Analysis Tools
nervous system
|
• denervation of the tibialis anterior neuromuscular junctions
|
|
Allele Symbol Allele Name Allele ID |
Mapttm3.1(FUS)Neas targeted mutation 3.1, Neil A Shneider MGI:5776232 |
||||||||||||||||
| Summary |
3 genotypes
|
|
|
| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
|
• denervation of the tibialis anterior neuromuscular junctions
|
|
|
| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
|
• hind-limb weakness; wire hang analysis of P360 mice shows that the average latency to fall is about half that of the controls
|
|
• motor neuron degeneration is associated with astrocytosis and microgliosis
|
|
• motor neuron degeneration is associated with astrocytosis and microgliosis
|
|
• internal nuclei and decreased fiber diameter are seen in the tibialis anterior muscle
• sarcomere length in tibialis anterior muscle is reduced
|
|
• sarcomere length in tibialis anterior muscle is reduced
|
|
• motor neuron degeneration is associated with astrocytosis and microgliosis
|
|
• motor neuron degeneration is associated with astrocytosis and microgliosis
|
|
• by P20, before motor neuron loss, 11.4% of neuromuscular junctions in the tibialis anterior have no associated input, indicating early retraction of motor axons
|
|
• loss of motor neurons at lumber level 5 (L5) is first seen at P30 and progresses steadily to P360
• however, no loss of parvalbumin-positive, proprioceptive sensory neurons in the L5 dorsal root ganglia is seen or of motor neuron loss in oculomotor nucleus at P360
• increase in spontaneous activity in motor neurons, a sign of active denervation of neurogenic origin
|
|
• in the axon terminals of motor neurons, the number of morphologically normal mitochondria is decreased and the remaining mitochondria appear dilated and vacuolated with disorganized cristae and membranes
|
|
• by P20, before motor neuron loss, 11.4% of neuromuscular junctions in the tibialis anterior have no associated input, indicating early retraction of motor axons
• denervation of the gastrocnemius muscle is seen at P90 when about 10% of neuromuscular junctions are vacant
• denervation in both the tibialis anterior and gastrocnemius muscles progresses steadily so that by P360, 36.7% and 19.3% of endplates are vacant in the respective muscles
• by P360, 36.7% and 19.3% of neuromuscular junctions are denervated in the tibialis anterior and gastrocnemius muscles, respectively
• by P360, only 10% of slow soleus muscle motor terminals are vacant
• at P30, neuromuscular junctions (NMJs) show pre-synaptic abnormalities, including a 40% reduction in the density of synaptic vesicles in the pre-synaptic terminals
• however, the number of active zones-the main apparatus for synaptic vesicle release-is unchanged
• in the axon terminals of motor neurons, the number of morphologically normal mitochondria is decreased and the remaining mitochondria appear dilated and vacuolated with disorganized cristae and membranes, while on the postsynaptic side of NMJs, abnormal mitochondria are seen
|
|
• at 50 Hz, a 45% reduction of the motor response amplitude in the tibialis anterior, suggesting that motor neurons cannot sustain reliable neurotransmission at the NMJs and exhibit abnormal synaptic depression
• at 100 Hz, mice exhibit synaptic depression, however the motor response in tibialis anterior motor neurons is often completely absent, indicating failure of neurotransmission
|
|
• motor neurons exhibit abnormal synaptic depression
|
|
• internal nuclei and decreased fiber diameter are seen in the tibialis anterior muscle
• sarcomere length in tibialis anterior muscle is reduced
|
|
|
| ♀ | phenotype observed in females |
| ♂ | phenotype observed in males |
| N | normal phenotype |
|
• mice treated with tamoxifen postnatally show denervation in the tibialis anterior muscle where about 12% of neuromuscular junctions are denervated
|
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO) |
||
|
Citing These Resources Funding Information Warranty Disclaimer, Privacy Notice, Licensing, & Copyright Send questions and comments to User Support. |
last database update 05/07/2024 MGI 6.23 |
|
|
|
||