Compare and contrast the activity of acetylcholine, dopamine, serotonin, and norepinephrine. If the statement applies to more than one, indicate which ones.
___________________________ curare interferes with the action of this neurotransmitter
___________________________ cocaine interferes with the reuptake of this neurotransmitter
___________________________ this neurotransmitter is degraded before it is taken back into the presynaptic cell
___________________________ this neurotransmitter functions in both the CNS and the PNS
___________________________ this neurotransmitter causes ion channels to open in postsynaptic cells
___________________________ this neurotransmitter is derived from tryptophan
___________________________ a G-protein in the postsynaptic membrane may be required for the action of this neurotransmitter
___________________________ these neurotransmitters are catecholamines
To compare and contrast the activity of acetylcholine, dopamine, serotonin, and norepinephrine, we can look at various characteristics and behaviors associated with these neurotransmitters. Let's go through each statement separately:
1. Curare interferes with the action of this neurotransmitter.
- Answer: Acetylcholine is the neurotransmitter that is affected by curare. Curare is a neuromuscular blocking agent that blocks the receptors for acetylcholine on muscle cells, leading to muscle paralysis.
2. Cocaine interferes with the reuptake of this neurotransmitter.
- Answer: Cocaine interferes with the reuptake of dopamine. It acts by inhibiting the dopamine transporter, preventing the reuptake of dopamine into the presynaptic cell. This leads to an increased concentration of dopamine in the synaptic cleft, resulting in prolonged and enhanced dopamine signaling.
3. This neurotransmitter is degraded before it is taken back into the presynaptic cell.
- Answer: Acetylcholine is the neurotransmitter that is degraded before reuptake. The enzyme acetylcholinesterase breaks down acetylcholine into choline and acetate, preventing its excessive accumulation in the synaptic cleft.
4. This neurotransmitter functions in both the CNS and the PNS.
- Answer: Acetylcholine functions in both the CNS and the PNS. In the CNS, it is involved in various cognitive functions, while in the PNS, it is responsible for transmitting nerve signals between motor neurons and skeletal muscles.
5. This neurotransmitter causes ion channels to open in postsynaptic cells.
- Answer: Acetylcholine is the neurotransmitter that causes ion channels to open in postsynaptic cells. When acetylcholine binds to nicotinic receptors on postsynaptic cells, it triggers the opening of ion channels, allowing the influx of positively charged ions, usually sodium (Na+), which generates an excitatory response.
6. This neurotransmitter is derived from tryptophan.
- Answer: Serotonin is the neurotransmitter derived from tryptophan. Tryptophan is an essential amino acid that gets converted into serotonin through a series of enzymatic reactions.
7. A G-protein in the postsynaptic membrane may be required for the action of this neurotransmitter.
- Answer: Dopamine, serotonin, and norepinephrine may require a G-protein in the postsynaptic membrane for their action. These neurotransmitters typically bind to G-protein coupled receptors (GPCRs) on postsynaptic cells, which initiates signaling cascades via G-proteins.
8. These neurotransmitters are catecholamines.
- Answer: Dopamine and norepinephrine are both catecholamines. These neurotransmitters are derived from the amino acid tyrosine and contain a catechol ring structure. Serotonin, however, is not a catecholamine.
By analyzing the characteristics and behaviors of these neurotransmitters, we can compare and contrast their activities in various contexts.