The role of perisynaptic Schwann cells in development of neuromuscular junctions in the frog (xenopus laevis)

Reciprocal interactions between perisynaptic Schwann cells and regenerating nerve terminals at the frog neuromuscular junction

“…As observed previously (Astrow et al, 1998), FM 4-64 labels all NT branches at the intact frog NMJ. Furthermore, we find a close match between FM 4-64 and ␣-BTX at developing frog (Xenopus laevis) NMJs (Herrera et al, 1998), suggesting that FM 4-64 labels fine, developing NT processes. FM 4-64 and FM 1-43 have also been used to label synaptic boutons during synaptogenesis in hippocampal neuronal cultures (Ziv and Smith, 1996), and neurites making initial neuromuscular contacts in nerve-muscle cultures (Dai and Peng, 1998).…”

“…To visualize the dynamic relationship between PSCs and regenerating NTs after nerve injury, identified frog NMJs were imaged in vivo using PNA, which labels the extracellular matrix associated with PSCs (Ko, 1987;Chen et al, 1991), and the fluorescent dye, FM 4-64, which, similar to FM 1-43 (Betz et al, 1992), labels recycled synaptic vesicles in living NTs. In a previous study (Herrera et al, 1998), we showed FM 4-64-labeled NTs apposed to AChR patches at developing NMJs. FM 1-43 and FM 4-64 have also been used to label presynaptic terminals during synaptogenesis in vitro (Ziv and Smith, 1996;Dai and Peng, 1998).…”

Reciprocal interactions between perisynaptic Schwann cells and regenerating nerve terminals at the frog neuromuscular junction

“…As observed previously (Astrow et al, 1998), FM 4-64 labels all NT branches at the intact frog NMJ. Furthermore, we find a close match between FM 4-64 and ␣-BTX at developing frog (Xenopus laevis) NMJs (Herrera et al, 1998), suggesting that FM 4-64 labels fine, developing NT processes. FM 4-64 and FM 1-43 have also been used to label synaptic boutons during synaptogenesis in hippocampal neuronal cultures (Ziv and Smith, 1996), and neurites making initial neuromuscular contacts in nerve-muscle cultures (Dai and Peng, 1998).…”

“…To visualize the dynamic relationship between PSCs and regenerating NTs after nerve injury, identified frog NMJs were imaged in vivo using PNA, which labels the extracellular matrix associated with PSCs (Ko, 1987;Chen et al, 1991), and the fluorescent dye, FM 4-64, which, similar to FM 1-43 (Betz et al, 1992), labels recycled synaptic vesicles in living NTs. In a previous study (Herrera et al, 1998), we showed FM 4-64-labeled NTs apposed to AChR patches at developing NMJs. FM 1-43 and FM 4-64 have also been used to label presynaptic terminals during synaptogenesis in vitro (Ziv and Smith, 1996;Dai and Peng, 1998).…”

Schwann Cells Express Active Agrin and Enhance Aggregation of Acetylcholine Receptors on Muscle Fibers

“…The absence of active agrin expression in tadpole Schwann cells also indicates that Schwann cell-derived agrin is unlikely to play a role in the aggregation of AChRs during initial synaptogenesis. Consistent with this view, there is no AChR clustering along Schwann cell sprouts that extend beyond developing nerve terminals during synapse formation in tadpole muscles (Herrera et al, 2000). This is in contrast to adult muscles, in which aggregates of AChRs are formed along PSC sprouts after nerve injury and reinnervation (see below).…”

Clinical relevance of terminal Schwann cells: An overlooked component of the neuromuscular junction

“…Single tSCs have also been shown to decipher the strength of individual synaptic activity during synaptic competition and influence synaptic elimination (Darabid et al 2013). Synaptic elimination has been noted to occur at the period of greatest tSC occupation at the NMJ in amphibians (Herrera et al 2000) and mammals (Love and Thompson 1998) A recent study supports these findings and suggests that tSC phagocytic roles are induced by neuronal expression of Neuregulin1 (Lee et al 2016).…”

Reciprocal interactions between perisynaptic Schwann cells and regenerating nerve terminals at the frog neuromuscular junction

“…As observed previously (Astrow et al, 1998), FM 4-64 labels all NT branches at the intact frog NMJ. Furthermore, we find a close match between FM 4-64 and ␣-BTX at developing frog (Xenopus laevis) NMJs (Herrera et al, 1998), suggesting that FM 4-64 labels fine, developing NT processes. FM 4-64 and FM 1-43 have also been used to label synaptic boutons during synaptogenesis in hippocampal neuronal cultures (Ziv and Smith, 1996), and neurites making initial neuromuscular contacts in nerve-muscle cultures (Dai and Peng, 1998).…”

