Transplants of syngenic cultured, DRG-derived Schwann cells into the injured adult rat spinal cord.

Conference (1993, June 18)

Traiter chirurgicalement les anévrismes du système vertébro-basilaire comme les autres anévrismes ?

Conference (1993, June 08)

Kystes dermoïdes récidivant en kystes épidermoïdes.

Conference (1993, March 13)

Transforming growth factor ß as a neuronoglial signal during peripheral nervous sytem response to injury.

in Journal of Neuroscience Research (1993), 34

Plasticity of Developing and Adult Dorsal Root Ganglion Neurons as Revealed in Vitro

in Brain Research Bulletin (1993), 30(3-4), 231-7

We review recent data on the plasticity of dorsal root ganglion (DRG) neurons as revealed during cultivation in vitro. Some experiments on cultured developing DRG neurons and on adult DRG neurons in vivo ... [more ▼]

We review recent data on the plasticity of dorsal root ganglion (DRG) neurons as revealed during cultivation in vitro. Some experiments on cultured developing DRG neurons and on adult DRG neurons in vivo are also mentioned. Cultured developing and adult DRG neurons can be switched from an apolar to a multipolar phenotype by fetal calf serum or fibronectin. The effect is concentration dependent and occurs through an early modification of cell-substratum interaction. Adult DRG neurons synthesize and release within hours after injury TGF beta-1, which is a mitogen and a differentiation factor for Schwann cells. Finally, adult DRG neurons express in vitro neurotransmitters that are not expressed in vivo. This neurotransmitter plasticity can be modulated in vitro by some growth factors and in vivo by distal or proximal axotomy. [less ▲]

Acute Traumatic Central Cord Syndrome: Clinical, Magnetic Resonance and Pathological Features

Conference (1993)

Administration de Sandostatine (octréotide) avant chirurgie transphénoïdale dans l'acromégalie

Conference (1992, November 30)

In Vitro and in Vivo Modulation of 5-Hydroxytryptamine-, Thyrotropin-Releasing Hormone- and Calcitonin-Gene Related Peptide-Like Immunoreactivities in Adult Rat Sensory Neurons

in Neuroscience (1992), 51(2), 401-10

In a previous work we have shown that culturing adult rat dorsal root ganglia neurons modifies their neurotransmitter phenotype in such a way that cultured neurons synthesize transmitters that are not ... [more ▼]

In a previous work we have shown that culturing adult rat dorsal root ganglia neurons modifies their neurotransmitter phenotype in such a way that cultured neurons synthesize transmitters that are not found in situ, while several other transmitters are expressed in a much higher percentage of neurons in culture than in situ [Schoenen J. et al. (1989) J. Neurosci. Res. 22, 473-487]. The aim of the present study was to investigate the origin and the nature of the relevant environmental signals that allow this plasticity to be expressed, focusing on three neurotransmitters: 5-hydroxytryptamine, thyrotropin-releasing hormone and calcitonin-gene related peptide. The main results can be summarized as follows: (1) culturing cells in fetal calf serum or on feeder layers of astrocytes, Schwann cells or fibroblasts partially inhibits the serotoninergic phenotype of dorsal root ganglia neurons; (2) in vivo disconnection of dorsal root ganglia from their spinal targets but not from their peripheral or supraspinal targets induces a significant increase of the percentage of 5-hydroxytryptamine- and thyrotropin-releasing hormone-positive neurons in disconnected ganglia; (3) growth factors such as ciliary neuronotrophic factor or basic fibroblast growth factor but not nerve growth factor repress 5-hydroxytryptamine and calcitonin gene-related peptide immunoreactivity in cultured sensory neurons. In conclusion, neurotransmitter gene expression of adult dorsal root ganglia neurons is controlled by complex influences. Our data suggest that thyrotropin-releasing hormone and 5-hydroxytryptamine gene expression are tonically repressed in vivo by factors originating from the spinal segmental level and that growth factors such as ciliary neurotrophic factor or basic fibroblast growth factor could be potential vectors of this repressing effect. [less ▲]

Transplants of syngenic cultured, DRG-derived Schwann cells into the lesioned adult rat spinal cord.

Conference (1992, September 08)

Experimental Acute Traumatic Injury of the Adult Rat Spinal Cord by a Subdural Inflatable Balloon: Methodology, Behavioral Analysis, and Histopathology

in Journal of Neuroscience Research (1992), 32(4), 539-50

We describe an experimental model to produce closed traumatic injuries to the spinal cord of adult rats. This model uses an inflatable balloon that is introduced in the dorsal subdural space and moved to ... [more ▼]

We describe an experimental model to produce closed traumatic injuries to the spinal cord of adult rats. This model uses an inflatable balloon that is introduced in the dorsal subdural space and moved to a location rostral to the laminectomy site. The spinal cord trauma can be graded by varying either the duration of compression or the volume of saline used to inflate the balloon. The locomotor deficit of animals with various degrees of injury has been assessed at increasing delays after trauma. The parameters generating transient or definitive deficits of varying intensity were defined. Some injured animals underwent nuclear magnetic resonance imaging. Detailed histopathological studies demonstrated that the extent of the spinal lesion was significantly correlated with the physical parameters of compression and with the severity of the behavioral deficit. [less ▲]