Low levels of the survival motor neuron protein (SMN) cause the disease spinal muscular atrophy. A primary characteristic of this disease is motoneuron dysfunction and paralysis. Understanding why motoneurons are affected by low levels of SMN will lend insight into this disease and to motoneuron biology in general. Motoneurons in zebrafish smn mutants develop abnormally; however, it is unclear ...

Approximately half of the motoneurons generated during normal embryonic development undergo programmed cell death. Most of this death occurs during the time when synaptic connections are being formed between motoneurons and their target, skeletal muscle. Subsequent muscle activity stemming from this connection helps determine the final number of surviving motoneurons. These observations have gi...

Chick sensory neurons grow to their correct targets in the hindlimb from the outset during normal development and following various experimental manipulations. This may result not because sensory neurons respond to specific limb-derived cues, but because they interact in some way with motoneurons which are responsive to such cues. To test this possibility, we removed the ventral part of the neu...

The branching structure of the stem dendrites of five motoneurons innervating the dorsal neck muscles, biventer cervicis and complexus, was examined in the adult cat using intracellular staining techniques. The dendritic tree of each motoneuron was reconstructed completely and then dissected into several parts, each corresponding to the branches. Twenty-five of the 49 stem dendrites examined ha...

Similar to mammalian neural progenitors, Drosophila neuroblasts progressively lose competence to make early-born neurons. In neuroblast 7-1 (NB7-1), Kruppel (Kr) specifies the third-born U3 motoneuron and Kr misexpression induces ectopic U3 cells. However, competence to generate U3 cells is limited to early divisions, when the Eve(+) U motoneurons are produced, and competence is lost when NB7-1...

Spinal motoneurons innervating skeletal muscle were amongst the first neurons shown to require the presence of their target cells to develop appropriately. Isolated embryonic chick and rat motoneurons have been used to identify neurotrophic factors and cytokines capable of supporting the survival of developing motoneurons. Such factors include ciliary neurotrophic factor (CNTF), which is presen...

introduction : there are different applications for cooling in rehabilitation and there is also a controversy in results of applying ice on limb and its effects on motorneurons excitability. methods : this study was done to determine the effect of applying controlled cooling (rubbing cold ointment with 3°c temperature) on the spinal skin (around t place of s root nerve) on the excitability of s...

Gonzalez, Michael and William F. Collins, III. Modulation of whereas Type S motoneurons are able to dictate motor unit motoneuron excitability by brain-derived neurotrophic factor. J. contractile speed via an orthodromic mechanism (for review, Neurophysiol. 77: 502–506, 1997. The influence of neurotrophins see Mendell et al. 1994). on motoneuron survival and development has been well docuRecent...

Introduction Several coding stages occur in the nervous system when an internal decision is reached to enact a certain movement. The desired movement is coded into spike trains of a large number of neurons in prefrontal, premotor and suplementary motor cortices as well as in other areas such as the basal ganglia and cerebellum. These spike trains can be assembled in a column vector x(t), each e...