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Effects of isoflurane anesthesia and intravenous morphine self‐administration on regional glucose metabolism ([ 18 F] FDG ‐ PET ) of male Sprague‐Dawley rats
Author(s) -
Park Thomas Y.,
Nishida Kevin S.,
Wilson Colin M.,
Jaiswal Shalini,
Scott Jessica,
Hoy Andrew R.,
Selwyn Reed G.,
Dardzinski Bernard J.,
Choi Kwang H.
Publication year - 2017
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/ejn.13542
Subject(s) - isoflurane , anesthesia , morphine , thalamus , saline , basal ganglia , medicine , self administration , chemistry , endocrinology , central nervous system , radiology
Although certain drugs of abuse are known to disrupt brain glucose metabolism ( BG luM), the effects of opiates on BG luM are not well characterized. Moreover, preclinical positron emission tomography ( PET ) studies anesthetize animals during the scan, which limits clinical applications. We investigated the effects of (i) isoflurane anesthesia and (ii) intravenous morphine self‐administration ( MSA ) on BG luM in rats. Jugular vein cannulated adult male Sprague‐Dawley rats self‐administered either saline ( SSA ) or morphine (0.5 mg/kg/infusion, 4 h/day for 12 days). All animals were scanned twice with [ 18 F]‐fluoro‐deoxy‐glucose ( FDG )‐ PET / CT at a baseline and at 2‐day withdrawal from self‐administration. After the IV injection of FDG , one batch of animals ( n = 14) was anesthetized with isoflurane and the other batch ( n = 16) was kept awake during the FDG uptake (45 min). After FDG uptake, all animals were anesthetized in order to perform a PET / CT scan (30 min). Isoflurane anesthesia, as compared to the awake condition, reduced BG luM in the olfactory, cortex, thalamus, and basal ganglia, while increasing BG luM in the midbrain, hypothalamus, hippocampus, and cerebellum. Morphine self‐administered animals exhibited withdrawal signs (piloerection and increased defecation), drug seeking, and locomotor stimulation to morphine (0.5 mg/kg) during the 2 day withdrawal. The BG luM in the striatum was increased in the MSA group as compared to the SSA group; this effect was observed only in the isoflurane anesthesia, not the awake condition. These findings suggest that the choice of the FDG uptake condition may be important in preclinical PET studies and increased BG luM in the striatum may be associated with opiate seeking in withdrawal.