title: Vesicular glutamate transporter 2 and tyrosine hydroxylase are not co-localized in Syrian hamster nucleus accumbens afferents.
abstract: The nucleus accumbens (NAc) is an important brain region for motivation, reinforcement, and reward. Afferents to the NAc can be divided into two anatomically segregated neurochemical phenotypes: dopaminergic inputs, primarily from the midbrain ventral tegmental area (VTA) and glutamatergic inputs from several cortical and sub-cortical structures. A population of glutamatergic neurons exists within the VTA and evidence from rats and mice suggests that these VTA axons may co-release dopamine and glutamate into the NAc. Our laboratory has used sexual experience in Syrian hamsters as a model of experience-dependent plasticity within the NAc. Given that both dopamine and glutamate are involved in this plasticity, it is important to determine whether these neurotransmitters are co-expressed within the mesolimbic pathway of hamsters. We therefore used immunofluorescent staining to investigate the possible co-localization of tyrosine hydroxylase (TH), a dopaminergic marker, and vesicular glutamate transporter 2 (VGLUT2), a glutamatergic marker, within the mesolimbic pathway. PCR analyses identified VGLUT2 gene expression in the VTA. No co-localization of TH and VGLUT2 protein was detected in NAc fibers, nor was there a difference in immunolabeling between males and females. Further studies are needed to resolve this absence of anatomical co-localization of TH and VGLUT2 in hamster striatal afferents with reports of functional co-release in other rodents.
authors.affiliation: University of Minnesota, Department of Neuroscience, 6-145 Jackson Hall, 321 Church Street, Minneapolis, MN 55455, USA. lbeen@umn.edu
authors.forename: Laura E
authors.initials: LE
authors.lastname: Been
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Staffend
authors.forename: Avery
authors.initials: A
authors.lastname: Tucker
authors.forename: Robert L
authors.initials: RL
authors.lastname: Meisel
mesh_terms: D000818:Animals; D006224:Cricetinae; D005260:Female; D008297:Male; D008647:Mesocricetus; D009474:Neurons / Q000378:metabolism*; D009714:Nucleus Accumbens / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*; D050599:Vesicular Glutamate Transport Protein 2 / Q000378:metabolism*
chemical_list: D050599:Vesicular Glutamate Transport Protein 2; D014446:Tyrosine 3-Monooxygenase
keywords: Caudate putamen; Co-localization; Dopamine; Glutamate; Ventral tegmental area