P2 nucleotide receptors in peripheral nerve trunk

2001 ◽  
Vol 52 (1-2) ◽  
pp. 83-88 ◽  
Author(s):  
Dominik Irnich ◽  
Ralf Burgstahler ◽  
Peter Grafe
Glia ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 367-376 ◽  
Author(s):  
S. Jeffrey Dixon ◽  
Rongguo Yu ◽  
Nattapon Panupinthu ◽  
John X. Wilson

1997 ◽  
Vol 22 (1) ◽  
pp. 57-60 ◽  
Author(s):  
T. E. J. HEMS ◽  
P. D. BURGE ◽  
D. J. WILSON

Fourteen cases of peripheral nerve tumour which had been examined by MRI were reviewed. T1-weighted images showed the tumours to be of intermediate signal and T2-weighted images showed a high signal with some heterogeneity. These appearances are not specific to peripheral nerve tumours, although the diagnosis may be suggested if the lesion arises from a major nerve trunk. The association with a nerve trunk may be defined by MRI, thus assisting with surgical planning. Neurilemmomas, neurofibromas and malignant nerve sheath tumours could not be differentiated with certainty using MR alone. The MR features of lipofibromatous hamartoma are reported.


1994 ◽  
Vol 71 (1) ◽  
pp. 216-228 ◽  
Author(s):  
S. Jeftinija ◽  
L. Urban

1. The effects of repetitive stimulation of primary afferents in lumbar dorsal roots on synaptic transmission in the dorsal horn (DH) were studied in a rat spinal cord slice-dorsal root ganglion (DRG)-peripheral nerve trunk preparation by the use of intracellular recording from neurons (n = 115) of the spinal dorsal horn (depth 147 +/- 139, mean +/- SD). All DH neurons were excited synaptically by electrical stimulation of the dorsal root or the peripheral nerve trunk. The electrical shocks were calibrated to produce activation either of large fibers (10–20 V, 0.02 ms) or the whole fiber population including unmyelinated afferents (supramaximal stimulus: > 35 V, 0.5 ms). Postsynaptic potentials induced by low intensity repetitive stimulation of primary afferents at frequencies below 5 Hz failed to produce a prolonged change in the resting membrane potential. In 97/115 DH neurons, slow excitatory postsynaptic potentials (EPSP)--evoked by high intensity low-frequency repetitive stimulation (0.1–2 Hz) of primary afferents--summated, producing a prolonged cumulative depolarization. In the remaining 18/115 DH neurons, high intensity low-frequency stimulation produced a cumulative hyperpolarizing response. 2. In 22 of 97 neurons that responded to high intensity repetitive stimulation with a cumulative depolarization, wind-up in the firing of action potentials was recorded. In all but two experiments, neurons that responded with wind-up to stimulation of one root responded with wind-up to stimulation of the adjacent dorsal root. In 14/22 wind-up neurons, the synaptic response to high intensity stimulation of primary afferents was composed of a short latency EPSP, followed by an inhibitory postsynaptic potential (IPSP), followed by a slow EPSP. The decrease of the amplitude and duration of the IPSP obtained during train stimulation did not seem to contribute to facilitation of transmission induced by repetitive stimulation. 3. The wind-up in firing of action potentials was followed by a prolonged potentiation of synaptic transmission in tetanized synapses. A test of other, adjacent primary afferents revealed that these synapses in the neurons in the superficial laminae had not undergone potentiation. This “synaptic specificity” of post-wind-up potentiation suggested that the mechanism for the induction of stimulation-dependent changes in the excitability of the DH neuron is presynaptic to the recorded-from neuron. 4. In a concentration of 0.5 microM and higher, tetrodotoxin (TTX) applied to sensory neurons selectively blocked action potentials in large myelinated primary afferents.(ABSTRACT TRUNCATED AT 400 WORDS)


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