Central serotonin depletion affects rat brain areas differently: A qualitative and quantitative comparison between different treatment schemes

Serotonin Depletion Does not Modify the Short-Term Brain Hypometabolism and Hippocampal Neurodegeneration Induced by the Lithium–Pilocarpine Model of Status Epilepticus in Rats

“…Dose and duration of PCPA (125 mg/kg/day 9 7 days; from day -4 to day ?2) were chosen in order to achieve an intense brain 5-HT depletion during the SE and the acute phase of epileptogenesis. The expected depletion should be [90 % according to reports by Saadat et al (2005) and Kornum et al (2006). Although a 15-day PCPA treatment has been associated with a plethora of brain alterations, including reactive gliosis (Ramos et al 2000), neither neurodegeneration, astrogliosis nor modification of basal brain glucose consumption were detected in our study, pointing that the different length of PCPA treatment may account for this discrepancy.…”

“…PCPA, a specific inhibitor of tryptophan hydroxylase was administered once daily for 7 days (125 mg/kg, i.p., from day -4 to day ?2). This drug regimen was chosen based in the high degree of 5-HT depletion ([90 %) yielded by similar treatments (Saadat et al 2005;Kornum et al 2006). Thus, 150 mg/kg PCPA for just 2 days was reported to markedly reduce 5-HT tissue concentration in several rat brain regions (e.g., 93 % reduction was found in hippocampus).…”

Genetic variation in 5-hydroxytryptamine transporter expression causes adaptive changes in 5-HT4 receptor levels

“…The fact that no increases were observed after pCPA in other brain regions of 5-HTT +/ + mice may suggest that, under wild-type 5-HTT expression, longer and/or more severe 5-HT depletion (such as that observed in 5-HTT OE mice) is required to induce increased 5-HT 4 receptor binding in other brain regions. Supporting this, one study using a y95 % 5-HT depletion (Kornum et al 2006) found increased 5-HT 4 receptor binding in hypothalamus, in addition to hippocampus, but not in caudate putamen or globus pallidus (Licht et al 2009). Another study, using total brain 5-HT depletion for 3 wk (Compan et al 1996a) reported increased 5-HT 4 receptor binding in caudate putamen, globus pallidus and hippocampus (hypothalamus not examined).…”

Acute and chronic tryptophan depletion differentially regulate central 5-HT1A and 5-HT2A receptor binding in the rat

“…Tryptophan hydroxylase inhibitors and 5-HT releasers produce greater reductions in central 5-HT than TRP depletion, decreasing 5-HT to 5-30% of controls (Dewar et al 1992;Kornum et al 2006), suggesting that receptor changes produced by tryptophan depletion may be more subtle than those induced by pharmacological depletion.…”