Search Results - (Author, Cooperation:C. J. Woolf)

2014-10-14

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

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Alzheimer Disease/genetics/*metabolism/*pathology ; Amyloid beta-Peptides/chemistry/genetics/metabolism ; Cell Culture Techniques/*methods ; Cell Differentiation ; Drug Evaluation, Preclinical/methods ; Extracellular Space/metabolism ; Glycogen Synthase Kinase 3/metabolism ; Humans ; Microtubule-Associated Proteins/metabolism ; *Models, Biological ; Neural Stem Cells/*metabolism/pathology ; Neurites/metabolism ; Phosphorylation ; Presenilin-1/metabolism ; Protein Aggregation, Pathological ; Reproducibility of Results ; tau Proteins/chemistry/metabolism

2013-03-12

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amyotrophic Lateral Sclerosis ; Animals ; Animals, Newborn ; Axons/metabolism/pathology ; Cell Death ; Diaphragm/innervation ; Embryo Loss ; Embryo, Mammalian/metabolism/pathology ; Exons/genetics ; Female ; Fibroblasts ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mice, Transgenic ; Motor Neurons/*metabolism/*pathology ; Muscular Atrophy, Spinal ; Neuromuscular Diseases/metabolism/pathology ; Oxidative Stress ; RNA Processing, Post-Transcriptional ; RNA, Transfer, Tyr/genetics/*metabolism ; Respiration ; Spinal Nerves/cytology ; Transcription Factors/deficiency/*metabolism ; Tumor Suppressor Protein p53/metabolism ; Tyrosine/genetics/metabolism

2013-08-24

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Action Potentials ; Animals ; Bacterial Load ; Calcium Signaling ; Female ; Hemolysin Proteins/metabolism ; Host-Pathogen Interactions ; Hot Temperature ; Hyperalgesia/microbiology ; Immunity, Innate ; Inflammation/immunology/metabolism/*microbiology/pathology ; Lymphatic Diseases/immunology/microbiology/pathology ; Male ; Mice ; Mice, Inbred C57BL ; Monocytes ; Myeloid Differentiation Factor 88/immunology ; N-Formylmethionine Leucyl-Phenylalanine/metabolism ; NAV1.8 Voltage-Gated Sodium Channel/deficiency/immunology/metabolism ; Neutrophils ; Nociceptors/*metabolism ; Pain/immunology/metabolism/*microbiology/*physiopathology ; Protein Stability ; Staphylococcal Infections/immunology/metabolism/microbiology ; Staphylococcus aureus/immunology/metabolism/*pathogenicity ; Toll-Like Receptor 2/immunology

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The expression of growth-associated protein GAP-43 mRNA in spinal cord and dorsal root ganglion (DRG) neurons has been studied using an enzyme linked in situ hybridization technique in neonatal and adult rats. High levels of GAP-43 mRNA are present at birth in the majority of spinal cord neurons and in all dorsal root ganglion cells. This persists until postnatal day 7 and then declines progressively to near adult levels (with low levels of mRNA in spinal cord motor neurons and 2000–3000 DRG cells expressing high levels) at postnatal day 21. A re-expression of GAP-43 mRNA in adult rats is apparent, both in sciatic motor neurons and the majority of L4 and L5 dorsal root ganglion cells, 1 day after sciatic nerve section. High levels of the GAP-43 mRNA in the axotomized spinal motor neurons persist for at least 2 weeks but decline 5 weeks after sciatic nerve section, with the mRNA virtually undetectable after 10 weeks. The initial changes after sciatic nerve crush are similar, but by 5 weeks GAP-43 mRNA in the sciatic motor neurons has declined to control levels. In DRG cells, after both sciatic nerve section or crush, GAP-43 mRNA re-expression persists much longer than in motor neurons. There was no re-expression of GAP-43 mRNA in the dorsal horn of the spinal cord after peripheral nerve lesions. Our study demonstrates a similar developmental regulation in spinal cord and DRG neurons of GAP-43 mRNA. We show moreover that failure of re-innervation does not result in a maintenance of GAP-43 mRNA in axotomized motor neurons.

