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Author Richardson, Kimberlei A. ♦ Aston-Jones, Gary
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Ventral Tegmental Area Differentially Activated ♦ Morphine Preference ♦ Positive Correlation ♦ Ventral Tegmental Area ♦ Protracted Abstinence ♦ Several Function ♦ V Nondependent ♦ Nonreward Area ♦ Cpp Test Day ♦ Post-dependent Animal ♦ Orexin Projection ♦ Increased Fo ♦ Male Sprague Dawley Rat ♦ Caudal Vta-projecting Lh Orexin Cell ♦ Vta-projecting Orexin Neuron Fo ♦ Locus Ceruleus ♦ Orexin Neuron ♦ Morphine Cpp ♦ Place Preference ♦ Protracted Morphine Abstinence ♦ Post Dependence ♦ Unilateral Injection ♦ Orexin Cell ♦ Pellet Removal ♦ Significant Target ♦ Cpp Score ♦ Possible Site ♦ Orexin Action ♦ Lh Orexin Neuron ♦ Vta Exhibit Fo Activation ♦ Cpp Conditioning ♦ Rostral Vta-projecting ♦ Lateral Hypothalamus ♦ Drug Preference ♦ Placebo Pellet ♦ Functional Topography ♦ Retrograde Tracer ♦ Reward Processing ♦ Lh Orexin Cell ♦ Lc-projecting Orexin Cell ♦ Nondependent Animal
Abstract Orexin (or hypocretin) is synthesized exclusively in dorsomedial, perifornical, and lateral hypothalamus (LH). These neurons are implicated in several functions, including reward processing. We examined the ventral tegmental area (VTA) as a possible site of orexin action for drug preference during protracted morphine abstinence, and studied functional topography of orexin projections to VTA. Male Sprague Dawley rats were used to investigate whether orexin cells that project to VTA exhibit Fos activation with morphine conditioned place preference (CPP), and whether these cells exhibit increased Fos with morphine CPP during protracted abstinence. Unilateral injections of a retrograde tracer (WGA-Au, 350–400 nl) were made into the VTA or a nonreward area, locus ceruleus, and morphine or placebo pellets were implanted for 14 d. Approximately 2 weeks after pellet removal (post dependence), CPP conditioning and testing were conducted. Triple labeling for WGA-Au, Fos, and orexin revealed that the percentage of VTA-projecting orexin neurons Fos activated on the CPP test day significantly increased in post-dependent (vs nondependent) rats, and was exclusive to LH orexin neurons (not dorsomedial or perifornical). Post-dependent animals showed a positive correlation between CPP scores and percentages of Fosactivated, caudal VTA-projecting LH orexin cells. Unlike afferents to caudal VTA, percentages of rostral VTA-projecting, LH orexin cells that were Fos activated showed a positive correlation with CPP only in nondependent animals. Fos in LC-projecting orexin cells was not correlated with CPP in any group. These results indicate that VTA is a heterogeneous and functionally significant target of orexin neurons
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Publisher Date 2011-01-01