The , second edition, recommends older adults participate in ≥150 minutes per week of moderate-intensity equivalent aerobic activity and ≥2 days per week of muscle-strengthening activity. We estimated prevalence and trends of meeting the guidelines among US adults aged ≥65 years from 1998 to 2018. Using the 1998-2018 National Health Interview Survey, we estimated the prevalence of meeting aerobic, muscle-strengthening, and combined physical activity guidelines stratified by age group, sex, race and ethnicity, and education level.
View Article and Find Full Text PDFBackground: Assessing awareness and knowledge of the Physical Activity Guidelines for Americans, 2nd edition (Guidelines), released in 2018, is important for monitoring factors that contribute to increasing physical activity.
Methods: We estimated prevalence of awareness and knowledge of the adult aerobic guideline (≥150 min/wk of moderate-intensity equivalent aerobic physical activity preferably spread out over a week) among adults (n = 3471) and of the youth aerobic guideline (≥60 min/d of mostly moderate- to vigorous-intensity aerobic physical activity) among a subset of parents (n = 744) from a nationwide sample of US adults in the 2019 FallStyles survey. We estimated odds ratios using logistic regression, adjusting for demographic and other characteristics.
Recent investments in built environment infrastructure to create healthy communities have highlighted the need for equity and environmental justice. Although the benefits of healthy community design (e.g.
View Article and Find Full Text PDFConnectome-based lesion symptom mapping (CLSM) can be used to relate disruptions of brain network connectivity with clinical measures. We present a novel method that extends current CLSM approaches by introducing a fast reliable and accurate way for computing disconnectomes, i.e.
View Article and Find Full Text PDFTransportation investments have the potential to improve health, but readily available data to guide transportation decisions that could promote health are limited. In October 2015, the U.S.
View Article and Find Full Text PDFSerotonergic (5-HT) and noradrenergic (NA) input to spinal motoneurons is essential for generating plateau potentials and self-sustained discharges. Extensor motoneurons are densely innervated by 5-HT and NA synapses and have robust plateau potentials and self-sustained discharges. Conversely, plateau potentials and self-sustained discharges are very rare in flexor motoneurons.
View Article and Find Full Text PDFBackground: Isolating specific cellular and tissue compartments from 3D image stacks for quantitative distribution analysis is crucial for understanding cellular and tissue physiology under normal and pathological conditions. Current approaches are limited because they are designed to map the distributions of synapses onto the dendrites of stained neurons and/or require specific proprietary software packages for their implementation.
New Method: To overcome these obstacles, we developed algorithms to Grow and Shrink Volumes of Interest (GSVI) to isolate specific cellular and tissue compartments from 3D image stacks for quantitative analysis and incorporated these algorithms into a user-friendly computer program that is open source and downloadable at no cost.
Circadian clocks exhibit 'temperature compensation', meaning that they show only small changes in period over a broad temperature range. Several clock genes have been implicated in the temperature-dependent control of period in Arabidopsis. We show that blue light is essential for this, suggesting that the effects of light and temperature interact or converge upon common targets in the circadian clock.
View Article and Find Full Text PDFThe input-output properties of motoneurons are dynamically regulated. This regulation depends, in part, on the relative location of excitatory and inhibitory synapses, voltage-dependent and -independent channels, and neuromodulatory synapses on the dendritic tree. The goal of the present study was to quantify the number and distribution of synapses from two powerful neuromodulatory systems that originate from noradrenergic (NA) and serotonergic (5-HT) neurons.
View Article and Find Full Text PDFThe Judas technique is a method used for landscape control of feral donkeys (Equus asinus) in northern Australia. Central to the success of any Judas program is the safe, efficient, and humane attachment of the telemetry device. For feral donkeys, this involves the use of field immobilization.
View Article and Find Full Text PDFWe recently reported that some, but not all, axotomized propriospinal commissural interneurons (PCI) of the adult mammal can regenerate through spinal midsagittal transection injury sites (Fenrich and Rose [2009] J Neurosci 29:12145-12158). In this model, regenerating axons grow through a lesion site surrounded by a dense deposition of chondroitin sulfate proteoglycans (CSPG), which are typically inhibitory to regenerating axons. However, the mechanisms that lead some regenerating axons to grow through spinal cord injury (SCI) sites while others remain trapped in the CSPG zones or retract to their soma remain unknown.
