The pattern of remyelination after traumatic spinal cord injury remains elusive, with animal and human studies reporting partial to complete demyelination followed by incomplete remyelination. In the present study, we found that spared rubrospinal tract (RST) axons passage traced actively transported dextrans examined caudally lesion 12 weeks mouse contusion were fully remyelinated. Spared exhibited a marginally reduced myelin thickness significantly shorter internodes. CASPR...

The Neurochip-2 is a second generation, battery-powered device for neural recording and stimulating that small enough to be carried in chamber on monkey's head. It has three channels, with user-adjustable gains, filters, sampling rates, can optimized single unit activity, local field potentials, electrocorticography, electromyography, arm acceleration, etc. Recorded data are stored removable, flash memory card. also separate stimulation channels. Two "programmable-system-on-chips" (PSoCs)...

We report the first neural recording during ecstatic meditations called jhanas and test whether a brain reward system plays role in joy reported. Jhanas are Altered States of Consciousness (ASC) that imply major changes based on subjective reports: (1) external awareness dims, (2) internal verbalizations fade, (3) sense personal boundaries is altered, (4) attention highly focused object meditation, (5) increases to high levels. The fMRI EEG results from an experienced meditator show activity...

Remyelination following spinal cord injury (SCI) is thought to be incomplete; demyelination reported persist chronically and proposed as a compelling therapeutic target. Yet most reports do not distinguish between the myelin status of intact axons injury-severed whose proximal stumps but provide no meaningful function. We previously found full remyelination spared, rubrospinal caudal lesion in chronic mouse SCI. However, clinical concept demyelinated spared remains controversial. Since...

Abstract We describe an integrate-and-fire (IF) spiking neural network that incorporates spike-timing-dependent plasticity (STDP) and simulates the experimental outcomes of four different conditioning protocols produce cortical plasticity. The original experiments were performed in freely moving non-human primates (NHPs) with autonomous head-fixed bidirectional brain-computer interface (BCI). Three involved closed-loop stimulation triggered from (1) spike activity single neurons, (2)...

Toward addressing many neuroprosthetic applications, the Neurochip3 (NC3) is a multichannel bidirectional brain-computer interface that operates autonomously and can support closed-loop activity-dependent stimulation. It consists of four circuit boards populated with off-the-shelf components sufficiently compact to be carried on head non-human primate (NHP). NC3 has six main components: (1) an analog front-end Intan biophysical signal amplifier (16 differential or 32 single-ended channels)...

In monkeys performing a step-tracking task, the discharge patterns of forearm motor units and connected premotoneuronal cells in cortex red nucleus (identified by postspike facilitation EMG) fall into characteristic classes: tonic, phasic-tonic, decrementing, etc. The authors used dynamic neural network models incorporating these to investigate networks that could transform step input target position observed flexor extensor motoneurons. These have interconnected hidden with either...

Vagus nerve stimulation (VNS) has been tested as therapy for several brain disorders and a means to modulate cortical excitability plasticity. Cortical effects of VNS, manifesting vagal-evoked potentials (VEPs), are thought arise from activation ascending cholinergic noradrenergic systems. However, it is unknown whether those modulated by state at the time stimulation. In 2 freely behaving macaque monkeys, we delivered short trains 5 pulses left cervical vagus different frequencies (5-300...

Abstract Background Computational models that predict effects of neural stimulation can be used as a preliminary tool to inform in-vivo research, reducing the costs, time, and ethical considerations involved. However, current do not support diverse techniques , including expanding selection electrodes, modalities, paradigms. New Method To develop more comprehensive software, we created several extensions The Virtual Electrode Recording Tool for EXtracellular Potentials (VERTEX), MATLAB-based...

Abstract The activity and connectivity of neurons in the primate brain underlying behavior cannot yet be completely specified, but neural networks provide complete models that performs specific tasks insight into computations performed by (Fetz Shupe 2003). Studies monkey cortex have shown short-term memory sensory events may mediated sustained activity. Short-term been modeled with dynamic using a single continuous variable gate input to create sample-and-hold (SAH) function (Zipser 1991;...

Abstract Synchrony of oscillatory brain activity has been postulated to be a binding mechanism for cognitive and motor functions. Spectral analysis human electrocorticogram (ECoG) in sensorimotor cortex shown that power density gamma band (30-60 Hz) increased alpha-beta (10-20 decreased during performance manipulative visuomotor tasks, indicating amplitude modulation the occurred relation task performance. Amplitude may provide evidence synchrony local neuronal assembly. However, it does not...

Dynamic neural networks with recurrent connections were trained by backpropagation to generate the differential or leaky integral of a nonrepeating frequency-modulated sinusoidal signal. The performed these operations on arbitrary input waveforms. Reducing network size deleting ineffective hidden units and combining redundant units, then retraining produced minimal that computed same function revealed underlying computational algorithm. Networks could also be compute simultaneously two...

Summary form only given, as follows. Dynamic neural networks with recurrent connections were trained by backpropagation to generate the differential or leaky integral of a nonrepeating frequency-modulated sinusoidal signal. The performed these operations on arbitrary test inputs. Reducing network size deleting and combining hidden units then retraining produced smaller that computed same function revealed underlying computational algorithm. Networks could also be compute simultaneously input...

Abstract We describe an integrate-and-fire (IF) spiking neural network that incorporates spike-timing dependent plasticity (STDP) and simulates the experimental outcomes of four different conditioning protocols produce cortical plasticity. The original experiments were performed in freely moving non-human primates with autonomous head-fixed bidirectional brain-computer interface. Three involved closed-loop stimulation triggered from (a) spike activity single neurons, (b) EMG forearm muscles,...

Abstract Vagus nerve stimulation (VNS) has been tested as therapy for several brain disorders and a means to modulate cortical excitability plasticity. Cortical effects of VNS, manifesting vagal-evoked potentials (VEPs), are thought arise from activation ascending cholinergic noradrenergic systems. However, it is unknown whether those modulated by state at the time stimulation. In 2 freely behaving macaque monkeys, we delivered trains left cervical VNS different frequencies (5-300 Hz) while...