BIOL 3P43 Lecture Notes - Lecture 99: Patch Clamp, Metabotropic Receptor

Botulinus toxin causes paralysis. It binds to presynaptic sitesat the motor end plate (neuromuscular junction) and prevents theexocytotic release of transmitter from vesicles. Predict theconsequences (increase, decrease, no change & explain why) ofblocking the release of acetylcholine at the neuromuscular junctionon the following: 1. Presynaptic resting potential 2. Presynapticaction potential amplitude 3. Presynaptic Ca2+ influx 4.Presynaptic transmitter release 5. Postsynaptic resting potential6. Postsynaptic end plate potential 7. Postsynaptic actionpotential amplitude 8. Postsynaptic action potential frequency 9.Muscle contractile strength

4. Explain the nature of chemical synaptic transmission.

a. Illustrate the structure of a cholinergic synapse. Describe the process of signal transmission at a cholinergic synapse. What is the role of each of the following: calcium, acetylcholinesterase, and acetylcholine receptor. How does activity of the acetylcholine receptor depend on its structure? What is an EPSP, and how can it trigger an action potential in the postsynaptic cell?

b. Define IPSP. What role do inhibitory synapses play in action potential formation?