title: Functional regeneration of the ex-vivo reconstructed mesocorticolimbic dopaminergic system.
abstract: CNS reparative-medicine therapeutic strategies need answers on the putative recapitulation of the basic rules leading to mammalian CNS development. To achieve this aim, we focus on the regeneration of functional connections in the mesocorticolimbic dopaminergic system. We used organotypic slice cocultures of ventral tegmental area/substantia nigra (VTA/SN) and prefrontal cortex (PFC) on a multielectrode array (MEA) platform to record spikes and local field potentials. The spontaneously growing synaptically based bidirectional bursting activity was followed from 2 to 28 days in vitro (DIV). A statistical analysis of excitatory and inhibitory neurons properties of the physiological firing activity demonstrated a remarkable, exponentially increasing maturation with a time constant of about 5-7 DIV. Immunohistochemistry demonstrated that the ratio of excitatory/inhibitory neurons (3:1) was in line with the functional results obtained. Exemplary pharmacology suggested that GABAA receptors were able to exert phasic and tonic inhibition typical of an adulthood network. Moreover, dopamine D2 receptor inactivation was equally inhibitory both on the spontaneous neuronal activity recorded by MEA and on patch-clamp electrophysiology in PFC pyramidal neurons. These results demonstrate that axon growth cones reach synaptic targets up to full functionality and that organotypic cocultures of the VTA/SN-PFC perfectly model their newly born dopaminergic, glutamatergic and GABAergic neuronal circuitries.
authors.affiliation: Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Dossi
authors.forename: Claudia
authors.initials: C
authors.lastname: Heine
authors.forename: Ilenio
authors.initials: I
authors.lastname: Servettini
authors.forename: Francesca
authors.initials: F
authors.lastname: Gullo
authors.forename: Katja
authors.initials: K
authors.lastname: Sygnecka
authors.forename: Heike
authors.initials: H
authors.lastname: Franke
authors.forename: Peter
authors.initials: P
authors.lastname: Illes
authors.forename: Enzo
authors.initials: E
authors.lastname: Wanke
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D059290:Dopaminergic Neurons / Q000502:physiology; D059330:GABAergic Neurons / Q000502:physiology; D051379:Mice; D009415:Nerve Net / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D012038:Regeneration; D013378:Substantia Nigra / Q000502:physiology*; D017557:Ventral Tegmental Area / Q000502:physiology*