neuropharmacology (week 10-12) Flashcards
two types of neurotransmitter receptors
ion channels (act like a gate for ions. When neurotransmitter binds to it, it opens up and allows certain ions to flow in, usually resulting in an action potential), and g-protein coupled (when a neurotransmitter binds, it turns GDP into GTP, which energises a second messenger inside the cell which binds to another receptor in the cell)
what is receptor specificity
neurotransmitters and their receptors bind like a lock and key. Their physical makeups fit together, and the receptors are highly specific, meaning only certain transmitters can activate certain receptors
neurotransmitters vs neuromodulators
A neurotransmitter strictly from synapses which diffuses across a cleft to effect one or two postsynaptic neurons, a muscle cell, or other effector cell, and is ither excitatory or inhibitory. Neuromodulators effect groups of neurons or effector cells with the correct receptors. Must not be from a synapse, and usually works with secondary modulators, and can provide longer effects, often changing the receptivity of neurons.
how can neuromodulators alter synapse functioning
can affect the presynaptic neuron by impacting neurotransmitter release, can affect the postsynaptic neuron by altering neurotransmitter function (firing pattern or excitability), or changes neural function or structure, impacting synaptic plasticity
where are neuromodulators made and how do they go around the brain
they are found deep in the brain, in some nucleus, and are transported through various long neurons
where are neurotransmitters made and how do they transport
neurotransmitters are synthesised in the cell body of the neuron, and then they are slowly transported through the axons to the synapse, however, release is fast, because they sit in the synapse ready.
how do drugs work on receptors
drugs can mimic neurotransmitters by being similarly shaped, meaning that their either antagonise (prohibit binding of neurotranmitters resulting in no stimulation) or agonise (overstimulate) the receptors, resulting in the effect felt by the user. Drugs can affect all stages of neurotransmitters.
what is the cycle of neurotransmitters
synthesis, release from synaptic vesicles, binds to receptors, +/- influence on postsynaptic neuron, broken down by enzymes, reuptake of transmitter, formation and storage in synaptic vesicles. Drugs can effect all stages.
glutamate and GABA overview
both true neurotransmitters, released by presynaptic neuron, directly effecting the likelihood of neurons firing.
glutamate synthesis
it is synthesised from glutamine, which is released from neighbouring cells. Note, glutamate can be turned into GABA and GABA can be turned into glutamate.
glutamate receptors
4 major types, 3 ion channels (NMDA receptor, AMPA receptor, Kainate receptor).
NMDA receptor information (drugs)
complex and only works if glycine is bound and magnesium is not. Alcohol is the most common antagonist, and also agonises GABA (inhibitory). PCP and ketamine also antagonise this receptor, causing dissociative hallucination.
what is GABA
it is an inhibitory neurotransmitter which reduces the likelihood that neurons fire for their non-preferred stimulus. They do this by increasing the selectivity, not determining what signals the glutamate chooses
GABA Synthesis
Glutamate can be turned into GABA and GABA can be turned into glutamate.
types of seizures
gereralised (most brain areas), partial (specific brain regions, can ble split into simple (change of consciousness, but no loss of consciousness), and complex (loss of consciousness)).
seizures and genetics
mostly genes involved in seizures are to do with incorrect ion channels. Most causes of seisures though, are due to abnormal brain tissue