Electronic Resource

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The effects of morphine on the depolarizing synaptic responses produced in motoneurons by electrical stimulation of primary sensory neurones have been recorded in hemisected spinal cord preparations (8- to 12-day-old rat pups). Morphine at concentrations of 0.1-20 μM reduced a slow, long-lasting (latency greater than 1 s, duration up to 10 s) component of the ventral root potential (VRP) evoked by C-fibre strength stimulation of the dorsal root. At 2μM the reduction in area of this slow synaptic potential was 71.7 ± 0.9% of control values (n= 15). The earliest components of the C-fibre strength VRP (the first 100 ms) and the responses to Aβ strength stimuli were unaffected by the opioid even at 10-20μM. The intermediate, NMDA receptor antagonist (D-AP5, 40μM)-sensitive component (which lasts 100-1000 ms) was reduced by 34 ± 2.2% of control (n= 15), which was significantly less than the reduction of the later NMDA-independent component (P 〈 0.001). Morphine (0.1-20 μM) also depressed the cumulative depolarization generated by the temporal summation of synaptic responses evoked by brief trains of C-fibre strength stimuli (1 or 10 Hz). A significantly greater reduction at the lower frequency of stimulation (56.3 ± 2.0%) than at the higher (20.3 ± 1.69%, n = 10, measured at 2 μM morphine) was found (P 〈 0.005). The effects of morphine were reversible upon wash-out or superfusion with the opioid receptor antagonist naloxone (2 μM). The depression in the C-fibre-evoked VRPs produced by the NMDA receptor antagonist D-AP5 (10-40 μM) was different from that produced by morphine, as D-AP5 only reduced a shorter latency component of the VRP (100 ms-1 s) and was equally effective in decreasing the cumulative depolarizations evoked by 1 and 10 Hz trains. The preferential effect of morphine on the longest latency and longest lasting components of the high-threshold VRP are discussed in relation to its possible site and mechanism of analgesic action.

Electronic Resource

1460-9568

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The synaptic responses of lumbar ventral horn neurons including identified flexor motoneurons, to graded stimulation of peripheral nerves have been recorded in vitro in the young rat spinal cord-hindlimb preparation. Single shock stimulation of low threshold myelinated afferents evoked short latency (〈 20 ms) short duration (〈1.0 s, 391 ± 42 ms n = 43 SEM) compositive mono- and polysynaptic potentials. Recruitment of both thinly myelinated (A delta) and unmyelinated (C) afferent fibres elicited a prolonged postsynaptic depolarization (〉 1 s) in all cells. In the majority of cells (67.4%), this depolarization exceeded 4.0 s in duration (8.01 ± 0.4 s, n = 26, maximum 14 s). In the remainder, shorter responses were evoked (〈 3.0 s, mean = 1.74 ± 0.4 s, n = 18). In those cells where the postsynaptic response to a single A delta or C fibre strength stimulus exceeded 4 s, low frequency (0.5–1.0 Hz) repetitive stimulation resulted in a temporal summation of the postsynaptic depolarizations, which generated a cumulatively increasing depolarization. This incrementing depolarization was sufficient in 33% of the cells to produce a progressive increase in spike discharge (windup). On cessation of the train of stimuli the depolarization decayed slowly (65 ± 27 s). The N-methyl D-aspartic acid (NMDA) receptor antagonist D-2-amino-5-phosphonovaleric acid (d-APV) reduced the duration and amplitude of the prolonged postsynaptic depolarizations elicited by a single shock stimulation of small diameter afferents by 57% and 50% respectively. A smaller effect was produced on the low threshold afferent evoked early excitatory postsynaptic potentials (EPSP) (3% decrease in amplitude and 24% decrease in duration). In the presence of d-APV the cumulatively incrementing depolarization produced by repetitive stimulation was substantially reduced and windup failed to occur. Activity-dependent amplifications of primary afferent evoked responses in spinal neurons therefore involves a temporal summation of d-APV sensitive prolonged postsynaptic depolarizations.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] ALTHOUGH an ever-increasing number of pharmacologically active peptides are being found in neurones of the central nervous system, it is still not proving possible to find out precisely what neuro-transmitter or neuromodulator functions they perform. This may not be so surprising when one remembers ...

