Serotonin 1A receptor availability in patients with schizophrenia and schizo-affective disorder: a positron emission tomography imaging study with [11C]WAY 100635.
BACKGROUND
Postmortem and positron emission tomography (PET) studies have reported several alterations in serotonin 1A receptor (5-HT(1A)) binding parameters in patients with schizophrenia. This study examines 5-HT(1A) availability in vivo in individuals with schizophrenia and schizo-affective disorder.


METHODS
Twenty-two medication-free individuals with schizophrenia or schizo-affective disorder and 18 healthy subjects underwent PET scans with [(11)C]WAY 100635. Regional distribution volumes (V(T), in milliliters per gram) were derived using a two-tissue compartment kinetic model. Outcome measures for 5-HT(1A) availability included binding potential (BP) and the specific to nonspecific equilibrium partition coefficient (V(3)''). Eleven brain regions with high density of 5-HT(1A) were included in the analysis.


RESULTS
No significant differences were observed in regional BP or V(3)'' between patients and controls. No significant relationships were observed between regional 5-HT(1A) availability and symptom severity.


CONCLUSIONS
The postmortem literature reports increased 5-HT(1A) binding in the prefrontal cortex in schizophrenia. This study did not detect differences in 5-HT(1A) binding. Whereas in two recently published PET studies, one reports increased binding in the temporal lobe while the other reports decreased binding in the amygdala. These inconsistencies suggest that the alterations demonstrated in postmortem studies cannot be reliably detected at the resolution achieved with PET. This raises the question as to whether major changes in the level of expression of the 5-HT(1A) receptor play a role in the pathophysiology of schizophrenia.
Frankle
W Gordon
WG
Departments of Psychiatry and Radiology, Western Psychiatric Institute and Clinic, University of Pittsburgh, Pittsburgh, PA 15213, USA. franklewg@upmc.edu
Lombardo
Ilise
I
Kegeles
Lawrence S
LS
Slifstein
Mark
M
Martin
John H
JH
Huang
Yiyun
Y
Hwang
Dah-Ren
DR
Reich
Elisa
E
Cangiano
Claudine
C
Gil
Roberto
R
Laruelle
Marc
M
Abi-Dargham
Anissa
A
D000328:Adult; D000679:Amygdala / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002250:Carbon Radioisotopes; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism; D006801:Humans; D008297:Male; D010879:Piperazines / Q000378:metabolism; D049268:Positron-Emission Tomography; D017397:Prefrontal Cortex / Q000378:metabolism; D011618:Psychotic Disorders / Q000378:metabolism*; D011725:Pyridines / Q000378:metabolism; D011869:Radioligand Assay / Q000379:methods; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012559:Schizophrenia / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000378:metabolism; D013702:Temporal Lobe / Q000378:metabolism
D002250:Carbon Radioisotopes; D010879:Piperazines; D011725:Pyridines; D012702:Serotonin Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide