Journal Article

Functional Integration of Grafted Neural Stem Cell-Derived Dopaminergic Neurons Monitored by Optogenetics in an In Vitro Parkinson Model

Sørensen, Andreas T., Kokaia, Merab, Deisseroth, Karl, Lundberg, Cecilia, Arenas, Ernest, Tønnesen, Jan, Andersson, Angelica, Lindvall, Olle, Parish, Clare L.

2011

Overview

Intrastriatal grafts of stem cell-derived dopamine (DA) neurons induce behavioral recovery in animal models of Parkinson's disease (PD), but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral mesencephalon of tyrosine hydroxylase-GFP transgenic mice were expanded as neurospheres and transplanted into organotypic cultures of wild type mouse striatum. Differentiated GFP-labeled DA neurons in the grafts exhibited mature neuronal properties, including spontaneous firing of action potentials, presence of post-synaptic currents, and functional expression of DA D₂ autoreceptors. These properties resembled those recorded from identical cells in acute slices of intrastriatal grafts in the 6-hydroxy-DA-induced mouse PD model and from DA neurons in intact substantia nigra. Optogenetic activation or inhibition of grafted cells and host neurons using channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR), respectively, revealed complex, bi-directional synaptic interactions between grafted cells and host neurons and extensive synaptic connectivity within the graft. Our data demonstrate for the first time using optogenetics that ectopically grafted stem cell-derived DA neurons become functionally integrated in the DA-denervated striatum. Further optogenetic dissection of the synaptic wiring between grafted and host neurons will be crucial to clarify the cellular and synaptic mechanisms underlying behavioral recovery as well as adverse effects following stem cell-based DA cell replacement strategies in PD.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Action potential / Action Potentials - physiology / Analysis / Animal diseases / Animal models / Animals / Basic Medicine / Biochemistry / Biology / Biophysics / Brain / Brain slice preparation / Cell culture / Cell Shape / Channelrhodopsins / Clinical Medicine / Developmental biology / Dissection / Dopamine / Dopamine - metabolism / Dopamine D2 receptors / Dopamine receptors / Embryo cells / Embryos / Epilepsy / Functional integration / Genetic engineering / Genetics / Glucose / Grafting / Grafts / Handbooks / Hospitals / Hydroxylase / In Vitro Techniques / Information processing / Integration / Klinisk medicin / Laboratories / Medical and Health Sciences / Medicin och hälsovetenskap / Medicine / Medicinska och farmaceutiska grundvetenskaper / Mesencephalon / Mesencephalon - pathology / Mesencephalon - physiopathology / Mice / Models, Biological / Movement disorders / Neostriatum / Neural circuitry / Neural networks / Neural stem cells / Neural Stem Cells - cytology / Neural Stem Cells - transplantation / Neurobiology / Neurodegenerative diseases / Neurologi / Neurology / Neurons / Neurons - cytology / Neurons - transplantation / Neurosciences / Neurospheres / Neurovetenskaper / Optics / Optics and Photonics - methods / Parkinson Disease - physiopathology / Parkinson Disease - therapy / Parkinson's disease / Penicillin / Recovery / Stem cell transplantation / Stem cells / Substantia nigra / Synapses - metabolism / Transgenic mice / Transmitters / Transplants & implants / Trends / Tyrosine / Tyrosine 3-monooxygenase / Wiring / Wnt protein