D A Utzschneider

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1. Intraaxonal recordings were obtained in vitro from the sural nerve (SN), the muscle branch of the anterior tibial nerve (ATN), or the deafferented ATN (dATN) in 5- to 7-wk-old rats. Whole-nerve sucrose gap recordings were obtained from the SN and the ATN. This allowed study of cutaneous (SN), mixed motor and muscle afferent (ATN), and isolated muscle(More)
A central issue in transplantation research is to determine how and when transplantation of neural tissue can influence the development and function of the mammalian central nervous system. Of particular interest is whether electrophysiological function in the traumatized or diseased mammalian central nervous system can be improved by the replacement of(More)
Intracellular recordings were obtained from primary sensory neurons in excised dorsal root ganglia (DRGs). Most (90%) neurons sampled became depolarized during periods of repetitive stimulation of a branch of the dorsal root (DR) which contained only axons of neighboring neurons. DR stimulation also evoked a transient rise in extracellular K+ concentration(More)
Myelinated primary afferent fibers have both peripheral and central nervous system components. As the fibers course through peripheral nerve and dorsal roots they are myelinated by Schwann cells, but after they invade the spinal cord they become myelinated by oligodendrocytes and have associations with astrocytes. This presents the opportunity to compare(More)
Confocal microscopy and the Ca(2+)-sensitive fluorescent dye fluo-3 were used to study subcellular Ca2+ signals in embryonic, neonatal, and adult dorsal root ganglion (DRG) neurons in excised dorsal root ganglia. Optical images obtained from isolated whole embryonic and neonatal ganglia revealed a marked variability in the resting Ca2+ signals of different(More)
Compound action potential (CAP) conduction and Na+ channel content were studied in optic nerves from control and myelin-deficient (md) rats. Action potential propagation was approximately five times slower in the md rat, but the action potentials propagated securely and had frequency-following and refractory properties equivalent to control myelinated(More)
GABA (gamma-aminobutyric acid) can modulate axonal excitability by activating GABAA receptors on some central nervous system axons. The effects of GABA on optic nerve axons decrease significantly during the course of myelination, suggesting that myelination may influence changes in GABA sensitivity. To test this hypothesis, we compared the depolarizing(More)
Spinal cords of myelin-deficient and normal age-matched (control) rats were removed and their conduction and pharmacological properties studied in an in vitro brain slice chamber. The conduction velocity of the myelin-deficient dorsal column axons was reduced to about 25% of control axons; however, the amyelinated myelin-deficient axons displayed refractory(More)
Excitability of rat dorsal root axons were studied 3 weeks after injury to the sciatic nerve. Whole nerve recordings were obtained from injured and control nerves in a sucrose gap chamber. Constant current depolarization pulses (30-200 ms) applied approximately 50% above the stimulus strength required for maximal amplitude compound action potentials (CAPs)(More)
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