View Article and Find Full Text PDFAxotomy can trigger profound alterations in the neuronal polarity of adult neurons in vivo. This can manifest itself in the development of new axon-like processes emanating from the tips of distal dendrites. Previously, these processes have been defined as axonal based on their axonal morphology.
View Article and Find Full Text PDFMutations of SQSTM1 occur in about10% of patients with Paget's disease of bone (PDB), but it is unclear whether they play a causal role or regulate susceptibility to an environmental trigger. Here we show that mice with a proline to leucine mutation at codon 394 of mouse sqstm1 (P394L), equivalent to the P392L SQSTM1 mutation in humans, develop a bone disorder with remarkable similarity to PDB. The P394L mutant mice developed focal bone lesions with increasing age and by 12 months, 14/18 (77%) heterozygotes and 20/21 (95%) homozygotes had lesions, compared with 0/18 (0%) wild-type littermates (P< 0.
View Article and Find Full Text PDFExcitatory and inhibitory synapses may control neuronal output through a push-pull mechanism--that is, increases in excitation are coupled to simultaneous decreases in inhibition or vice versa. This pattern of activity is characteristic of excitatory and inhibitory vestibulospinal axons that mediate vestibulocollic reflexes. Previously, we showed that medial vestibulospinal tract (MVST) neurons in the rostral descending vestibular nucleus (DVN), an excitatory pathway, primarily innervate the medial dendrites of contralateral splenius motoneurons.
View Article and Find Full Text PDFIt is well established that long, descending axons of the adult mammalian spinal cord do not regenerate after a spinal cord injury (SCI). These axons do not regenerate because they do not mount an adequate regenerative response and growth is inhibited at the injury site by growth cone collapsing molecules, such as chondroitin sulfate proteoglycans (CSPGs). However, whether axons of axotomized spinal interneurons regenerate through the inhibitory environment of an SCI site remains unknown.
View Article and Find Full Text PDFThe ability of inhibitory synaptic inputs to dampen the excitability of motoneurons is augmented when persistent inward currents (PICs) are activated. This amplification could be due to an increase in the driving potential of inhibitory synapses or the deactivation of the channels underlying PICs. Our goal was to determine which mechanism leads to the amplification of inhibitory inputs by PICs.
View Article and Find Full Text PDFIn some motoneurons, L-type Ca2+ channels that partly mediate persistent inward currents (PICs) have been estimated to be arranged in 50- to 200-microm-long discrete regions in the dendrites, centered 100 to 400 microm from the soma. As a consequence of this nonuniform distribution, the interaction between synaptic inputs to motoneurons and these channels may vary according to the distribution of the synapses. For instance, >93% of synapses from Renshaw cells have been observed to be located 65 to 470 microm away from the cell body of motoneurons.
View Article and Find Full Text PDFPrevious studies show that the activation of voltage-dependent channels is dependent on the local density of synapses in the dendritic region containing voltage-dependent channels. We hypothesized that the selective innervation of excitatory vestibulospinal (VST) neurons on the medial dendrites of contralateral splenius motoneurons is designed to enhance the activation of persistent inward currents (PICs) mediated by dendritic L-type Ca(2+) channels. Using compartmental models of splenius motoneurons we compared the synaptic current reaching the soma in response to excitatory input generated by synapses with two different distribution patterns.
View Article and Find Full Text PDFFollowing proximal axotomy, several types of neurons sprout de novo axons from distal dendrites. These processes may represent a means of forming new circuits following spinal cord injury. However, it is not know whether mammalian spinal interneurons, axotomized as a result of a spinal cord injury, develop de novo axons.
View Article and Find Full Text PDFIn the presence of monoamines, L-type Ca(2+) channels on the dendrites of motoneurons contribute to persistent inward currents (PICs) that can amplify synaptic inputs two- to sixfold. However, the exact location of the L-type Ca(2+) channels is controversial, and the importance of the location as a means of regulating the input-output properties of motoneurons is unknown. In this study, we used a computational strategy developed previously to estimate the dendritic location of the L-type Ca(2+) channels and test the hypothesis that the location of L-type Ca(2+) channels varies as a function of motoneuron size.
View Article and Find Full Text PDFIn the presence of neuromodulators such as serotonin and noradrenaline, motoneurons exhibit persistent inward currents (PICs) that serve to amplify synaptic inputs. A major component of these PICs is mediated by L-type Ca(2+) channels. Estimates based on electrophysiological studies indicate that these channels are located on the dendrites, but immunohistochemical studies of their precise distribution have yielded different results.
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