2. Do you remember??? Synapse Small empty space between 2 neurons Between the synaptic knob and dendrite

3. Overview Impulses must cross synapse to reach next neuron Uses chemicals Neurotransmitters Stored in vesicles within synaptic knobs

4. In Synaptic Knob Impulse reaches synaptic knob Synaptic vesicles move toward pre-synaptic membrane (on synaptic knob) Fuse with membrane using exocytosis

5. In Synapse Neurotransmitters Released from synaptic vesicles into synapse Diffuse across synapse Toward dendrite of adjacent neuron

7. Adjacent Neuron Neurotransmitters bind to a receptor site on post –synaptic membrane (on dendrite) Sodium channels open Impulse continues down neuron NOTE: A stronger stimulus causes impulses to arrive faster so more neuron transmitters are released

9. Back in Synapse Unused neurotransmitter must be removed from synapse Either: Re-enters synaptic knob Removed by enzyme