Expression of choline acetyltransferase and nerve growth factor receptor within hypoglossal motoneurons following nerve injury

Armstrong, David M.; Brady, Roseann; Hersh, Louis B.; Hayes, Robert C.; Wiley, Ronald G.

doi:10.1002/cne.903040407

Cited by 103 publications

(60 citation statements)

References 61 publications

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“…Nerve crush results in greater acute elevations in the levels of p75'@ mRNA reexpression as compared to nerve transection for both facial and hypoglossal motor neurons (Saika et al, 1991;Hayes et al, 1992). Furthermore, as compared to nerve transection, nerve crush results in smaller reductions in ChAT immunostaining in adult cranial motor neurons (Armstrong et al, 1991;Borke et al, 1993). The present study extends these findings to the RDLN spinal motor neurons where nerve crush injury both augments p75rn@ immunostaining and also reduces the loss in ChAT immunostaining relative to losses observed after nerve cut.…”

Section: Bdnf and Nt-415 Effects On Immunocytochemically Detectedsupporting

confidence: 73%

BDNF and NT-4/5 exert neurotrophic influences on injured adult spinal motor neurons

et al. 1995

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Adult motor neurons, like their immature antecedents, express the mRNA for the signaling receptor for brain-derived neurotrophic factor (BDNF) and for neurotrophin-4/5 (NT-4/5). However, while both BDNF and NT-4/5 support the survival of axotomized developing spinal motor neurons in vitro or in vivo, it is not known whether these factors continue to influence spinal motor neurons in adulthood. The present study tests if BDNF or NT-4/5 modulate the reactive responses of adult spinal motor neurons to nerve injury. We utilize sciatic nerve transection to axotomize the spinal motor neurons that form the retrodorsal lateral nucleus (RDLN) and show that, after axotomy, RDLN motor neurons lose ChAT immunoreactivity and also reexpress p75Ingfr, the low affinity receptor for all neurotrophin family members. Treatment with BDNF or NT- 4/5 alters these effects of sciatic nerve transection. Both BDNF and NT- 4/5 attenuate the loss of ChAT expression in axotomized RDLN motor neurons; thus, as compared to vehicle treatments, BDNF and NT-4/5 produce statistically significant increases in the optical density of ChAT immunostaining. Furthermore, BDNF and NT-4/5 also significantly increase the RDLN reexpression of p75Ingfr after sciatic nerve transection. Interestingly, essentially identical increases in RDLN ChAT and p75Ingfr immunostaining are produced by sciatic nerve crush injuries in the absence of exogenous neurotrophin treatment. These data show that treatment with exogenous BDNF and NT-4/5 changes the response of adult spinal motor neurons to sciatic nerve transection. Furthermore, these neurotrophins elicit reactive responses in axotomized motor neurons that mimic those produced by endogenous agents in regenerating crushed peripheral nerve.

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Section: Bdnf and Nt-415 Effects On Immunocytochemically Detectedsupporting

confidence: 73%

BDNF and NT-4/5 exert neurotrophic influences on injured adult spinal motor neurons

et al. 1995

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“…2), levels that were also comparable to agematched uncultured lumbar spinal cord tissue (data not shown). The initial drop in enzyme activity is a typical response of motor neurons to axotomy, not a loss ofcells; the return of ChAT activity reflects the recovery from this initial injury (7)(8)(9). This conclusion was supported by morphological analysis of the ventral motor neurons that were normal in appearance after a period of mild reversible chromatolytic changes limited to the first 3 weeks in culture (Fig.…”

Section: Resultsmentioning

confidence: 78%

“…Motor-neuron toxicity was monitored by two methods: (i) biochemical analysis of tissue choline acetyltransferase activity (ChAT) and (ii) microscopic morphology. ChAT activity is largely restricted to ventral motor neurons in rat lumbar spinal cord, and assays of ChAT activity have been used as a reliable marker for motor neurons (7)(8)(9). Motor neurons were also visualized in organotypic cultures by histological analysis of stained semithin plastic sections and by immunohistochemistry.…”

Section: Methodsmentioning

confidence: 99%

Chronic inhibition of glutamate uptake produces a model of slow neurotoxicity.

Rothstein

Jin

Dykes-Hoberg

et al. 1993

Proc. Natl. Acad. Sci. U.S.A.

566

350

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ABSTRACTprior to the addition of drugs. To produce chronic toxicity, long-term inhibition of glutamate uptake was effected by incubating slices with culture medium containing various concentrations of THA or PDC (5, 6). At very high concentrations (>1 mM), THA can have weak actions at the N-methyl-D-aspartate (NMDA) receptor, a property not shared by PDC (5). Transport inhibitors were maintained in cultures by replenishing them at each change in culture medium. In all experiments, potentially neuroprotective drugs were added repeatedly, either in the presence or absence of a glutamate transport inhibitor, again beginning after 8 days in culture. Motor-neuron toxicity was monitored by two methods: (i) biochemical analysis of tissue choline acetyltransferase activity (ChAT) and (ii) microscopic morphology. ChAT activity is largely restricted to ventral motor neurons in rat lumbar spinal cord, and assays of ChAT activity have been used as a reliable marker for motor neurons (7-9). Motor neurons were also visualized in organotypic cultures by histological analysis of stained semithin plastic sections and by immunohistochemistry.Organotypic Spinal Cord Cultures. Organotypic spinal cord cultures were prepared using lumbar spinal cord slices from 8-day-old rat pups. Neonatal rat pups were decapitated, and the spinal cords were rapidly harvested and cultured by a modification of described methods (10, 11). Lumbar spinal cords were collected under sterile conditions and sectioned transversely at 350-,um intervals with a McIlwain tissue chopper (Mickle Laboratory Engineering, Gomshall, Surrey, U.K.). Sections were then transferred to sterile Gey's balanced salt solution (GIBCO) containing glucose (6.4 mg/ml) and gently separated at room temperature. Slices were carefully placed on the surface of 30-mm Millipore Millicell-CM porous (0.4 ,um) membranes (five slices per membrane). Such tissue grows optimally at an air/fluid interface, so it was important to remove any excess medium on the membrane surface around slices. The membranes were placed in 35-mm culture wells (Nunc) containing 1 ml of incubation medium [50% (vol/vol) minimal essential medium-25 mM Hepes/ 25% (vol/vol) heat-inactivated horse serum/25% (vol/vol) Hanks' balanced salt solution (GIBCO) supplemented with D-glucose (25.6 mg/ml) and glutamine (2 mM), at a final pH of 7.2]. Initial studies using pH 7.4 or 7.8 revealed similar results. Antibiotic and antifungal agents were not used.Cultures were incubated at 37°C in a 5% C02/95% air humidified environment (Forma Scientific, Marietta, OH). Culture medium, along with any added pharmacological agents, was changed twice weekly. By using this technique, >95% of the explants can be maintained in culture for >3 months with excellent organotypic cellular organization.

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“…Upper airway dilator motor nuclei (moV, VII, and XII) were identified using landmarks in the Franklin and Paxinos (1997) mouse atlas. Within motor nuclei, motoneurons were identified by size Ͼ30 mm and immunoreactivity for choline acetyltransferase (ChAT) (Barber et al, 1984;Armstrong et al, 1991). The details for primary antibodies to assess p-AKT, ChAT, p-PERK, p-eIF-2a, p-c-Jun, and N terminus ATF6 are also listed in Table 1.…”

Section: Methodsmentioning

confidence: 99%