Final answer:
A cell's decreased sensitivity to subsequent stimuli can result from the removal of AMPA receptors due to low-frequency stimulation, hormone level-induced down-regulation of receptors, hyperpolarization via specific ion channels, or contact inhibition mechanisms.
Step-by-step explanation:
When a cell has decreased sensitivity to subsequent stimuli, several mechanisms can be in play. For example, following low-frequency stimulation, a different Ca2+ signaling cascade can occur leading to the removal of AMPA receptors from the neuronal membrane. This removal makes nerve cells less responsive to neurotransmitters like glutamate, affecting how the cell communicates.
Furthermore, the sensitivity of cells to hormones can also be regulated by the number of receptors. In a process called down-regulation, cellular sensitivity is reduced, thereby decreasing cellular activity due to a lower number of receptors in high hormone levels. The opposite, up-regulation, occurs when receptor numbers increase, making a cell more sensitive to a hormone.
Additionally, some stimuli can cause hyperpolarization of a cell, depending on which ion channels are activated. This change in membrane potential makes it more difficult for additional stimuli to initiate a response.
Lastly, physiological mechanisms like contact inhibition prevent overproliferation of cells when they come into contact with each other, ensuring cells don't divide unnecessarily, which can also be seen as a form of decreased sensitivity to growth stimuli.