کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
914109 | 918383 | 2011 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nerve growth factor selectively decreases activity-dependent conduction slowing in mechano-insensitive C-nociceptors
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علم عصب شناسی
علوم اعصاب سلولی و مولکولی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Nerve growth factor (NGF) induces acute sensitization of nociceptive sensory endings and long-lasting hyperalgesia. NGF modulation of sodium channel expression might contribute to neurotrophin-induced hyperalgesia. Here, we investigated NGF-evoked changes of the activity-dependent slowing of conduction in porcine C-fibers. Animals received intradermal injections of NGF (2 μg or 8 μg) or saline in both hind limbs. Extracellular recordings from the saphenous nerves were performed 1 week later. Based on sensory thresholds and electrically induced activity-dependent slowing (ADS) of axonal conduction, C-fibers were classified as mechano-sensitive afferents, mechano-insensitive afferents, cold nociceptors, and sympathetic efferents. NGF (2 μg) increased conduction velocity in C-fibers from 1.0 ± 0.05 m/s to 1.2 ± 0.07 m/s. In mechano-insensitive afferents, NGF (8 μg) reduced activity-dependent slowing of conduction, from 5.3 ± 0.2% to 3.2 ± 0.5% (0.125-0.5 Hz stimulation) and from 28.5 ± 1.3% to 20.9 ± 1.9% (2 Hz stimulation), such that ADS no longer differentiated between mechano-sensitive and mechano-insensitive fibers. Accordingly, the number of fibers with pronounced ADS decreased but more units with pronounced ADS were mechano-sensitive. Spontaneously active C-fibers were increased above the control level (1%) by NGF 8 μg (8%). The results demonstrate that NGF changes the functional axonal characteristics of mechano-insensitive C-fibers and enhances spontaneous activity thereby possibly contributing to hyperalgesia.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: PAIN - Volume 152, Issue 9, September 2011, Pages 2138-2146
Journal: PAIN - Volume 152, Issue 9, September 2011, Pages 2138-2146
نویسندگان
Otilia Obreja, Matthias Ringkamp, Brian Turnquist, Michael Hirth, Elmar Forsch, Roman Rukwied, Marlen Petersen, Martin Schmelz,