The Institute for Biochemical and Psychological Study of Individual Differences is an interdisciplinary institute that analyzes the structures and signals of the major adaptive emotional systems. We focus on human individual differences in the systems that control the seeking of reward opportunities, the avoidance of dangers, risk-taking, risk analyses, and an individual’s capacity to build realistic cognitive models of external reality.
The settings, structures and signaling in the adaptive emotional systems differ from individual to individual. Broad patterns emerge in which some individuals, for example, are highly responsive to signals of new opportunities and potential rewards, but others fail to see those possibilities. Some individuals readily detect danger and threat, but others go too far, sensing danger when none exists. Some individuals are oblivious to clues of impending danger. These enduring patterns emerge in psychological studies as personality individual differences. Personality individual differences are conceptualized as the enduring parameters of briefly acting dynamic emotion systems.
The Institute works to understand the dynamic modulation of genetic and other biochemical features of these emotion systems. We are currently investigating the effects of threat signals in people with known psychological variations in the personality traits of Negative-Emotionality, and Disconstraint/Sensation Seeking and known biochemical variations in serotonergic and catecholamine systems, cortisol and corticotropic releasing hormone receptors and other hypothalamic-pituitary-adrenal axis signals.
Faculty & Staff
Allan R. Harkness, Department of Psychology
William T. Potter, Department of Chemistry
John L. McNulty, Department of Psychology
Robert Sheaff, Department of Chemistry
COMT is an enzyme that helps degrade catecholamines such as dopamine, epinephrine, and norepinephrine. It is also involved in degrading estrogen. Within a population the DNA for the COMT gene can vary due to Single Nucleotide Polymorphisms. A SNP is when a single base in the DNA changes. In the case of COMT the base Guanine changes to an Adenine. This causes one of the Valine amino acids to change to Methionine. This change causes the normally high activity enzyme to become less active.
COMT works with Monoamine Oxidase, another enzyme, to break down dopamine. The first step is the polymerase chain reaction. The DNA for the COMT gene is amplified using Polymerase Chain Reaction (PCR). This process amplifies only the specific gene enough times for the fragments to be separated and seen.
Each of the three steps are dependent on temperature, and repeated about 30 times. Each cycle doubles the amount of DNA. After the DNA is amplified many times, gel electrophoresis is used to separate the fragments based on their length and view the results. The shorter DNA pieces will travel farther across the gel. The bands indicate what the person’s genotype is.
Serotonin is a neurotransmitter involved in mood regulation. The serotonin transporter known as SLC6A4 recaptures synaptic serotonin back into the pre-synaptic neuron.
The gene that codes for the transporter has two important polymorphisms. These polymorphisms cause the gene to be either short or long. The short gene has lower transcriptional activity and has been linked to PTSD and other anxiety disorders.
The DNA is amplified using Polymerase Chain Reaction as described on the COMT page. The only major difference is in the primers used. For more SLC6A4 information:
The institute also conducts research in the following areas:
Brain Derived Neurotrophic Factor (BDNF)
Exhaled Breath Condensate (EBC)
Metal concentration in saliva