Why am I lost without dopamine? Effects of 6-OHDA lesion on the encoding of reward and decision process in CA3
Neurobiology of Disease. 2013-11-01; 59: 151-164
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1. Neurobiol Dis. 2013 Nov;59:151-64. doi: 10.1016/j.nbd.2013.07.014. Epub 2013 Aug
Why am I lost without dopamine? Effects of 6-OHDA lesion on the encoding of
reward and decision process in CA3.
Retailleau A(1), Dejean C, Fourneaux B, Leinekugel X, Boraud T.
(1)University of Bordeaux, Institut des Maladies Neurodegeneratives UMR 5293,
Bordeaux, France; CNRS, Institut des Maladies Neurodegeneratives UMR 5293,
There is growing evidence that Parkinson’s disease, generally characterized by
motor symptoms, also causes cognitive impairment such as spatial disorientation.
The hippocampus is a critical structure for spatial navigation and receives
sparse but comprehensive dopamine (DA) innervation. DA loss is known to be the
cause of Parkinson’s disease and therefore it has been hypothesized that the
associated spatial disorientation could result from hippocampal dysfunction.
Because DA is involved in the prediction of reward expectation, it is possible to
infer that spatial disorientation in DA depleted subjects results from the loss
of the ability to detect the rewarding features within the environment. Amongst
hippocampal formation subdivisions, CA3 properties such as the high liability of
its place fields make it a serious candidate for interfacing DA reward system and
spatial information encoding. We addressed this issue using multiple electrode
recordings of CA3 in normal and dopamine depleted rats performing a spatial
learning in a Y-maze. Our data confirm that DA is essential to spatial learning
as its depletion results in spatial impairments. The present work also shows that
CA3 involvement in the detection of spatial feature contextual significance is
under DA control. Finally, it also shows that CA3 contributes to the decision
making processes of navigation tasks. The data also reveal a lateralization
effect of DA depletion underlined by neural correlates.
PMID: 23911573 [Indexed for MEDLINE]