title: Functional regeneration of intraspinal connections in a new in vitro model.
abstract: Regeneration in the adult mammalian spinal cord is limited due to intrinsic properties of mature neurons and a hostile environment, mainly provided by central nervous system myelin and reactive astrocytes. Recent results indicate that propriospinal connections are a promising target for intervention to improve functional recovery. To study this functional regeneration in vitro we developed a model consisting of two organotypic spinal cord slices placed adjacently on multi-electrode arrays. The electrodes allow us to record the spontaneously occurring neuronal activity, which is often organized in network bursts. Within a few days in vitro (DIV), these bursts become synchronized between the two slices due to the formation of axonal connections. We cut them with a scalpel at different time points in vitro and record the neuronal activity 3 weeks later. The functional recovery ability was assessed by calculating the percentage of synchronized bursts between the two slices. We found that cultures lesioned at a young age (7-9 DIV) retained the high regeneration ability of embryonic tissue. However, cultures lesioned at older ages (>19 DIV) displayed a distinct reduction of synchronized activity. This reduction was not accompanied by an inability for axons to cross the lesion site. We show that functional regeneration in these old cultures can be improved by increasing the intracellular cAMP level with Rolipram or by placing a young slice next to an old one directly after the lesion. We conclude that co-cultures of two spinal cord slices are an appropriate model to study functional regeneration of intraspinal connections.
authors.affiliation: Department of Physiology, University of Bern, Bühlplatz 5, 3012 Bern, Switzerland. Electronic address: heidemann@pyl.unibe.ch.
authors.forename: M
authors.initials: M
authors.lastname: Heidemann
authors.affiliation: Department of Physiology, University of Bern, Bühlplatz 5, 3012 Bern, Switzerland. Electronic address: streit@pyl.unibe.ch.
authors.forename: J
authors.initials: J
authors.lastname: Streit
authors.affiliation: Department of Physiology, University of Bern, Bühlplatz 5, 3012 Bern, Switzerland. Electronic address: tscherter@pyl.unibe.ch.
authors.forename: A
authors.initials: A
authors.lastname: Tscherter
mesh_terms: D000200:Action Potentials; D000367:Age Factors; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology; D004566:Electrodes; D005455:Fluorescent Antibody Technique; D066298:In Vitro Techniques; D008959:Models, Neurological; D009416:Nerve Regeneration / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D051381:Rats; D055647:Rats, Transgenic; D017208:Rats, Wistar; D020127:Recovery of Function / Q000187:drug effects / Q000502:physiology*; D020889:Rolipram / Q000494:pharmacology; D013116:Spinal Cord / Q000187:drug effects / Q000196:embryology / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000188:drug therapy / Q000503:physiopathology*; D046509:Tissue Culture Techniques
chemical_list: D018696:Neuroprotective Agents; D020889:Rolipram
keywords: multi-electrode array; organotypic cultures; regeneration; spinal cord