Imaging of the Serotonin System: Radiotracers and Applications in Memory Disorders

Abstract Introduction Brain-derived neurotrophic factor (BDNF) has been implicated in the pro-neurogenic effect of selective serotonin reuptake inhibitors. In this study, we used Tph2 −/− mice lacking brain serotonin to dissect the interplay between BDNF and the serotonin system in mediating the effects of antidepressant pharmacotherapy on adult neurogenesis in the hippocampus. Methods Besides citalopram (CIT), we tested tianeptine (TIA), an antidepressant whose mechanism of action is not well understood. Specifically, we examined cell survival and endogenous concentrations of BDNF following daily injection of the drugs. Results Twenty-one days of CIT, but not of TIA, led to a significant increase in the survival of newly generated cells in the dentate gyrus of wild-type mice, without a significant effect on BDNF protein levels by either treatment. In Tph2 −/− mice, adult neurogenesis was consistently increased. Furthermore, Tph2 −/− mice showed increased BDNF protein levels, which were not affected by TIA but were significantly reduced by CIT. Discussion We conclude that the effects of CIT on adult neurogenesis are not explained by changes in BDNF protein concentrations in the hippocampus.

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A clinical trial with desglycinamide arginine vasopressin for the treatment of memory disorders in man

Progress in Neuro-Psychopharmacology and Biological Psychiatry ◽

10.1016/0278-5846(85)90091-0 ◽

1985 ◽

Vol 9 (3) ◽

pp. 273-284 ◽

Cited By ~ 14

Author(s):

Aagje Jennekens-Schinkel ◽

Axel R. Wintzen ◽

Jan B.K. Lanser

Keyword(s):

Clinical Trial ◽

Arginine Vasopressin ◽

Memory Disorders

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Serotonin transporter is not required for the development of severe pulmonary hypertension in the Sugen hypoxia rat model

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00127.2015 ◽

2015 ◽

Vol 309 (10) ◽

pp. L1164-L1173 ◽

Cited By ~ 10

Author(s):

Michiel Alexander de Raaf ◽

Yvet Kroeze ◽

Anthonieke Middelman ◽

Frances S. de Man ◽

Helma de Jong ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Right Ventricular ◽

Serotonin Transporter ◽

Rat Model ◽

Systolic Pressure ◽

Serum Levels ◽

Normal Function ◽

Ventricular Systolic Pressure ◽

Serotonin System ◽

Pulmonary Arterial

Increased serotonin serum levels have been proposed to play a key role in pulmonary arterial hypertension (PAH) by regulating vessel tone and vascular smooth muscle cell proliferation. An intact serotonin system, which critically depends on a normal function of the serotonin transporter (SERT), is required for the development of experimental pulmonary hypertension in rodents exposed to hypoxia or monocrotaline. While these animal models resemble human PAH only with respect to vascular media remodeling, we hypothesized that SERT is likewise required for the presence of lumen-obliterating intima remodeling, a hallmark of human PAH reproduced in the Sugen hypoxia (SuHx) rat model of severe angioproliferative pulmonary hypertension. Therefore, SERT wild-type (WT) and knockout (KO) rats were exposed to the SuHx protocol. SERT KO rats, while completely lacking SERT, were hemodynamically indistinguishable from WT rats. After exposure to SuHx, similar degrees of severe angioproliferative pulmonary hypertension and right ventricular hypertrophy developed in WT and KO rats (right ventricular systolic pressure 60 vs. 55 mmHg, intima thickness 38 vs. 30%, respectively). In conclusion, despite its implicated importance in PAH, SERT does not play an essential role in the pathogenesis of severe angioobliterative pulmonary hypertension in rats exposed to SuHx.

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