title: Midbrain dopamine neurons associated with reward processing innervate the neurogenic subventricular zone.
abstract: Coordinated regulation of the adult neurogenic subventricular zone (SVZ) is accomplished by a myriad of intrinsic and extrinsic factors. The neurotransmitter dopamine is one regulatory molecule implicated in SVZ function. Nigrostriatal and ventral tegmental area (VTA) midbrain dopamine neurons innervate regions adjacent to the SVZ, and dopamine synapses are found on SVZ cells. Cell division within the SVZ is decreased in humans with Parkinson's disease and in animal models of Parkinson's disease following exposure to toxins that selectively remove nigrostriatal neurons, suggesting that dopamine is critical for SVZ function and nigrostriatal neurons are the main suppliers of SVZ dopamine. However, when we examined the aphakia mouse, which is deficient in nigrostriatal neurons, we found no detrimental effect to SVZ proliferation or organization. Instead, dopamine innervation of the SVZ tracked to neurons at the ventrolateral boundary of the VTA. This same dopaminergic neuron population also innervated the SVZ of control mice. Characterization of these neurons revealed expression of proteins indicative of VTA neurons. Furthermore, exposure to the neurotoxin MPTP depleted neurons in the ventrolateral VTA and resulted in decreased SVZ proliferation. Together, these results reveal that dopamine signaling in the SVZ originates from a population of midbrain neurons more typically associated with motivational and reward processing.
authors.affiliation: Department of Physiology and Neurobiology, Center for Regenerative Biology, University of Connecticut, Storrs, Connecticut 06269, USA.
authors.forename: Jessica B
authors.initials: JB
authors.lastname: Lennington
authors.forename: Sara
authors.initials: S
authors.lastname: Pope
authors.forename: Anna E
authors.initials: AE
authors.lastname: Goodheart
authors.forename: Linda
authors.initials: L
authors.lastname: Drozdowicz
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Daniels
authors.forename: John D
authors.initials: JD
authors.lastname: Salamone
authors.forename: Joanne C
authors.initials: JC
authors.lastname: Conover
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D000818:Animals; D004298:Dopamine / Q000235:genetics / Q000502:physiology*; D020547:Lateral Ventricles / Q000033:anatomy & histology*; D008297:Male; D008636:Mesencephalon / Q000033:anatomy & histology* / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D056347:Neuroanatomical Tract-Tracing Techniques / Q000379:methods; D055495:Neurogenesis / Q000187:drug effects / Q000502:physiology*; D056325:Neuronal Tract-Tracers / Q000378:metabolism; D009474:Neurons; D012201:Reward; D017557:Ventral Tegmental Area / Q000187:drug effects
chemical_list: D056325:Neuronal Tract-Tracers; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D004298:Dopamine