Skip to main content
Fig. 2 | Acta Neuropathologica Communications

Fig. 2

From: Impaired signaling for neuromuscular synaptic maintenance is a feature of Motor Neuron Disease

Fig. 2

Muscle denervation-reinnervation and NMJ disassembly is evident in MND patients. A Maximum projection images of individual NMJs from non-MND and MND muscle biopsies. Motor endplates from four non-MND patients (Con-1, -2, -3 and -4) displayed presynaptic motor terminal endings (red bulbous structures), surrounded by dense clusters of postsynaptic AChRs (green halos, white arrows). NMJs from three MND patients (MND-2, -3 and -4) display varying stages of disassembly indicated by a reduced density or complete loss of postsynaptic AChR clusters that normally surround the nerve terminal endings (single arrows); shrinkage of nerve terminal relative to AChR cluster area (double arrows); terminal axonal thinning and sprouting (black arrow and lightning bolt respectively). NF-SNP = neurofilament and synaptophysin immuno-stain; AChR = 488 Alexa α-bungarotoxin stain. Scale bars = 10 µm. B Transmission electron micrograph of an NMJ from a non-MND subject (Con-4) displays the motor nerve terminal filled with synaptic vesicles (blue arrows), intact mitochondria (yellow arrow), and a terminal Schwann cell (green and pink arrows in all panels) demarcating the pre- and postsynaptic membrane apposition. Deep infoldings of the opposing postsynaptic muscle membrane (postsynaptic junctional folds) contain basal lamina (red arrows in all panels). NMJs from MND-3 (middle panel) shows motor terminal and a flattened motor endplate, with no overlying nerve terminal (black arrow), and signs of damaged mitochondria within the terminal ending (yellow arrow). Right panel reveals terminal Schwann cell invasion into the synaptic cleft (green and arrows)

Back to article page