Final answer:
Stimulus is encoded through the ratio or comparative response across different cells, influenced by the rate of action potentials and the number of receptors activated. Cells commit to specific responses after integrating signals from various receptors, ensuring multiple conditions are satisfied.
Step-by-step explanation:
Stimulus is coded through the ratio of response across multiple cells by various mechanisms in the nervous system. The intensity of a stimulus can be encoded by the rate of action potentials and by the number of receptors activated. For instance, an intense stimulus generates a rapid train of action potentials and activates more receptors compared to a less intense stimulus. Sensory information is integrated as soon as it's received in the central nervous system (CNS), and further processing occurs to form a complete response to external cues.
Different cell types exhibit varied responses due to different protein expressions, and signal integration can occur when pathways from two or more cell-surface receptors converge to activate a cell's response. This ensures that a cell only commits to a specific response once multiple external requirements are met. Additionally, in some research, optically activated devices have been used to manipulate the expression of different proteins in neurons, which demonstrates the control and variability in cellular responses to stimuli.