title: 6-Hydroxydopamine-Induced Dopamine Reductions in the Nucleus Accumbens, but not the Medial Prefrontal Cortex, Impair Cincinnati Water Maze Egocentric and Morris Water Maze Allocentric Navigation in Male Sprague-Dawley Rats.
abstract: The nucleus accumbens (Nacc) and medial prefrontal cortex (mPFC) receive dopaminergic innervation from the ventral tegmental area and are involved in learning. Male rats with 6-hydroxydopamine (6-OHDA)-induced dopaminergic and noradrenergic reductions in the Nacc or mPFC were tested for allocentric and egocentric learning to determine their role in these forms of neuroplasticity. mPFC dopaminergic and noradrenergic reductions did not result in changes to either type of learning or memory. Nacc dopaminergic and noradrenergic reductions resulted in allocentric learning and memory deficits in the Morris water maze (MWM) on acquisition, reversal, and probe trials. MWM cued performance was also affected, but straight-channel swim times and swim speed during hidden platform trials in the MWM were not affected. Nacc dopaminergic and noradrenergic reductions also impaired egocentric learning in the Cincinnati water maze (CWM). Nacc-lesioned animals tested in the CWM in an alternate path through the maze were not significantly affected. 6-OHDA injections in the Nacc resulted in 63 % dopamine and 62 % norepinephrine reductions in the Nacc and 23 % reductions in adjacent dorsal striatum. 6-OHDA injections in the mPFC resulted in 88 % reductions in dopamine and 59 % reductions in norepinephrine. Hence, Nacc dopamine and/or norepinephrine play a role in egocentric and allocentric learning and memory, while mPFC dopamine and norepinephrine do not.
authors.affiliation: Division of Neurology (MLC 7044), Cincinnati Children's Research Foundation and Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.
authors.forename: Amanda A
authors.initials: AA
authors.lastname: Braun
authors.affiliation: Division of Neurology (MLC 7044), Cincinnati Children's Research Foundation and Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.|Department of Nutrition, University of Wisconsin, Madison, WI, USA.
authors.forename: Robyn M
authors.initials: RM
authors.lastname: Amos-Kroohs
authors.affiliation: Division of Neurology (MLC 7044), Cincinnati Children's Research Foundation and Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.
authors.forename: Arnold
authors.initials: A
authors.lastname: Gutierrez
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
authors.forename: Kerstin H
authors.initials: KH
authors.lastname: Lundgren
authors.affiliation: Department of Neurology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
authors.forename: Kim B
authors.initials: KB
authors.lastname: Seroogy
authors.affiliation: Division of Neurology (MLC 7044), Cincinnati Children's Research Foundation and Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229, USA. Charles.Vorhees@cchmc.org.
authors.forename: Charles V
authors.initials: CV
authors.lastname: Vorhees
authors.affiliation: Division of Neurology (MLC 7044), Cincinnati Children's Research Foundation and Department of Pediatrics, University of Cincinnati College of Medicine, 3333 Burnet Ave., Cincinnati, OH, 45229, USA. Michael.Williams@cchmc.org.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Williams
mesh_terms: D000818:Animals; D015331:Cohort Studies; D004298:Dopamine / Q000172:deficiency*; D007859:Learning Disabilities / Q000378:metabolism; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D008569:Memory Disorders / Q000378:metabolism; D023421:Models, Animal; D009714:Nucleus Accumbens / Q000378:metabolism*; D016627:Oxidopamine / Q000633:toxicity*; D017397:Prefrontal Cortex / Q000378:metabolism*; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D065852:Spatial Memory / Q000502:physiology; D065854:Spatial Navigation / Q000502:physiology*
chemical_list: D016627:Oxidopamine; D004298:Dopamine
keywords: Allocentric learning and memory; Dopamine; Egocentric learning and memory; Neostriatum; Prefrontal cortex