Related Experiment Video
Updated: May 23, 2026
08:49
Rapid In Situ Hybridization using Oligonucleotide Probes on Paraformaldehyde-prefixed Brain of Rats with Serotonin Syndrome
Published on: September 23, 2015
The effect of the serotonin transporter polymorphism (5-HTTLPR) on amygdala function: a meta-analysis.
S E Murphy1, R Norbury, B R Godlewska
1Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, UK. susannah.murphy@psych.ox.ac.uk
Molecular Psychiatry
|April 11, 2012
Summary
The serotonin-transporter-linked polymorphic region (5-HTTLPR) shows a small, statistically significant link to amygdala activity. However, this association is weaker than previously believed, with many studies lacking sufficient power.
Area of Science:
- Neurogenetics
- Psychiatric Genetics
- Molecular Psychiatry
Background:
- The 5-HTTLPR polymorphism is a candidate genetic risk factor for affective disorders.
- Previous studies suggest an association between 5-HTTLPR and amygdala reactivity, but evidence strength is uncertain.
Purpose of the Study:
- To synthesize existing data on the 5-HTTLPR polymorphism and amygdala activation.
- To ascertain the strength of evidence for this genetic association.
Main Methods:
- Meta-analysis of published and unpublished studies.
- Formal testing for publication bias.
- Exploration of study-level characteristics influencing effect size.
Main Results:
- A statistically significant but small effect of 5-HTTLPR on left and right amygdala activity was found.
- Considerable between-study heterogeneity was observed, not fully explained by study design or sample characteristics.
- Evidence of excess statistical significance in published studies suggests potential bias.
Conclusions:
- The association between 5-HTTLPR and amygdala activation is smaller than previously estimated.
- Many prior studies were underpowered to reliably detect the true effect size.
Related Concept Videos
01:11Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
01:28Human Genetics
Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
The complex relationship between genetics and psychology is observable through common biological components such...
01:21Drugs Affecting Neurotransmitter Release or Uptake
Certain drugs can affect how neurotransmitters called catecholamines, are released or taken back up in the adrenergic neuron. They can have different effects on the body's sympathetic transmission. Reserpine, a natural compound found in the Rauwolfia shrub, blocks a transporter called vesicular monoamine transporter (VMAT), which leads to a buildup of catecholamines in the cell and reduces sympathetic transmission. Another drug called guanethidine works in multiple ways, including blocking...
01:23Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Serotonin, a crucial neurotransmitter synthesized by enterochromaffin cells, plays a cardinal role in regulating gastrointestinal (GI) motility. With over 90% of the body's total serotonin in the GI tract, its influence on digestive processes is profound. Serotonin is swiftly released upon various stimuli, such as food boluses or certain drugs, triggering intrinsic sensory neurons in the myenteric plexus and extrinsic vagal and spinal sensory neurons. This leads to the activation of the...
01:16Role of Amygdala in Memory
The amygdala is a small, almond-shaped structure responsible for processing and storing memories, particularly those linked to emotions like fear and stress. It plays an essential role in the brain's response to emotionally significant events and often enhances memory formation by triggering stress hormone release. The amygdala is vital for encoding and retrieving memories associated with fear or stress, a process that is adaptive by helping organisms avoid dangerous situations.
One of the...
One of the...
01:16Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...