cell ‘membrane’ that acts like a wall preventing things from entering or leaving the neurons
- the cell wall has two layers with the fatty inside of each layer sticking together
- because of the fatty inside layer, fluids and other chemicals like neurotransmitters are unable to pass through
- receptors located on the outside of the cell membrane allow the released neurotransmitters to influence the post synaptic neurons
two types of receptors
- Ion channels
- G-protein coupled
receptor specifity
- each receptor can generally only be activated by one neurotransmitter
- they also have a very specific function, when a transmitter binds to the receptor this will trigger the same event every time
Ion channels
- act like a ‘gate’ for ions
- when a neurotransmitter binds to a receptor outside the neuron, this causes the gate to open and ions (pos and neg) will flow through
- channels are normally selective and only allow one or a few types of ions to pass through when they are open
G protein-coupled receptor
- G-protein receptors work through second messages
- when the NT bings to the receptor it activates a ‘second’ messanger system, that can either open a channel or cause other things to charge within the cell
neurotransmission
a chemical substance released from a neuron at an anatomically specialized junction, which diffuses across a narrow cleft to affect one or sometimes two postsynaptic neurons, a muscle cell or effector cell
- excitatory or inhibitory
neuromodulator
- a chemical substance released from a neuron in the central nervous system, or in the periphery, that affects groups of neurons, or effector cells that have the appropriate receptors. it may not be released at synaptic sites, it often acts through second messengers and can produce long-lasting effects
- describes slower processes that alter subsequent responsiveness of neurons
chem cocktail in the brain
- ‘currency’= excitatory, inhibitory
‘government’=modulatory: dopamine, noradrenaline, serotonin
neuromodulation (pt.2)
- presynaptic: alters neurotransmitter release
postsynaptic: alters neurotransmitter action - neuromodulation may cause changes in neural function or structure
action at the receptor
- drugs act by ‘mimicking’ natural neurotransmitters or modulators
- can act as agonists- activating the receptor
- or antagonists: blocking the receptor and preventing the natural compound from activating it.
cycle of neurotransmitters
- Synthesis
- Release from synaptic vessels’
3.Binds to receptors - Pos or neg influence on post synaptic neuron
- Broken down by enzymes
- Reuptake of transmitter
- Formation and storage in synaptic vessels.
- Release from synaptic vessels’
synthesis interruption
- NT function can be altered by increasing or decreasing synthesis of the neurotransmitter
transport interruption (MDMA example)
MDMA mimics serotonin so it flows into the presynaptic membrane, and prevents the serotonin from being packaged in vesicles, it gets pumped out of the cell and floods the cleft. It’s different from anti-depressants - which has a different effect on serotonin.
