Development and evaluation of a non-invasive brain-spine interface using transcutaneous spinal cord stimulation.

Motor rehabilitation is a therapeutic process to facilitate functional recovery in people with spinal cord injury (SCI). However, its efficacy is limited to areas with remaining sensorimotor function. Spinal cord stimulation (SCS) creates a temporary prosthetic effect that may allow further rehabilitation-induced recovery in individuals without remaining sensorimotor function, thereby extending the therapeutic reach of motor rehabilitation to individuals with more severe injuries.

FUNDAMENTAL LIMITATIONS OF KILOHERTZ-FREQUENCY CARRIERS IN AFFERENT FIBER RECRUITMENT WITH TRANSCUTANEOUS SPINAL CORD STIMULATION.

The use of kilohertz-frequency (KHF) waveforms has rapidly gained momentum in transcutaneous spinal cord stimulation (tSCS) to restore motor function after paralysis. However, the mechanisms by which these fast-alternating currents depolarize efferent and afferent fibers remain unknown. Our study fills this research gap by providing a hypothesis-and evidence-based investigation using peripheral nerve stimulation, lumbar tSCS, and cervical tSCS in 25 unimpaired participants together with computational modeling.

Novel Assessment of the Impact of Irritability on Physiological and Psychological Frustration Responses in Adolescents.

Objective: Irritability, typically defined as a proneness to anger, particularly in response to frustration, falls at the intersection of emotion and disruptive behavior. Despite well-defined translational models, there are few convergent findings regarding the pathophysiology of irritability. Most studies utilize computer-based tasks to examine neural responses to frustration, with little work examining stress-related responding to frustration in social contexts.

Enhanced selectivity of transcutaneous spinal cord stimulation by multielectrode configuration.

Transcutaneous spinal cord stimulation (tSCS) has been gaining momentum as a non-invasive rehabilitation approach to restore movement to paralyzed muscles after spinal cord injury (SCI). However, its low selectivity limits the types of movements that can be enabled and, thus, its potential applications in rehabilitation.In this cross-over study design, we investigated whether muscle recruitment selectivity of individual muscles could be enhanced by multielectrode configurations of tSCS in 16 neurologically intact individuals.

Enhanced selectivity of transcutaneous spinal cord stimulation by multielectrode configuration.

Objective: Transcutaneous spinal cord stimulation (tSCS) has been gaining momentum as a non-invasive rehabilitation approach to restore movement to paralyzed muscles after spinal cord injury (SCI). However, its low selectivity limits the types of movements that can be enabled and, thus, its potential applications in rehabilitation.

Approach: In this cross-over study design, we investigated whether muscle recruitment selectivity of individual muscles could be enhanced by multielectrode configurations of tSCS in 16 neurologically intact individuals.

Sidekick: A Low-Cost Open-Source 3D-printed liquid dispensing robot.

The Sidekick is a desktop liquid dispenser, compatible with standard SBS microplates and designed for accessible laboratory automation. It features an armature-based motion system and a fully 3D-printed chassis to reduce overall mechanical complexity and accommodate user modification. Liquid dispensing is achieved with four commercially available solenoid driven positive displacement pumps that deliver liquid in 10 µL increments.

Importance ratings on patient-reported outcome items for survivorship care: comparison between pediatric cancer survivors, parents, and clinicians.

Purpose: To compare importance ratings of patient-reported outcomes (PROs) items from the viewpoints of childhood cancer survivors, parents, and clinicians for further developing short-forms to use in survivorship care.

Methods: 101 cancer survivors, 101 their parents, and 36 clinicians were recruited from St. Jude Children's Research Hospital.

Glutamatergic and morphological alterations associated with early life seizure-induced preconditioning in young rats.

Postnatal day (P)20 rats are sensitive to CA1 injury following a single injection of kainic acid (KA) but are resistant to this injury when animals have a history of two neonatal seizures. We hypothesized that the two earlier seizures led to neuroprotection by a preconditioning mechanism. Therefore, morphology, [Ca(2+)](i) and NMDA subunit proteins of the hippocampus were examined after KA was administered once (1 × KA, on P6, P9, P13 or P20), twice (2 × KA, on P6 and P9) or three times (3 × KA, on P6, P9, P13 or P20).

