Trophic regulation of nerve cell morphology and innervation in the autonomic nervous system

Purves, Dale; Snider, William D.; Voyvodic, James T.

doi:10.1038/336123a0

Cited by 329 publications

(171 citation statements)

References 33 publications

Supporting

Mentioning

164

Contrasting

Unclassified

Order By: Relevance

“…At the very beginning, calcium homeostasis disturbances 9 and trophic factor withdrawal 10 occurs after axotomy and participate in this neuronal response. Both events had already been linked to ER stress in vitro.…”

Section: Discussionmentioning

confidence: 99%

“…The lack of these trophic factors in turn initiates the cell responses of neurons and surrounding glial after axotomy. 10 The endoplasmic reticulum (ER) is a dynamic network of interconnected membrane tubules that essentially reaches every part of the cell, including dendrites 11 and axons 12 in neurons. ER is associated with microtubules 13 and largely contributes to local calcium homeostasis and signaling, and protein and lipid biosynthesis.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Autophagy, and BiP level decrease are early key events in retrograde degeneration of motoneurons

et al. 2011

View full text Add to dashboard Cite

Disconnection of the axon from the soma of spinal motoneurons (MNs) leads either to a retrograde degenerative process or to a regenerative reaction, depending on the severity and the proximity to the soma of the axonal lesion. The endoplasmic reticulum (ER) is a continuous membranous network that extends from the nucleus to the entire cytoplasm of the neuronal soma, axon and dendrites. We investigated whether axonal injury is sensed by the ER and triggers the activation of protective mechanisms, such as the unfolded protein response (UPR) and autophagy. We found early (at 3 days) accumulation of beclin1, LC3II and Lamp-1, hallmarks of autophagy, in both degenerating MNs after spinal root avulsion and in non-degenerating MNs after distal nerve section, although Lamp-1 disappeared by 5 days only in the former. In contrast, only degenerating MNs presented early activation of IRE1a, revealed by an increase of the spliced isoform of Xbp1 and accumulation of ATF4 in their nucleus, two branches of the UPR, and late BiP downregulation in association with cytoskeletal and organelle disorganization. We conclude that BiP decrease is a signature of the degenerating process, as its overexpression led to an increase in MN survival after root avulsion. Besides, Bcl2 is strongly implicated in the survival pathway activated by BiP overexpression.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Autophagy, and BiP level decrease are early key events in retrograde degeneration of motoneurons

et al. 2011

View full text Add to dashboard Cite

show abstract

“…In this study, we examined the role of the ERK pathway in the regulation of dendritic growth in sympathetic neurons exposed to BMP-7 and NGF. Costimulation with these two agents leads to a rate of dendritic growth in vitro that is equivalent to that observed in vivo (Lein et al, 1995), and there is evidence for sympathetic neurons being exposed to both of these growth factors in vivo, with NGF being derived from target tissues (Purves et al, 1988) and BMPs being produced by glia .…”

Section: Introductionmentioning

confidence: 95%

Extracellular Signal-Regulated Kinases Regulate Dendritic Growth in Rat Sympathetic Neurons

et al. 2004

View full text Add to dashboard Cite

NGF activates several signaling cascades in sympathetic neurons. We examined how activation of one of these cascades, the ERK/MAP (extracellular signal-regulated kinase/mitogen-activated protein) kinase pathway, affects dendritic growth in these cells. Dendritic growth was induced by exposure to NGF and BMP-7 (bone morphogenetic protein-7). Exposure to NGF increased phosphorylation of ERK1/2. Unexpectedly, two MEK (MAP kinase kinase) inhibitors (PD 98059 and U 0126) enhanced dendritic growth, and a ligand, basic FGF, that activates the ERK pathway inhibited the growth of these processes. The enhancement of dendritic growth by PD 98059 was associated with an increase in the number of axo-dendritic synapses, and it appeared to represent a specific morphogenic effect because neither axonal growth nor cell survival was affected. In addition, increased dendritic growth was not observed after exposure to inhibitors of other signaling pathways, including the phosphatidylinositol-3-kinase inhibitor LY 294002. Dendritic growth was also increased in cells transfected with dominant-negative mutants of MEK1 and ERK2 but not with dominant-negative mutants of MEK5 and ERK5, suggesting that ERK1/2 is the primary mediator of this effect. Exposure to BMP-7 induces nuclear translocation of Smad1 (Sma-and Mad-related protein 1), and PD 98059 treatment potentiated nuclear accumulation of Smad-1 induced by BMP-7 in sympathetic neurons, suggesting a direct enhancement of BMP signaling in cells treated with an MEK inhibitor. These observations indicate that one of the signaling cascades activated by NGF can act in an antagonistic manner in sympathetic neurons and reduce the dendritic growth induced by other NGF-sensitive pathways.

show abstract

“…Recent studies have indicated that the initiation of dendrites is, in part, governed by mechanisms intrinsic to neurons (Dotti et al, 1988;Black and Baas, 1989). In addition, there is ample evidence that extrinsic factors influence neuronal polarity and dendritic arborization (Mudge, 1984;Bruckenstein and Higgins, 1988a,b;Purves et al, 1988;Snider, 1988;Tropea et al, 1988;Chamak and Prochiantz, 1989;Johnson et al, 1989;Lein and Higgins, 1989;Clendening and Hume, 1990;&hilling et al, 1991).…”

mentioning

confidence: 99%

NGF induces neonatal rat sensory neurons to extend dendrites in culture after removal of satellite cells

1993

View full text Add to dashboard Cite

Vertebrate sensory neurons have a pseudo-unipolar morphology; their somata are covered by satellite cells and lack dendrites or synaptic contacts. However, when neonatal rat sensory neurons from the nodose ganglia develop in culture in absence of satellite cells and with NGF, they form synapses among themselves. In this study, we investigated whether neonatal rat nodose neurons express dendrites under the same culture conditions. We show by Lucifer yellow injection that nodose neurons remain typically unipolar when cocultured with their ganglionic satellite cells. However, when these neurons are cultured without satellite cells, virtually all neurons acquire a multipolar morphology. Moreover, when NGF is added to satellite cell-free cultures, several neurons extend dendrites; these processes stain positively for microtubule-associated protein-2. NGF induces a 17-fold increase in dendritic outgrowth after 3 weeks but has little effect on axon number. In addition, we find that the ability of nodose neurons to extend dendrites is developmentally regulated. Furthermore, in a combined morphological and electrophysiological study, using whole-cell voltage- clamp technique with Lucifer yellow in the recording solution, we demonstrate a positive correlation between the extent of dendritic outgrowth and the density of ACh currents, suggesting that these dendrites have ACh receptors. Our results indicate that neonatal rat nodose neurons are capable of extending dendrites and that extrinsic factors can induce or suppress their extension. In addition, the results suggest that these dendrites may act as principal post-synaptic structures for synapse formation that occurs in these cultures.

show abstract

Trophic regulation of nerve cell morphology and innervation in the autonomic nervous system

Cited by 329 publications

References 33 publications

Autophagy, and BiP level decrease are early key events in retrograde degeneration of motoneurons

Autophagy, and BiP level decrease are early key events in retrograde degeneration of motoneurons

Extracellular Signal-Regulated Kinases Regulate Dendritic Growth in Rat Sympathetic Neurons

NGF induces neonatal rat sensory neurons to extend dendrites in culture after removal of satellite cells

Contact Info

Product

Resources

About