According to the Hyper-Responsive LC model of depression, the event best correlated in time with a decrease in symptoms of depression (e.g., after 2 weeks of drug therapy) by tricyclic antidepressants is:

A. blockade of reuptake of neurotransmitter(s)

B. receptor down-regulation

C. receptor up-regulation

D. inhibition of monoamine oxidase (MAO)

C. Receptor up-regulation

Step-by-step explanation

Up regulation is used by cells to increase their sensitivity to a specific hormone. Up regulation occurs when a cell produces more receptors, the cell decreases its degradation of receptors or by activating already present recpetors. Cells typically up regulate when the concentration of a hormone is very little.

Tricyclic antidepressants (TCAs) are a class of antidepressant medications that share a similar chemical structure and biological effects. Scientists believe that patients with depression may have an imbalance in neurotransmitters, chemicals that nerves make and use to communicate with other nerves.