Quantitative immunofluorescence for BDNF, NGF, and NT-3 in Schwann cells of the spinal roots and peripheral nerve
| Authors | |
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| Year of publication | 2002 |
| Type | Article in Proceedings |
| Conference | Progress in Basic, Applied, and Diagnostic Histochemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Morphological specializations and cytology |
| Keywords | neurotrophins; immunofluorescence; image analysis |
| Description | Axotomy induces development of a microenvironment supporting axonal regeneration in the peripheral nervous system. The promotion of axonal regeneration is related with up-regulation of many molecules including neurotrophins in reactive Schwann cells. The dorsal and ventral spinal roots contain a dominant amount of afferent and motor axons, respectively. Besides differences of intrinsic capacities of the sensory and motor neurons for axon regeneration, we hypothesize different cellular and extracellular conditions alongside afferent and motor axons. We have optimized indirect immunofluorescence method for quantitative investigation of neurotrophins (BDNF, NGF and NT-3). The cryostat sections (8 ľm) through the intact and 14-day-rhizotomized dorsal and ventral roots as well as intact and 14-day-transected femoral nerves were cut and incubated simultaneously. An intensity of immunofluorescence staining expressed was compared using the computer-assisted image analysis (Lucia-G v 4.21). Immunofluorescence intensity for BDNF, NGF and NT-3 was higher in the Schwann cells of cutaneous than motor branches of the intact femoral nerve. On the other hand, a higher intensity for BDNF and NT-3 immunofluorescence was measured in the Schwann cells of the intact dorsal than ventral roots while no difference was found for NFG immunostaining. Two weeks after rhizotomy or nerve transection immunofluorescence intensity for investigated neurotrophins was significantly higher in all distal Schwann cells in comparison to the ones of the intact roots or nerves. In addition, intensity of immunofluorescence for BDNF, NGF and NT-3 was very similar in the Schwann cells of both motor and cutaneous branches two weeks after transection of the femoral nerve. Comparing the Schwann cells of rhizotomized roots the immunofluorescence was significantly higher in the ventral than dorsal roots. The results of quantitative immunofluorescence staining revealed that the axotomy-induced up-regulation of neurotrophins is different in the Schwann cells of spinal roots and peripheral nerves. In addition, there is a different up-regulation of neurotrophins in the reactive Schwann cells alongside afferent and motor axons of the spinal roots preparing different condition for their regeneration. |
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