Age- and region-dependent patterns of Ca2+ accumulations following status epilepticus.

Elevated Ca(2+) concentrations have been implicated in cell death mechanisms following seizures, however, the age and brain region of intracellular Ca(2+) accumulations [Ca(2+)](i), may influence whether or not they are toxic. Therefore, we examined regional accumulations of (45)Ca(2+) by autoradiography from rats of several developmental stages (P14, P21, P30 and P60) at 5, 14, and 24h after status epilepticus. To determine whether the uptake was intracellular, Ca(2+) was also assessed in hippocampal slices with the dye indicator, Fura 2AM at P14.

Body energy homeostasis.

Evidence for the regulation of body energy is reviewed from the homeostatic perspective of Claude Bernard and Walter Cannon. The complementary roles of food intake and energy expenditure in the maintenance and defense of energy balance are considered. Particular attention is paid to the roles adjustments in energy expenditure play in this process and to recent investigations identifying their metabolic underpinnings.

NR1 knockdown reveals CA1 injury during a developmental period of high seizure susceptibility despite reduced seizure activity.

NMDA receptors (NMDARs) are important for the propagation of seizures. To understand the role of NR1 subunits in the propagation of seizures we knocked down the NR1 subunit by intracranial injection of antisense deoxyoligonucleotides (NR1-AS-ODNs) into the right hippocampus during a window of maximal seizure susceptibility in development. Control missense and sense ODNs followed by focal injection of NMDA (2.

Ligand--protein interactions in the glutamate receptor.

Fourier transform infrared spectroscopy was used to investigate ligand-protein interactions in the ligand-binding domain of the GluR4 glutamate receptor subunit. Glutamate binding induces more extensive secondary structural changes in the ligand-binding domain than does kainate binding. Glutamate also alters the hydrogen bonding strength of the single free cysteine side chain in the domain, while kainate does not.

Growth hormone, insulin-like growth factor-1, and the insulin-like growth factor binding proteins in rats maintaining reduced body protein following lesions of the lateral hypothalamus.

Rats with lesions of the lateral hypothalamus (LH) maintain a reduced body protein mass that they effectively defend when challenged by under- or over-nutrition. The two studies reported here evaluate the potential contributions of growth hormone (GH), insulin-like growth factor-1 (IGF-1), and the insulin-like growth factor-binding (IGFBP) to this persistent maintenance of a reduced body protein mass by LH rats. At 18 weeks postlesion, it was found that the serum levels of GH, IGF-1, total IGFBP, and IGFBP-3 of LH rats maintaining reduced body protein were not different from those of age-matched controls.

Use of evolutionary factor analysis in the spectroelectrochemistry of Escherichia coli sulfite reductase hemoprotein and a Mo/Fe/S cluster.

The deconvolution of spectroelectrochemical data is often quite difficult if the spectra of intermediates are not known. Factor analysis, however, has been shown to be a powerful technique which can make it possible to deconvolute overlapping spectra. In this work, evolving factor analysis will be used to determine the number of intermediates and the spectra of those species for two typical spectroelectrochemical experiments: linear scan voltammetry and chronoabsorptometry in a thin-layer cell.

Defense of differing body weight set points in diet-induced obese and resistant rats.

Among outbred Sprague-Dawley rats, approximately one-half develop diet-induced obesity (DIO) and one-half are diet resistant (DR) on a diet relatively high in fat and energy content (HE diet). Here we examined the defense of body weight in these two phenotypes. After HE diet for 13 wk, followed by chow for 6 wk, DR rats gained weight comparably but their plasma leptin levels fell to 54% of chow-fed controls.

Body weight set-points: determination and adjustment.

It is proposed that body weight, like body water and body temperature, is physiologically regulated. In the case of body weight, coordinated adjustments in both the intake and expenditure of energy serve to stabilize the weights of individuals at a specified level and to resist their displacement from this level. Obese individuals also display these behavioral and metabolic adjustments to weight perturbations and thus appear to actively resist efforts to reduce their weight from the elevated levels they ordinarily display.

Selective breeding for diet-induced obesity and resistance in Sprague-Dawley rats.

In outbred Sprague-Dawley rats, about one-half develop diet-induced obesity (DIO) on a diet relatively high in fat and energy (HE diet). The rest are diet resistant (DR), gaining weight and fat at the same rate as chow-fed controls. Here we selectively bred for high (DIO) and low (DR) weight gainers after 2 wk on HE diet.

