DNAJB6, a Key Factor in Neuronal Sensitivity to Amyloidogenesis.

CAG-repeat expansions in at least eight different genes cause neurodegeneration. The length of the extended polyglutamine stretches in the corresponding proteins is proportionally related to their aggregation propensity. Although these proteins are ubiquitously expressed, they predominantly cause toxicity to neurons.

Motor unit firing rates during spasms in thenar muscles of spinal cord injured subjects.

Involuntary contractions of paralyzed muscles (spasms) commonly disrupt daily activities and rehabilitation after human spinal cord injury (SCI). Our aim was to examine the recruitment, firing rate modulation, and derecruitment of motor units that underlie spasms of thenar muscles after cervical SCI. Intramuscular electromyographic activity (EMG), surface EMG, and force were recorded during thenar muscle spasms that occurred spontaneously or that were triggered by movement of a shoulder or leg.

Human spinal cord injury: motor unit properties and behaviour.

Spinal cord injury (SCI) results in widespread variation in muscle function. Review of motor unit data shows that changes in the amount and balance of excitatory and inhibitory inputs after SCI alter management of motoneurons. Not only are units recruited up to higher than usual relative forces when SCI leaves few units under voluntary control, the force contribution from recruitment increases due to elevation of twitch/tetanic force ratios.

Corticotropin-releasing factor and urocortin regulate spine and synapse formation: structural basis for stress-induced neuronal remodeling and pathology.

Dendritic spines are important sites of excitatory neurotransmission in the brain with their function determined by their structure and molecular content. Alterations in spine number, morphology and receptor content are a hallmark of many psychiatric disorders, most notably those because of stress. We investigated the role of corticotropin-releasing factor (CRF) stress peptides on the plasticity of spines in the cerebellum, a structure implicated in a host of mental illnesses, particularly of a developmental origin.

Do additional inputs change maximal voluntary motor unit firing rates after spinal cord injury?

Background: Motor unit firing frequencies are low during maximal voluntary contractions (MVCs) of human thenar muscles impaired by cervical spinal cord injury (SCI).

Objective: This study aimed to examine whether thenar motor unit firing frequencies increase when driven by both maximal voluntary drive and other concurrent inputs compared with an MVC alone.

Methods: Motor unit firing rates, force, and surface electromyographic activity (EMG) were compared across 2 contractions: (a) MVC alone and (b) MVC combined with another input (combination contraction).