Blog #1

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

Voltage and ligand-gated channels. 

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

 

Voltage gated 

. Changes in membrane potential of the cell

. Transmits signal from cell body to nerve terminal

. Na+, k+ and Ca2+ channels 

Ligand-gated channels 

. Binding of ligand or neurotransmitter to ion channel 

. Ionotropic receptors

. GABA – a, nicotinic, choline, glutamate, serotonin receptors 

• Compare ionotropic and metabotropic receptors.

Ionotropic receptor is opening of ion channels  and metabotropic is the metabolic change that causes the channels to open allow binding 

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

Ionotropic receptors 

GABA – A : inhibits postsynaptic potential

Nicotinic : activates postsynaptic potential 

Glutamate : activates post synaptic potential 

Serotonin : activates postsynaptic potential 

Metabotropic 

G protein coupled receptors which works by 2 transduction systems which is the adenylyl cyclase system and phospholipase c.

In adenylyl cyclase system B1, 2 and dopamine 1 receptors which are positively bound results in change of ATP to cyclic Amp  and D2, alpha 2 and serotonin A and B as well as muscarinic are negatively bound will inhibit the effect. No second messenger is formed

Phospholipase c system works via stimulation of Alpha 1, serotonin 2, muscurinic and histamine 1 receptors thus stimulate PIP2 to form IP3 AND DAG 

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

EPSP means the excitatory of post synaptic potential by depolarization of ion channels e. g sodium and calcium channels 

IPSP means inhibitory of post synaptic potential by hyperpolarizing the ion channels e. g. Chloride 

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

Calcium ions trigger the release of neurotransmitter from synaptic vesicles into the synaptic cleft