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Individual differences in response to novelty predict prefrontal cortex dopamine transporter function and cell surface expression
Author(s) -
Zhu Jun,
Bardo Michael T.,
Bruntz Ronald C.,
Stairs Dustin J.,
Dwoskin Linda P.
Publication year - 2007
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/j.1460-9568.2007.05690.x
Subject(s) - novelty , prefrontal cortex , nicotine , dopamine , psychology , dopamine transporter , neuroscience , novelty seeking , endocrinology , medicine , chemistry , biology , cognition , dopaminergic , social psychology , personality , temperament
Previous research has shown that individual differences in response to novelty predict self‐administration and the locomotor response to psychostimulant drugs of abuse. The aim of the present study was to determine if individual differences in response to novelty based on inescapable or free‐choice novelty tests predict dopamine transporter (DAT) function and trafficking as well as nicotine‐induced modulation of DAT. Results show that the maximal velocity ( V max ) of [ 3 H]dopamine uptake into prefrontal cortex (PFC) synaptosomes correlated negatively with the locomotor response to inescapable novelty. In contrast, V max correlated positively with novelty place preference in the free‐choice novelty test. The divergent correlations between DAT and the two behavioral phenotypes suggest a differential contribution of DAT in these phenotypes, which are known not to be isomorphic. Furthermore, rats categorized as high responders to inescapable novelty had lower V max values, which were accompanied by less DAT expression at the cell surface in PFC compared with low responders, suggesting that inherent individual differences in DAT cellular localization may underlie the differential response to novelty. Compared with the saline control, nicotine increased V max and cell surface DAT immunoreactivity in PFC from high responders but not from low responders. Similarly, nicotine increased V max and cell surface DAT in PFC in rats classified as low in novelty place preference but not in rats classified as high in novelty place preference. Thus, despite the different behavioral phenotypes, the pharmacological effect of nicotine to increase DAT function and cell surface expression was apparent, such that rats with inherently lower DAT function show a greater sensitivity to the neurochemical effect of nicotine.