1.

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

2.

• Voltage-gated ion channels only allow specific ions to pass through them while ligand-gated ion channels are non-specific and thus can open for many kinds of ions to pass though although a specific ligand has to bind to it in order for the channel to open. 
• Voltage-gated ion channels are sensitive to a change in membrane potential and will only open when there's a change on voltage. Whereas ligand-gated channels open when a ligand binds to them and are weakly or not at all sensitive to a change in membrane potential. 
• Voltage-gated ion channels are concentrated on the axons of nerve cells and include sodium channels for action potentials. Ligand-gated ion channels, however, are found on cell bodies and on both presynaptic and postsynaptic sides of the synaptic cleft.

3. Ionotropic                                                                          Metabotropic

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The binding to of a neurotransmitter to this receptor            Binding to these receptors does not directly 

causes an opening of ion channels causing an                    cause an opening of the channels. 

intracellular effect.                                                        

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These receptors are on neuronal surfaces and                    After a neurotransmitter binds to the G-protein

do not form second messengers.                                         coupled receptor, a second messenger is 

                                                                                              formed and causes the intracellular effect.

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Activation results in a very short opening of channels         Due to the involvement of a second messenger,

thus they're responsible for transmission.                            the effects of metabotropic receptors last much 

                                                                                              than those of ionotropic receptors.

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4. 

• Ionotropic receptors are: GABA_A, Nicotinic receptors, Excitatory Amino Acids (NMDA, AMPA and Kainate) and 5-HT₃ receptors. 
• There are two transduction systems that are innervated by metabotropic receptors and relay on second messengers, namely: the adenylyl cyclase system and the phospholipase C system. 

When neurotransmitters are positively bound to β₁₊₂ and D₁ receptors, ATP is converted to cAMP by adenylyl cyclase then cAMP is further converted to AMP by Phosphodiesterase. When they are negatively bound to D₂, α₂, 5-HT_1A+B and M₂ receptors, the formation of a second messenger is inhibited.

When neurotransmitters are bound to α₁, 5-HT₂, M₁ and H₁, Phosphoinositol diphosphate is converted to both Inositol triphosphate and Diacylglycerol by phospholipase C. 

5.

• An excitatory postsynaptic potential (EPSP) is a depolarizing membrane change that occurs when the excitatory pathway is stimulated. For example, when acetyl choline binds to nicotinic receptors to open Sodium channels. 
• An inhibitory postsynaptic potential (IPSP) is a hyperpolarizing membrane change that occurs when the inhibitory pathway is stimulated. For example when GABA_A binds to GABA receptors to open Chloride channels. 

6. An action potential opens Calcium channels (voltage sensitive) and calcium flows into the terminal. The increase in its concentration allows vessicles holding neurotransmitters to use with the presynaptic membrane therefore releasing the neurotransmitter into the synaptic cleft. The neurotransmitter binds to receptors therefore briefly changing the postsynaptic membrane's ion permeability. Without the calcium, the neurotransmitter would not be release and the entire process would not take place.