Fig. 7
From: A tale of two transmitters: serotonin and histamine as in vivo biomarkers of chronic stress in mice
Pharmacologically targeting hippocampal histamine and serotonin concentrations to alleviate stress-induced changes in serotonin. A In the model, three representative mice population are considered: control mice administered the SSRI, ESCIT) (in blue), a serotonin elevating drug, chronic mild stress (CMS) mice given ESCIT (in gray) and CMS mice treated with ESCIT and histamine-synthesis blockers α-fluoromethylhistidine (FMH) (in purple). These representative mice population differ from one another based on their serotonin levels and treatment received. It must be noted that our model was studied at steady state. The time plotted here is just to show a more realistic comparison of our model predictions with the experiments conducted to test our observations. In the model ESCIT administration refers to a two-fold increase in τ5HT and 1.25-fold increase in τHA. Furthermore, FMH administration refers to a two-fold decrease in IHA. Here, τHA = 0.8 s−1, τ5HT = 0.8 s−1, α = 398 s−1, β = 0.0013 s−1, I5HT = 118.75 nMs−1 and IHA = 1.25*104 nMs−1 for healthy condition and IHA = 3.88*104 nMs−1 for the stressed condition. B In vivo data showing basal hippocampal serotonin in control mice given saline and then ESCIT (i.p., 10 mg kg−1, n = 7, in blue), CMS-treated mice given saline and then ESCIT (i.p., 0.2 mg kg−1, n = 8, in gray), and CMS-treated mice given saline and then ESCIT (i.p., 10 mg kg−1) and FMH (i.p., 20 mg kg−1, n = 5, in purple). C Modified histamine/serotonin schematic showing the influence of an SSRI on the system in control and chronic stress