Question

Acetylcholine is a neurotransmitter that can have a wide range of effects on the post-synaptic cell based on the cell receptor/cell signaling machinery. In some cases, the release of acetylcholine by the pre-synaptic neuron will cause an inhibitory post-synaptic potential. In other cases, acetylcholine will cause an excitatory post-synaptic potential. Clearly explain how these two effects are possible from the release of a single neurotransmitter.

Answer 1

Acetylcholine can cause both excitatory and inhibitory responses in post-synaptic cells, depending on the type of receptors present. Nicotinic receptors typically lead to excitation, while muscarinic receptors can cause either excitation or inhibition.

Step-by-step explanation:

Acetylcholine (ACh), when released from a pre-synaptic neuron, has the ability to create either an excitatory or an inhibitory response in the post-synaptic cell. The effect of ACh is mediated by the type of receptors present on the post-synaptic membrane. When ACh binds to nicotinic receptors, it typically causes an influx of Na+, leading to depolarization and an excitatory postsynaptic potential (EPSP). This makes the post-synaptic neuron more likely to fire an action potential. Conversely, binding to muscarinic receptors can lead to hyperpolarization or depolarization, depending on the receptor subtype, which can cause an inhibitory post-synaptic potential (IPSP) or an EPSP, respectively.