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Control fish acclimated at 21°C learned to swim upright following the attachment of floats to their ventral surfaces, while fish acclimated at both 5°C and 33°C failed to learn the swimming skill. Fish previously acclimated at 5°C and then transferred to 21°C 48 h before the task, learnt the swimming skill better than the control fish, but fish acclimated at 33°C and transferred to 21°C failed to acquire the new skill. Acclimation temperature, therefore, significantly modifies the learning behaviour of fish.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] A RECENT article in these columns1 by Chung and Dickenson discusses the relationship between pain, the enkephalins and acupuncture. We are told that "placing a single needle into a certain point of the body can produce ... a potent amelioration of pain". It is proposed that acupuncture analgesia ...

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Zusammenfassung Veränderungen am neurochemischen Korrelat des Erinnerungs- und Lernvermögens im Fisch erwiesen sich als zeitabhängig.

Electronic Resource

1432-1106

Dorsal horn ; Unmyelinated (C) fibres ; Spinal cord ; Habituation ; Post-tetanic inhibition

Springer Online Journal Archives 1860-2000

Medicine

Summary The effect of repetitive primary afferent C-fibre stimulation on the responses of single wide dynamic range neurones recorded in the dorsal horn of the spinal cord have been exaemined in the unanaesthetised decerebrate-spinal rat. Prolonged stimulation of the sural nerve at 0.5 Hz or higher produced both a progressive increase in the latency of the sural evoked C-responses in all units and a decrease or habituation of the number of C-evoked spikes in the majority of units (62%) recorded in laminae 5 and 6. The shift in latency of the C responses in the dorsal horn neurones was found to be the result of an activity-dependent reduction in the conduction velocity of the primary afferent C-fibres, but such stimulation did not decrease the size of the C compound action potential or produce a block in conduction of single polymodal C-fibres which could account for the habituation of the dorsal horn neurones. A complete habituation or failure of the C-evoked response in a dorsal horn neurone produced by repetitive stimulation of a peripheral nerve was associated with a reduction but not the abolishment of the convergent C-input from an adjacent untetanized nerve, indicating that the habituation did not occur as the result of a postsynaptic inhibition of the dorsal horn neurone. Following a C-tetanus (10 Hz for 10 s) applied to the sural nerve a short and partial homosynaptic post-tetanic inhibition of the subsequent C responses evoked from the sural occurs. Such sural nerve C-tetani however produced a much more powerful and prolonged heterosynaptic post-tetanic inhibition of the C-responses evoked from the common peroneal nerve in those units with convergent C-input from both these two adjacent nerves. None of the effects of repetitive peripheral C-fibre stimulation on the C-evoked responses in the dorsal horn could be produced by A-fibre conditioning stimuli applied at identical frequencies. These results indicate that there is a segmentally organized C afferent-mediated inhibition of C-evoked responses in dorsal horn neurones that is generated both by the C-input that evoked those responses and by adjacent C-inputs.

Electronic Resource

1432-1904

Springer Online Journal Archives 1860-2000

Biology

Chemistry and Pharmacology

Natural Sciences in General

Electronic Resource

1573-7381

Springer Online Journal Archives 1860-2000

Medicine

Summary Terminal Schwann cells, when stained for S100 (a calcium binding protein), can be seen to cap motor axons at the neuromuscular junction. Within days of denervation the Schwann cells begin to stain for the low affinity nerve growth factor receptor, but remain Thy-1 negative, and elaborate fine processes. These processes become longer and more disorganized over weeks, and cells positive for S100 and nerve growth factor receptor migrate into the perisynaptic area. Reinnervation results in a withdrawal of the processes. The morphology and location of terminal Schwann cells seems to depend on axonal contact. The spread of Schwann cells and their processes away from the synaptic zone following denervation, implies that these cells do not target axons directly to the endplate.

Electronic Resource