• Which types of ion channels are found on the nerve cell membranes?

• Voltage-gated ion channels
• Ligand-gated ion channels

• Name 3 differences between voltage-gated and ligand-gated ion channels.

• Voltage-gated ion channels:

- Controlled by changes in the membrane potential of the cell.

- Transmits signal from cell body to the nerve terminal.

- Na⁺, K⁺ and Ca²⁺ channels.

• Ligand-gated ion channels:

- Binding of a ligand (neurotransmitter) to ion channel.

- Ionotropic receptor

• Compare ionotropic and metabotropic receptors.

IONOTROPIC RECEPTOR:	METABOTROPIC RECEPTOR:
Transmembrane ion channels that open or close in response to binding of a chemical messenger.	7-Transmembrane G-protein coupled receptor
Ion channels	2nd messengers
Open quickly and remain open for only a few milliseconds	Effects last longer (minutes)
Effect occurs only in immediate region of the receptor	Effect is widespread throughout the cell

• Classify the CNS receptors into ionotropic and metabotropic and know the transduction mechanism of each receptor.

• Ionotropic receptors – GABA_A , Nicotinic, EAA and 5-HT₃
• Metabotropic receptors – Adenylyl cyclase system and Phospholipase C system

Phospholipase C – Conversion of PIP₂ to DAG and IP_3,

• Explain the difference between an EPSP and an IPSP and give examples of each.

• EPSP – excitatory postsynaptic potential. The EPSP causes a neuron to be more likely to generate an action potential. Eg. The binding of a acetylcholine to a nicotinic receptor.
• IPSP – inhibitory postsynaptic potential. This is a type of postsynaptic potential that causes a postsynaptic neuron to be less likely to generate an action potential. Eg. GABA receptor located on postsynaptic membranes are stimulated, they then cause an opening of the chloride channels. This results in hyperpolarization.

• What is the role of calcium in the development of a synaptic potential?

• Neurotransmitter is released from synaptic vesicles into the synaptic cleft.