“…To visualize the dynamic relationship between PSCs and regenerating NTs after nerve injury, identified frog NMJs were imaged in vivo using PNA, which labels the extracellular matrix associated with PSCs (Ko, 1987;Chen et al, 1991), and the fluorescent dye, FM 4-64, which, similar to FM 1-43 (Betz et al, 1992), labels recycled synaptic vesicles in living NTs. In a previous study (Herrera et al, 1998), we showed FM 4-64-labeled NTs apposed to AChR patches at developing NMJs. FM 1-43 and FM 4-64 have also been used to label presynaptic terminals during synaptogenesis in vitro (Ziv and Smith, 1996;Dai and Peng, 1998).…”

Schwann Cells Express Active Agrin and Enhance Aggregation of Acetylcholine Receptors on Muscle Fibers

“…The absence of active agrin expression in tadpole Schwann cells also indicates that Schwann cell-derived agrin is unlikely to play a role in the aggregation of AChRs during initial synaptogenesis. Consistent with this view, there is no AChR clustering along Schwann cell sprouts that extend beyond developing nerve terminals during synapse formation in tadpole muscles (Herrera et al, 2000). This is in contrast to adult muscles, in which aggregates of AChRs are formed along PSC sprouts after nerve injury and reinnervation (see below).…”

Clinical relevance of terminal Schwann cells: An overlooked component of the neuromuscular junction

“…Single tSCs have also been shown to decipher the strength of individual synaptic activity during synaptic competition and influence synaptic elimination (Darabid et al 2013). Synaptic elimination has been noted to occur at the period of greatest tSC occupation at the NMJ in amphibians (Herrera et al 2000) and mammals (Love and Thompson 1998) A recent study supports these findings and suggests that tSC phagocytic roles are induced by neuronal expression of Neuregulin1 (Lee et al 2016).…”

Reciprocal interactions between perisynaptic Schwann cells and regenerating nerve terminals at the frog neuromuscular junction

“…As observed previously (Astrow et al, 1998), FM 4-64 labels all NT branches at the intact frog NMJ. Furthermore, we find a close match between FM 4-64 and ␣-BTX at developing frog (Xenopus laevis) NMJs (Herrera et al, 1998), suggesting that FM 4-64 labels fine, developing NT processes. FM 4-64 and FM 1-43 have also been used to label synaptic boutons during synaptogenesis in hippocampal neuronal cultures (Ziv and Smith, 1996), and neurites making initial neuromuscular contacts in nerve-muscle cultures (Dai and Peng, 1998).…”

“…To visualize the dynamic relationship between PSCs and regenerating NTs after nerve injury, identified frog NMJs were imaged in vivo using PNA, which labels the extracellular matrix associated with PSCs (Ko, 1987;Chen et al, 1991), and the fluorescent dye, FM 4-64, which, similar to FM 1-43 (Betz et al, 1992), labels recycled synaptic vesicles in living NTs. In a previous study (Herrera et al, 1998), we showed FM 4-64-labeled NTs apposed to AChR patches at developing NMJs. FM 1-43 and FM 4-64 have also been used to label presynaptic terminals during synaptogenesis in vitro (Ziv and Smith, 1996;Dai and Peng, 1998).…”

Schwann Cells Express Active Agrin and Enhance Aggregation of Acetylcholine Receptors on Muscle Fibers

“…The absence of active agrin expression in tadpole Schwann cells also indicates that Schwann cell-derived agrin is unlikely to play a role in the aggregation of AChRs during initial synaptogenesis. Consistent with this view, there is no AChR clustering along Schwann cell sprouts that extend beyond developing nerve terminals during synapse formation in tadpole muscles (Herrera et al, 2000). This is in contrast to adult muscles, in which aggregates of AChRs are formed along PSC sprouts after nerve injury and reinnervation (see below).…”

Clinical relevance of terminal Schwann cells: An overlooked component of the neuromuscular junction

“…Single tSCs have also been shown to decipher the strength of individual synaptic activity during synaptic competition and influence synaptic elimination (Darabid et al 2013). Synaptic elimination has been noted to occur at the period of greatest tSC occupation at the NMJ in amphibians (Herrera et al 2000) and mammals (Love and Thompson 1998) A recent study supports these findings and suggests that tSC phagocytic roles are induced by neuronal expression of Neuregulin1 (Lee et al 2016).…”