Growth hormone or insulin-like growth factor I increases fat oxidation and decreases protein oxidation without altering energy expenditure in parenterally fed rats.

We assessed whether the increased growth in parenterally fed rats treated with growth hormone (GH) or insulin-like growth factor I (IGF-I) or both is associated with alterations in energy expenditure or macronutrient oxidation or both. Surgically stressed male rats (approximately 235 g) were given total parenteral nutrition (TPN) and treated with recombinant human GH (rhGH) (800 micrograms/d), rhIGF-I (800 micrograms/d), rhGH+rhIGF-I (800 micrograms/d of each), or TPN alone for 3 d. Treatment with GH or IGF-I or both resulted in significantly greater body weight gain, nitrogen retention, and serum total IGF-I concentrations compared with TPN alone (P < 0.

The specific locus and time course of the body protein adjustments produced in rats by lesions of the lateral hypothalamus.

Lesions of the lateral hypothalamus (LH) result in a body weight reduction characterized by declines in both lean and adipose tissues. The body fat of LH-lesioned rats can be restored to or above the levels of nonlesioned rats by overfeeding. However, the protein deficit cannot be so reversed, suggesting that the lesion-induced body protein reduction is chronic.

Chronically altered body protein levels following lateral hypothalamic lesions in rats.

Rats maintaining reduced body weights after lesions of the lateral hypothalamus (LH; LH rats) are characterized by smaller body protein masses. Two experiments were conducted to determine whether this reduced protein mass is actively defended. In the first, it was found that LH rats induced to overeat and restore body weight to the level of nonlesioned controls markedly increased their body fat without significantly increasing body protein.

Body energy status and the metabolic response to acute inflammation.

An animal model of acute inflammation was used to examine how body energy status influences the syndrome of anorexia, negative nitrogen balance, and body weight loss typically seen in response to injury. Specifically, the metabolic response to acute inflammation was studied in rats of normal, elevated, or reduced body weights. Rats induced to overeat and gain weight prior to inflammation displayed protracted anorexia, greater subsequent weight loss, higher metabolic rates, and greater negative energy balance than rats of normal weight.

Fever and the acute elevation in whole-body thermogenesis induced by lateral hypothalamic lesions.

Three studies investigated the role of fever in the acute elevation of heat production induced by lateral hypothalamic (LH) lesions and the mechanisms by which this thermogenic response can be attenuated by reductions in body weight. In Study 1, reducing the weights of rats prior to lesioning the LH attenuated both the usual postlesion fever and elevation in thermogenesis. In Study 2, blocking prostaglandin synthesis with indomethacin likewise blunted both the lesion-induced fever and thermogenesis.

Changes in body composition and daily energy expenditure induced in rats during eight weeks of daily swim training.

The body weight, body composition, and daily (post-exercise) energy expenditure of five groups of male rats were examined following 1, 2, 4, 6 or 8 weeks of daily (1 h) swim training. Rats that swam daily weighed less than sedentary controls and had smaller adipose and lean tissue masses. The size of these body weight and composition changes grew as daily training progressed.

Energy expenditure in rats maintained with intravenous or intragastric infusion of total parenteral nutrition solutions containing medium- or long-chain triglyceride emulsions.

Energy expenditure was determined in male Fischer 344 rats (235-246 g) fed by intravenous (IV) or intragastric (IG) infusion with total parenteral nutrition solutions providing 65% of nonprotein energy as fat from long-chain triglyceride (LCT) or a 3:1 admixture of medium-chain triglyceride (MCT) and LCT emulsions. Respiratory gas exchange and somatomotor activity were assessed continuously for 24 h during d 5 and 11 of infusion feeding. The MCT infusion resulted in one-third the weight gain noted with LCT infusion (MCT, 10 +/- 2 g/14 d; LCT, 32 +/- 4 g/14 d; P less than 0.

Nicotine effects on body weight: a regulatory perspective.

Rats infused with nicotine were initially hypophagic and lost weight. Although food intake recovered, body weight remained 8-12% below normal. Elevating (or reducing) body weight before treatment prolonged (or shortened) initial hypophagia; weight reliably stabilized at the reduced level.