Cells convey and process information through intricate networks of interacting molecules. These "computational devices of live cells" control a variety of crucial cellular functions, such as signal transduction and cell-cycle regulation. Here, we talk about how sensitive the networks are to changes in their biological characteristics. We suggest a method for basic signal transduction networks to adapt robustly. We demonstrate how this mechanism specifically pertains to bacterial chemotaxis. This is shown in a mathematical model that unifies the explanation of several facets of chemotaxis, including appropriate reactions to chemical gradients. Changes in serotonin turnover have received attention as one of the biological co-morbidities of depression for a number of years. Low serotonin levels in the brains of suicide victims are one source of evidence supporting the neurotransmitter's involvement in depressive illness. Low concentrations of its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were found in the Cerebral Fluid (CSF) of patients with depression.
