Question

. Identify the primary mechanism of action of tricyclic antidepressants _______.

a. potentiation of norepinephrine and serotonin activity by blocking their reuptake
b. increase concentrations of serotonin, norepinephrine, and dopamine by inhibition of the monoamine oxidase enzyme
c. selective blockade of serotonin reabsorption, helping to restore the brain's chemical balance
d. dopamine receptor blockade

Answer 1

Tricyclic antidepressants work by blocking the reuptake of norepinephrine and serotonin into the presynaptic neuron, leading to increased levels of these neurotransmitters in the synaptic cleft and prolonged interaction with postsynaptic receptors.

Step-by-step explanation:

The primary mechanism of action of tricyclic antidepressants is the potentiation of norepinephrine and serotonin activity by blocking their reuptake. These drugs, including compounds like imipramine and amitriptyline, function by inhibiting the reabsorption of these neurotransmitters into the presynaptic neuron, which results in an increased concentration of the neurotransmitters in the synaptic cleft. This allows for more prolonged interaction with the postsynaptic receptors, enhancing their mood-elevating effects, which is crucial in treating depression. Tricyclic antidepressants also differ from SSRIs, which selectively block serotonin reuptake, and from monoamine oxidase inhibitors (MAOIs) which increase neurotransmitters by inhibiting the enzyme that degrades them.