We recorded motor-evoked potentials (MEPs) from relaxed hand and leg muscles of healthy subjects who were reading silently hand- or leg-related action, sensorial (non-somatic) and abstract verbs conjugated either in future or past tense. The amplitude of MEPs recorded from the hand was higher during reading hand-related action verbs conjugated in
the future than in the past. No future-related modulation of leg muscles activity was found during reading leg-related action verbs. In a similar vein, no future-related change of hand selleck chemical or leg muscles reactivity was found for abstract or sensorial verbs. These results indicate that the anticipatory mirroring of hand actions may be triggered by linguistic representations and not only by direct action observation. “
“Understanding brain reorganization following long-term spinal cord injuries is important for optimizing recoveries based on residual see more function as well as developing brain-controlled assistive devices. Although it has been shown that the motor cortex undergoes partial reorganization within a few weeks after peripheral and spinal cord injuries, it is not known if the motor cortex of rats is capable of large-scale reorganization after longer recovery periods. Here we determined
the organization of the rat (Rattus norvegicus) motor cortex at 5 or more months after chronic lesions of the spinal cord at cervical levels using intracortical microstimulation. The results show that, in the rats with the lesions, stimulation of neurons in the de-efferented forelimb motor cortex no longer evokes movements of the forelimb. Instead, movements of the body parts in the adjacent representations, namely the whiskers and neck were evoked. In addition, at many sites, movements of the ipsilateral forelimb were observed at threshold currents. The extent of representations of the eye,
jaw and tongue movements was unaltered by the lesion. Thus, large-scale reorganization of the motor cortex leads to complete filling-in of the de-efferented cortex by neighboring representations following long-term partial spinal cord injuries at cervical levels in adult rats. “
“Oligodendrocytes are the myelin-forming cells of the central nervous system that facilitate transmission of axonal electrical impulses. Using transgenic mice Baricitinib expressing 2′,3′ cyclic nucleotide 3′ phosphodiesterase (CNPase)-enhanced green fluorescent protein, a three-dimensional reconstruction tool and analysis, we illustrate that three morphologically different oligodendrocyte types exist in the hippocampus. Those of the ramified type have the most numerous processes, the largest cell body, occupy the largest area and form beaded-like structures, due to mitochondria aggregates, along the processes. Stellar-shaped oligodendrocytes have smaller cell bodies and their processes cover a significantly smaller area. Those of the smooth subtype have a small cell body with at most two processes.