Sign‐trackers have elevated myo‐inositol in the nucleus accumbens and ventral hippocampus following Pavlovian conditioned approach. Issue 6 (19th January 2016)

• Record Type: Journal Article
• Authors: Fitzpatrick, Christopher J.; Perrine, Shane A.; Ghoddoussi, Farhad; Galloway, Matthew P.; Morrow, Jonathan D.
• Is Part Of: Journal of neurochemistry. Volume 136:Issue 6(2016)
• Page Start: 1196
• Page End: 1203
• Publication Date: 2016-01-19
• Subjects: myo‐inositol -- nucleus accumbens -- Pavlovian conditioned approach -- proton‐magnetic resonance spectroscopy -- sign‐tracking -- ventral hippocampus; Neurochemistry -- Periodicals; 616.8042
• DOI: 10.1111/jnc.13524
• Languages: English
• ISSNs: 0022-3042

Abstract

Abstract: Pavlovian conditioned approach (PCA) is a behavioral procedure that can be used to assess individual differences in the addiction vulnerability of drug‐naïve rats and identify addiction vulnerability factors. Using proton magnetic resonance spectroscopy ( 1 H‐MRS) ex vivo, we simultaneously analyzed concentrations of multiple neurochemicals throughout the mesocorticolimbic system 2 weeks after PCA training in order to identify potential vulnerability factors to addiction in drug‐naïve rats for future investigations. Levels of myo ‐inositol (Ins), a 1 H‐MRS‐detectable marker of glial activity/proliferation, were increased in the nucleus accumbens (NAc) and ventral hippocampus, but not dorsal hippocampus or medial prefrontal cortex, of sign‐trackers compared to goal‐trackers or intermediate responders. In addition, Ins levels positively correlated with PCA behavior in the NAc and ventral hippocampus. Because the sign‐tracker phenotype is associated with increased drug‐seeking behavior, these results observed in drug‐naïve rats suggest that alterations in glial activity/proliferation within these regions may represent an addiction vulnerability factor. Sign‐tracking rats preferentially approach reward cues during Pavlovian conditioning, while goal‐trackers instead approach the location of impending reward. Sign‐trackers are also more prone to cue‐induced drug‐seeking behavior. We used magnetic resonance spectroscopy to show that myo‐inositol levels are higher in the ventral hippocampus and nucleus accumbens of sign‐trackers relative to goal‐trackers. Thus, elevated myo‐inositol may be a vulnerability factor for addiction. Abstract : Sign‐tracking rats preferentially approach reward cues during Pavlovian conditioning, while goal‐trackers instead approach the location of impending reward. Sign‐trackers are also more prone to cue‐induced drug‐seeking behavior. We used magnetic resonance spectroscopy to show that myo‐inositol levels are higher in the ventral hippocampus and nucleus accumbens of sign‐trackers relative to goal‐trackers. Thus, elevated myo‐inositol may be a vulnerability factor for addiction.