Serotonin depletion decreases serotonin transporter mRNA levels in rat brain

• Published in: Brain research Vol. 697; no. 1; pp. 251 - 253
• Main Authors: Linnet, Kristian, Koed, Karen, Wiborg, Ove, Gregersen, Niels
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 30-10-1995; Amsterdam Elsevier; New York, NY
• Subjects: Animals; Biochemistry and metabolism; Biological and medical sciences; Blotting, Northern; Carrier Proteins - genetics; Central nervous system; Fenclonine - analogs & derivatives; Fenclonine - pharmacology; Fundamental and applied biological sciences. Psychology; Gene Expression; Imipramine; Imipramine - pharmacology; Male; Membrane Glycoproteins - genetics; Membrane Transport Proteins; Mesencephalon - metabolism; Midbrain raphe; mRNA; Nerve Tissue Proteins; Raphe Nuclei - metabolism; Rats; Rats, Wistar; Reference Values; RNA, Messenger - metabolism; Serotonin - deficiency; Serotonin depletion; Serotonin Plasma Membrane Transport Proteins; Serotonin transporter; Time Factors; Vertebrates: nervous system and sense organs; Imipramine; Midbrain raphe; mRNA; Serotonin transporter; Serotonin depletion; Vertebrata; Mammalia; Messenger RNA; Rat; Serotonin; Rodentia; Central nervous system; Neurotransmitter; Gene expression; Carrier protein; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/0006-8993(95)00906-7

In order to study the impact of serotonin depletion on gene expression of the serotonin transporter (5-HT
t) we measured 5-HT
t mRNA levels by Northern blot in rats treated with
p-chlorophenylalanine methyl ester (PCPA) for 10 days. Six rats received PCPA i.p. only, and another 6 rats receiving 0.9% NaCl served as controls. An additional group of 6 rats received both PCPA i.p. and imipramine, 5 mg/kg/day by osmotic minipumps. 5-HT
t mRNA levels decreased to 81.1% (
P = 0.05) and 76.0% (
P = 0.05) of the control level for PCPA treated animals without and with concomitant imipramine treatment, respectively. The average level of the PCPA treated groups was 78.6% (
P = 0.03). The isolated effect of 21 days of imipramine treatment was a 5-HT
t mRNA level of 89.4%, which was not significantly different from the control level. In conclusion, 5_HT
t gene expression is suppressed in the serotonin depleted state. A decreased synaptic reuptake of 5-HT may be interpreted as a compensatory mechanism aiming at preserving adequate synaptic 5-HT levels in a generally deficient state.