Brain Blood Flow Changes Elicited by Oxytocin in Volunteers With and Without Schizophrenia
Summary
The purpose of this study is to assess how oxytocin delivered intranasally changes regional brain blood flow measured by positron emission tomography (PET) in conjunction with oxygen-15 labeled water in persons with schizophrenia. The objective is to better our understanding of oxytocin's role in the modulation of social judgment in schizophrenia and provide more information as to potential uses of oxytocin or a similar drug analog in treating certain features of schizophrenia and other neuropsychiatric disorders.
Description
Schizophrenia is a severely debilitating psychiatric disorder that afflicts approximately 1% of the population (American Psychiatric Association, 1994) and is a serious public health problem. The specific mechanism of schizophrenia remains unknown. Affective responsivity and adaptive social behaviors are fundamental impairments in people with schizophrenia. These features have a detrimental impact on function in many areas of daily life. Unfortunately, the brain mechanisms that underlie these problems are still not understood. This study will use positron emission tomography (PET) and regional cerebral blood flow (rCBF) measures to ascertain the timing (1.5 hour period) of OT action on absolute regional brain activity in schizophrenia (SZ) and healthy control (HC) subjects. Particular focus will be on the amygdala, ventral striatum, anterior hippocampus and hypothalamus (neural regions involved in affliative behavior). Subjects will be studied with intranasally administered oxytocin and placebo while at rest and while making judgments about emotional faces. This approach will tell us to what extent the amygdala and limbic system's physiological response to oxytocin is predictive of a subject's behavioral sensitivity to this neuropeptide. The elucidation of this information may have a significant impact on predicting functional outcome and novel drug treatments in schizophrenia.
Functional magnetic resonance imaging (MRI) studies show that oxytocin modulates the amygdala's response during social and emotional decisions. When administered intranasally, OT may be beneficial for the treatment of negative symptoms in schizophrenia by enhancing a person's affiliative behavior and diminishing distrust. It is not, however, known to what extent intranasal oxytocin modifies regional neurotransmission and human brain metabolism. There are at present no studies in animals or humans specifically examining the time course action of OT on whole brain activity.
Study Design
Control: Placebo Control, Intervention Model: Parallel Assignment, Masking: Single Blind (Subject), Primary Purpose: Basic Science
Conditions
Schizophrenia
Intervention
Oxytocin
Location
Maryland Psychiatric Research Center
Catonsville
Maryland
United States
21228
Status
Not yet recruiting
Source
University of Maryland
Results (where available)
Links
- Source: http://clinicaltrials.gov/show/NCT01123317
- Information obtained from ClinicalTrials.gov on July 15, 2010
Medical and Biotech [MESH] Definitions
Receptors, Oxytocin
Cell surface proteins that bind oxytocin with high affinity and trigger intracellular changes which influence the behavior of cells. Oxytocin receptors in the uterus and the mammary glands mediate the hormone's stimulation of contraction and milk ejection. The presence of oxytocin and oxytocin receptors in neurons of the brain probably reflects an additional role as a neurotransmitter.
Oxytocin
A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on SMOOTH MUSCLE CELLS, such as causing UTERINE CONTRACTIONS and MILK EJECTION.
Neurophysins
Carrier proteins for OXYTOCIN and VASOPRESSIN. They are polypeptides of about 10-kDa, synthesized in the HYPOTHALAMUS. Neurophysin I is associated with oxytocin and neurophysin II is associated with vasopressin in their respective precursors and during transportation down the axons to the neurohypophysis (PITUITARY GLAND, POSTERIOR).
Schizophrenia, Paranoid
A chronic form of schizophrenia characterized primarily by the presence of persecutory or grandiose delusions, often associated with hallucination.
Schizophrenia, Catatonic
A type of schizophrenia characterized by abnormality of motor behavior which may involve particular forms of stupor, rigidity, excitement or inappropriate posture.
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