Sodium channel Potassium Channel Calcium Channel SNAP/SNARE proteins Dopamine Receptor toxin • Transports sodium ions • Transports potassium • Voltage-gated calcium • Present in the vesicle and • A G protein coupled receptor into the cell, depolarizing ions out of the cell, channels are activated neuronal membranes on post synaptic neuron when an action potential, the membrane, initiating repolarizing the • The in ux of calcium ions • Triggers reaction in cell based moves calcium ions into an action potential membrane triggers conformational on G protein coupled the cell • Tetrodotoxin (from • Scorpion toxins and changes enabling vesicle to receptor • Calcium is necessary for puersh) blocks the tarantula toxins block fusion with neuron membrane, • Dopamine binds to transport of sodium ions, the transport of potassium vesicular fusion required for releasing neurotransmitters Sodium/Potassium ATP the receptor, and thus ions, thus inhibiting action neurotransmitter release into synapse Pump triggering a response inhibiting potential • Inhibited by the cone within the cell, toxin • Active transport of an action • Some potassium snail toxin depending sodium and potassium to potential channels are not gated on the G re-establish gradient (leaky), but are open, toxin protein allowing potassium ions Ca+ ion • 3 sodium ions are coupled to K+ ion pumped out of the cell in Na+ ion to ow in the direction of receptor the concentration exchange for 2 potassium toxin gradient ions

Complex Synapse (NMDA and AMPA Receptor)

35 Action Potential

Repolarization 0 *Na+ Channels Closed *K+ Channels Open -35 Threshold (-50mV)

-70 Depolarization * Na+ Channels Open Membrane Potential (mV) Potential Membrane * K+ Channels Closed -105 PreSynaptic Time Neuron

Neuronal Synapse

Synaptic Cleft

PreSynaptic Neuron PostSynaptic Neuron 4 transporter transporter dopamine ed through • Recycl receptor on postsynaptic dopamine receptor • Bindsto messenger a chemical • Neurotransmitter, Dopamine 4 Ca passage ofNa channel allowing the cation• Nonselective and glycine (orD-serine) activated by glutamate • Ionotropic rec receptor • N-meth NMDA Receptor 2+ PostSynaptic yl-D-aspartate yl-D-aspartate Neuron + , K eptor + and Ca passage ofNa channel allowing the cati• Nonselective on activated receptor • Ionotropic glutamate propionic acidreceptor 5-methyl-4-isoxazole- •α-amino AMPA Receptor 2+ -3-hydroxy- + , K + and (cAMP) monophosphate adenosine to cyclic triphosphate (ATP) adenosine conversion of • Catalyzes the enzyme • membrane bound Adenylyl Cyclase receptor of theNMDA phosphorylation includes cellular functions • Oneofitsmany activated by cAMP e • Enzym Protein KinaseA receptor (antagonist) oftheNMDA activity • Bindsto andblocksthe (angel dust) • Phenc PCP “date rape” drugs • Oneofthe allosteric site channel andat an binding bothintheopen NMDA receptor by • Appears to inhibitthe Ketamine yclidine Neurotransmitters messengers - chemical receptor each ofthefour subunitsoftheAMPA the NMDA receptor andmay bindto • Bindsto two fo theGloN2subunitsof Glutamate (Glutamic Acid) the NMDA receptor • Bindsto two fo subunitsof theGloNl Glycine theNMDA receptor • Bindsto two fo subunitsof theGloNl D-serine

Complex Synapse (NMDA and AMPA R eceptor)