Related Experiment Video
Updated: Jun 24, 2026

Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome
Published on: September 23, 2015
Allelic variation in the serotonin transporter promoter modulates cortical excitability
Berthold Langguth1, Philipp Sand, Roger Marek
1Department of Psychiatry, University of Regensburg, Universitaetsstrasse 84, Regensburg D-93053, Germany. Berthold.Langguth@medbo.de
Background:
Transcranial magnetic stimulation (TMS) is a noninvasive procedure that may be used to study individual differences in motor cortex excitability. Such differences are assumed to reflect serotonergic and other inputs to the motor cortex.
Methods:
Here we investigate the impact of a functional polymorphism in the promoter region of the 5-hydroxytryptamine transporter gene (5-HTTLPR) on measures of motor cortex excitability.
Results:
Sixty healthy subjects carrying one or two copies of the short 5-HTTLPR allele (s/s and s/l) showed a significant reduction in short intracortical inhibition (SICI, p = .012) and an increased cortical silent period (p = .042) compared with 60 age- and sex-matched individuals homozygous for the long allele (l/l). In contrast, motor threshold and intracortical facilitation did not differ significantly between groups.
Conclusions:
These results provide further evidence of a role for serotonergic transmission in the modulation of cortical excitability. Differential effects on the measures under study suggest a pattern of prioritization in bioamine regulation of cortical inhibition.
Related Concept Videos
Human Genetics
The complex relationship between genetics and psychology is observable through common biological components such...
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Excitatory and Inhibitory Effects of Neurotransmitters
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Antiepileptic Drugs: Modulators of Neurotransmitter Release Mediated by SV2A Protein
SV2A is a transmembrane glycoprotein located predominantly in the brain, modulating the release of neurotransmitters for neuronal communication. Both levetiracetam and brivaracetam exhibit a high affinity for...
Drugs Affecting Neurotransmitter Release or Uptake

