1. SYNAPSES D. C. Mikulecky Professor of Physiology http://views.vcu.edu/~mikuleck/

2. TWO TYPES OF SYNAPSE ELECTRICAL CHEMICAL

3. ELECTRICAL GAP JUNCTION: PROVIDES PATH FOR IONS TO FLOW FROM ONE CELL TO ANOTHER CELL 1 CELL 2

4. CHEMICAL: THE SYNAPSE INCOMING NERVE POST SYNAPTIC NERVE SPACE

5. EVENTS IN CELLULAR COMMUNICATION INPUT SIGNAL (CHEMICAL,MECHANICAL, PHOTO, ELECTRICAL) RESPONSE (OUTPUT) SECRETION CONTRACTION/RELAXATION DIVISION PHAGOCYTOSIS RECEPTOR TRANSDUCER EFFECTOR ENZYMES,GENOME,CONTRACTILE FILAMENTS, SECRETORY GRANULES

6. HOW ARE WE WIRED?CONNECTIONS BETWEEN NERVE CELLS CELL BODY DENDRITES AXON HILLOCK AXON TERMINALS

7. THE NATURE OF CHEMICAL TRANSMISSION BETWEEN NERVES PRESYNAPTIC EVENTS POSTSYNAPTIC EVENTS IN THE SPACE

8. PRESYNAPTIC EVENTS THE ALL OR NONE ACTION POTENTIAL TRIGGERS THE RELEASE OF CHEMICAL TRANSMITTER

9. INCOMING ACTION POTENTIAL DEPOLARIZES TRIGGERS CALCIUM CHANNELS CALCIUM ENTERS THE CELL

10. THE SYNAPSE SYNAPTIC VESSICLES INCOMING ACTION POTENTIAL CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

11. THE SYNAPSE: INCOMING ACTION POTENTAL SYNAPTIC VESSICLES INCOMING ACTION POTENTIAL CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

12. CALCIUM INFLUX CAUSES VESSICLES TO BE RELEASED VESSICLES MIGRATE TO MEMBRANE EXOCYTOSIS NEUROTRANSMITTER ENTERS SPACE

13. THE SYNAPSE: CALCIUM CHANNELS OPEN SYNAPTIC VESSICLES INCOMING ACTION POTENTIAL CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

14. THE SYNAPSE: NEUROTRANSMITTER ENTERS SPACE SYNAPTIC VESSICLES CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

15. POST SYNAPTIC EVENTS IONOTROPIC (LIGAND GATED) CHANNELS VOLTAGE GATED CHANNELS ELECTROPHYSIOLOGICAL PRINCIPLES

16. IONOTROPIC CHANNELS BIND NEUROTRANSMITTER OPEN CHANNEL HYPER OR DE-POLARIZATION

17. THE SYNAPSE:NEUROTRANSMITTER BINDS TO POSTSYNAPTIC RECEPTOR SYNAPTIC VESSICLES CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

18. HOW ARE WE WIRED?CONNECTIONS BETWEEN NERVE CELLS CELL BODY DENDRITES AXON HILLOCK AXON TERMINALS

19. POSTSYNAPTIC POTENTIALS RESTING POTENTIAL IPSP EPSP TIME

20. SPATIAL SUMMATION TIME SIMULTANEOUS INPUT FROM TWO SYNAPSES: ABOVE THRESHOLD

21. SPATIAL SUMMATION TIME SIMULTANEOUS INPUT FROM TWO SYNAPSES: ABOVE THRESHOLD

22. TEMPORAL SUMMATION TIME TOO FAR APART IN TIME: NO SUMMATION

23. TEMPORAL SUMMATION TIME CLOSER IN TIME: SUMMATION BUT BELOW THRESHOLD THRESHOLD

24. THE GOLDMAN-HODGKIN-KATZ (GHK) EQUATION [Ko] +  [Nao] Vm = 60 LOG -------------------------- [Ki] +  [Nai]  IS THE RATIO OF SODIUM TO POTASSIUM PERMEABILITY

25. TEMPORAL SUMMATION TIME STILL CLOSER IN TIME: ABOVE THRESHOLD

26. EPSP-IPSP CANCELLATION

27. HOW EXCITATION OCCURS-THE ROLE OF DEPOLARIZATION AND HYPERPOLARIZATION SUMMATION CAN DEPOLARIZE THE CELL BEYOND THRESHOLD HYPERPOLARIZATION BLOCKS

29. NEURO TRANSMITTERS ACETYL CHOLINE DOPAMINE NOREPINEPHRINE EPINEPHRINE SEROTONIN HISTAMINE GLYCINE GLUTAMINE GAMMA- AMINOBUTYRIC ACID (GABA)

30. IN THE SPACE ENZYME “CHEWS UP” LIGAND MASS ACTION CAUSES LIGAND TO DISSOCIATE FROM RECEPTOR

31. THE SYNAPSE SYNAPTIC VESSICLES CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME

32. THE SYNAPSE SYNAPTIC VESSICLES CALCIUM CHANNEL ION CHANNEL RECEPTOR ENZYME