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Synapses - Coggle Diagram

- - - - the first antidepressants drugs were MAO inhibitors - increasing the brain's supply of serotonin, dopamine and norep.
  - - - effects can differ: the receptor may open a channel - exerting an ionotropic effect OR it may produce a slower but longer effect - a metabotropic effect
        
        Ionotropic effect - the neurotransmitter twists the receptor just enough to open its central channel, so certain ions can pass through --> these are transmitter-gated or ligand-gated channels
        
        ligand: a chemical that binds to something
        
        Ionotropic effects begin quickly and they decay with a half-life of about 5 ms
        
        most of the brain's excitatory ionotropic synapses use the neurotransmitter glutamate
        
        acetylcholine - another transmitter, in most cases excitatory
        
        most of the inhibitory ionotropic synapses use the neurotransmitter GABA (Gamma-aminobutyric acid)
        
        opens chloride gates, enabling chloride ions with their negative charge to cross the membrane into the cell more rapidly than usual
        
        another common inhibitory transmitter is glycine
        
        Metabotropic effects - start slowly but last longer, last up to a few seconds. metabotropic synapses use many nruotransmitters (dopamine, norepinephrine, serotonine, GABA, glutamate, etc.)
        
        Ionotropic synapse has effects localized to one point on the membrane, whereas a metabotropic synapse influences activity in much or all of the cell and over a longer time
        
        for vision and hearing, the brain needs rapid, up-to-date info (ionotropic)
        taste, smell and pain - metabotropic, the exact timing isn't important
        
        the neurotransmitter attaches to a metabotropic receptor - the other side of that receptor is attached to a G protein (energy storing molecule) --> the receptor bends, and the G protein detaches, so it is free to take its energy elsewhere - result: a second messenger, that carries the info around the cell
- - - - this circuit from sensory neuron to muscle response is called a reflex arc
  - - - IPSP occurs when synaptic input selectively opens the gates for potassium ions to leave the cell (positive charge) or for chloride ions to enter the cell (carrying a negative charge)
  - - - the neuron that delivers transmission is the presynaptic neuron, and the one that receives it is the postsynaptic neuron
- - - - posterior: oxytocin and vasopressing (antidiuretic hormones)
- - - - any transmitter molecules that the transporters do not take will instead break down by an enzyme called COMT (breakdwon washes away, in blood and urine)
  - - - cannabinoids bind to this, or 2-AG receptors indicating "the cell got your message, stop sending it" - the presynaptic cell stops sending, and this way marijuana decrease both excitatory and inhibitory messages (glutamate, GABA) - usually the result is decreased anxiety