title: Regulation of netrin-1 receptors by amphetamine in the adult brain.
abstract: Netrin-1 is a guidance cue molecule fundamental to the organization of neuronal connectivity during development. Netrin-1 and its receptors, deleted in colorectal cancer (DCC) and UNC-5 homologues (UNC-5), continue to be expressed in the adult brain, although neither their function nor the kinds of events that activate their expression are known. Two lines of evidence suggest a role for netrin-1 in amphetamine-induced dopamine plasticity in the adult. First, DCC is highly expressed by adult dopamine neurons. Second, adult mice with reduced DCC levels do not develop amphetamine-induced behavioral sensitization. To explore the role of netrin-1 in amphetamine-induced plasticity, we examined the effects of sensitizing treatment regimens of amphetamine on DCC and/or UNC-5 protein expression in the adult rat. These treatments produced striking and enduring increases in DCC and UNC-5 expression in the cell body, but not terminal regions, of the mesocorticolimbic dopamine system. Notably, neuroadaptations in the cell body region of mesocorticolimbic dopamine neurons underlie the development of sensitization to the effects of amphetamine. Furthermore, these localized amphetamine-induced changes were prevented by co-treatment with an N-methyl-d-aspartate receptor antagonist, a treatment known to block the development of amphetamine-induced sensitization of behavioral activation, dopamine release and motivated behavior. Using immunohistochemistry, we showed that both DCC and UNC-5 receptors are highly expressed by adult mesocorticolimbic dopamine neurons. These results provide the first evidence that repeated exposure to a stimulant drug such as amphetamine affects netrin-1 receptor expression in the adult brain. Taken together, our findings suggest that changes in netrin-1 receptor expression may play a role in the lasting effects of exposure to amphetamine and other stimulant drugs.
authors.affiliation: Douglas Mental Health University Institute, Department of Psychiatry, McGill University, 6875 LaSalle Boulevard, Montreal, Quebec, Canada H4H 1R3.
authors.forename: L
authors.initials: L
authors.lastname: Yetnikoff
authors.forename: C
authors.initials: C
authors.lastname: Labelle-Dumais
authors.forename: C
authors.initials: C
authors.lastname: Flores
mesh_terms: D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D000075389:DCC Receptor; D004347:Drug Interactions; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009414:Nerve Growth Factors / Q000378:metabolism; D000075386:Netrin Receptors; D000075388:Netrin-1; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D000697:Central Nervous System Stimulants; D000075389:DCC Receptor; C501912:Dcc protein, rat; D018691:Excitatory Amino Acid Antagonists; D009414:Nerve Growth Factors; D000075386:Netrin Receptors; C000617353:Ntn1 protein, mouse; C000617354:Ntn1 protein, rat; D010879:Piperazines; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; C494222:UNC-5 protein, rat; D000075388:Netrin-1; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid; D000661:Amphetamine; D014446:Tyrosine 3-Monooxygenase