title: Dopamine-containing neurons are silenced by energy deprivation: a defensive response or beginning of cell death?
abstract: Metabolic stress associated to mitochondrial dysfunction has been put forward as an important factor causing degeneration of mesencephalic dopamine-containing neurons in Parkinson's disease (PD). Here we overview how these neurons react to acute hypoxia or hypoglycemia, that are conditions of energy deprivation causing a reduced production of ATP by mitochondria. These neurons, which show a tonic firing discharge under normal condition, undergo into membrane hyperpolarization during hypoxia or hypoglycemia that silence their spontaneous activity. We outline the cellular mechanisms causing membrane hyperpolarization and the accompanied disturbances of intracellular calcium and sodium homeostasis. A better understanding of the changes occurring during transient energy deprivation might contribute to understand the physiopathology of these neurons that derives from mitochondrial dysfunction.
authors.affiliation: Fondazione Santa Lucia IRCCS-Laboratorio di Neurologia Sperimentale, Via Ardeatina 306, Fondazione Santa Lucia IRCCS, 00179 Rome, Italy. e.guatteohsantalucia.it
authors.forename: Ezia
authors.initials: E
authors.lastname: Guatteo
authors.forename: Silvia
authors.initials: S
authors.lastname: Marinelli
authors.forename: Raffaella
authors.initials: R
authors.lastname: Geracitano
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tozzi
authors.forename: Mauro
authors.initials: M
authors.lastname: Federici
authors.forename: Giorgio
authors.initials: G
authors.lastname: Bernardi
authors.forename: Nicola B
authors.initials: NB
authors.lastname: Mercuri
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology; D004298:Dopamine / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007003:Hypoglycemia / Q000473:pathology; D000860:Hypoxia / Q000473:pathology; D007473:Ion Channels / Q000502:physiology; D009474:Neurons / Q000378:metabolism / Q000502:physiology*
chemical_list: D007473:Ion Channels; D004298:Dopamine