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Faculty Name

Karen Stevens, PhD

Last Name (not displayed)

Stevens

Status

Inactive

Degree

PhD

Title

Associate Professor of Psychiatry, University of Colorado School of Medicine Research Pharmacologist, Denver VAMC

Department

​Psychiatry

Description of Research

​The research uses rodent models of a sensory inhibition deficit commonly observed in schizophrenia to investigate underlying mechanisms and to develop new drug therapies. Both mouse and rat models are employed. Deficient sensory inhibition is the inability to adequately “filter” incoming sensory stimuli to keep the brain from responding to repetitive information. A failure of this inhibitory system can lead to sensory overload or “flooding”. This flooding interferes with attention, learning and memory and may contribute to psychosis. Our primary research uses a mouse model which has both phenotypic and genotypic similarities to schizophrenia. Specifically, the strain of inbred mouse (DBA/2) spontaneous shows deficient sensory inhibition using a paradigm in which 2 identical auditory stimuli are delivered 0.5 sec apart and recording the electrophysiological response to both stimuli. Normal sensory inhibition shows a reduced response to the second stimulus. A deficiency, such as these mice and schizophrenia patients have, shows a similar magnitude response to both stimuli. Additionally, schizophrenia patients and DBA/2 mice both have reduced numbers of a specific nicotinic receptor subtype, the alpha 7, on hippocampal interneurons, and both show polymorphisms in the gene coding for this receptor. Current work centers on a developmental intervention which can permanently improve sensory inhibition in the mouse model as well as development of new drugs to ameliorate the deficit. In addition, a chronic recording model using awake and behaving rats is being used to further investigate the mechanisms of deficient sensory inhibition. These studies use intracerebroventricular injections of antisense oligonucleotides specific for the mRNA of selected neurotransmitter receptors to alter the numbers of the receptors in order to study the role of these receptors in normal and deficient sensory inhibition.

Methodology

Biomarkers: Human and Animal Models

Clinical and special developmental populations

Anxiety; Depression; Pregnancy; Schizophrenia

Location

RC1-North, Room 8105

Contact email

Karen.Stevens@ucdenver.edu

Faculty/Lab Website

 

Post-doctoral trainees

Kristin Wildeboar, PhD
Kalynn Schulz, PhD (co-sponsor)

Research Topic

rodent models of underlying mechanisms of sensory inhibition deficit in schizophrenia

Mentor since

4/12/2005

Institution

​University of Colorado School of Medicine

Contact Number

303-724-4423

Faculty Picture

Karen Stevens, PhD

DPRG Website

Stevens DPRG webpage

Department website

Stevens Department webpage

Attachments

Created at 8/15/2012 2:56 PM by Greco-Sanders, Linda
Last modified at 5/7/2013 12:35 PM by Miller, Michael