Simultaneous double gastrojejunostomy for afferent and efferent limb syndromes.
Ontology highlight
ABSTRACT:
SUBMITTER: Ichkhanian Y
PROVIDER: S-EPMC7332759 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description: Not available
| S-EPMC5989140 | biostudies-literature
Project description:IntroductionThe lateral habenula (LHb) is an epithalamic nucleus associated with negative valence and affective disorders. It receives input via the stria medullaris (SM) and sends output via the fasciculus retroflexus (FR). Here, we use tractography to reconstruct and characterize this pathway.MethodsMulti-shell human diffusion magnetic resonance imaging (dMRI) data was obtained from the human connectome project (HCP) (n = 20, 10 males) and from healthy controls (n = 10, 6 males) scanned at our institution. We generated LHb afferents and efferents using probabilistic tractography by selecting the pallidum as the seed region and the ventral tegmental area as the output target.ResultsWe were able to reconstruct the intended streamlines in all individuals from the HCP dataset and our dataset. Our technique also aided in identification of the LHb. In right-handed individuals, the streamlines were significantly more numerous in the left hemisphere (mean ratio 1.59 ± 0.09, p = 0.04). In left-handed individuals, there was no hemispheric asymmetry on average (mean ratio 1.00 ± 0.09, p = 1.0). Additionally, these streamlines were significantly more numerous in females than in males (619.9 ± 159.7 vs. 225.9 ± 66.03, p = 0.04).ConclusionWe developed a method to reconstruct the SM and FR without manual identification of the LHb. This technique enables targeting of these fiber tracts as well as the LHb. Furthermore, we have demonstrated that there are sex and hemispheric differences in streamline number. These findings may have therapeutic implications and warrant further investigation.
| S-EPMC9243380 | biostudies-literature
Project description:The claustrum (CLA) is a conspicuous subcortical structure interconnected with cortical and subcortical regions. Its regional anatomy and cell-type-specific connections in the mouse remain not fully determined. Using multimodal reference datasets, we confirmed the delineation of the mouse CLA as a single group of neurons embedded in the agranular insular cortex. We quantitatively investigated brain-wide inputs and outputs of CLA using bulk anterograde and retrograde viral tracing data and single neuron tracing data. We found that the prefrontal module has more cell types projecting to the CLA than other cortical modules, with layer 5 IT neurons predominating. We found nine morphological types of CLA principal neurons that topographically innervate functionally linked cortical targets, preferentially the midline cortical areas, secondary motor area, and entorhinal area. Together, this study provides a detailed wiring diagram of the cell-type-specific connections of the mouse CLA, laying a foundation for studying its functions at the cellular level.
| S-EPMC10415534 | biostudies-literature
Project description:In tactile sensing, decoding the journey from afferent tactile signals to efferent motor commands is a significant challenge primarily due to the difficulty in capturing population-level afferent nerve signals during active touch. This study integrates a finite element hand model with a neural dynamic model by using microneurography data to predict neural responses based on contact biomechanics and membrane transduction dynamics. This research focuses specifically on tactile sensation and its direct translation into motor actions. Evaluations of muscle synergy during in -vivo experiments revealed transduction functions linking tactile signals and muscle activation. These functions suggest similar sensorimotor strategies for grasping influenced by object size and weight. The decoded transduction mechanism was validated by restoring human-like sensorimotor performance on a tendon-driven biomimetic hand. This research advances our understanding of translating tactile sensation into motor actions, offering valuable insights into prosthetic design, robotics, and the development of next-generation prosthetics with neuromorphic tactile feedback.
| S-EPMC11316806 | biostudies-literature
Project description:Renal sympathetic denervation (RDNx) has emerged as a novel therapy for hypertension; however, the therapeutic mechanisms remain unclear. Efferent renal sympathetic nerve activity has recently been implicated in trafficking renal inflammatory immune cells and inflammatory chemokine and cytokine release. Several of these inflammatory mediators are known to activate or sensitize afferent nerves. This study aimed to elucidate the roles of efferent and afferent renal nerves in renal inflammation and hypertension in the deoxycorticosterone acetate (DOCA) salt rat model. Uninephrectomized male Sprague-Dawley rats (275-300 g) underwent afferent-selective RDNx (n=10), total RDNx (n=10), or Sham (n=10) and were instrumented for the measurement of mean arterial pressure and heart rate by radiotelemetry. Rats received 100-mg DOCA (SC) and 0.9% saline for 21 days. Resting afferent renal nerve activity in DOCA and vehicle animals was measured after the treatment protocol. Renal tissue inflammation was assessed by renal cytokine content and T-cell infiltration and activation. Resting afferent renal nerve activity, expressed as a percent of peak afferent nerve activity, was substantially increased in DOCA than in vehicle (35.8±4.4 versus 15.3±2.8 %Amax). The DOCA-Sham hypertension (132±12 mm Hg) was attenuated by ≈50% in both total RDNx (111±8 mm Hg) and afferent-selective RDNx (117±5 mm Hg) groups. Renal inflammation induced by DOCA salt was attenuated by total RDNx and unaffected by afferent-selective RDNx. These data suggest that afferent renal nerve activity may mediate the hypertensive response to DOCA salt, but inflammation may be mediated primarily by efferent renal sympathetic nerve activity. Also, resting afferent renal nerve activity is elevated in DOCA salt rats, which may highlight a crucial neural mechanism in the development and maintenance of hypertension.
| S-EPMC5159336 | biostudies-literature
Project description:Acetylcholine is the major neurotransmitter of the olivocochlear efferent system, which provides feedback to cochlear hair cells and sensory neurons. To study the role of cochlear muscarinic receptors, we studied receptor localization with immunohistochemistry and reverse transcription-PCR and measured olivocochlear function, cochlear responses, and histopathology in mice with targeted deletion of each of the five receptor subtypes. M2, M4, and M5 were detected in microdissected immature (postnatal days 10-13) inner hair cells and spiral ganglion cells but not outer hair cells. In the adult (6 weeks), the same transcripts were found in microdissected organ of Corti and spiral ganglion samples. M2 protein was found, by immunohistochemistry, in olivocochlear fibers in both outer and inner hair cell areas. M3 mRNA was amplified only from whole cochleas, and M1 message was never seen in wild-type ears. Auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) were unaffected by loss of Gq-coupled receptors (M1, M3, or M5), as were shock-evoked olivocochlear effects and vulnerability to acoustic injury. In contrast, loss of Gi-coupled receptors (M2 and/or M4) decreased neural responses without affecting DPOAEs (at low frequencies). This phenotype and the expression pattern are consistent with excitatory muscarinic signaling in cochlear sensory neurons. At high frequencies, both ABRs and DPOAEs were attenuated by loss of M2 and/or M4, and the vulnerability to acoustic injury was dramatically decreased. This aspect of the phenotype and the expression pattern are consistent with a presynaptic role for muscarinic autoreceptors in decreasing ACh release from olivocochlear terminals during high-level acoustic stimulation and suggest that muscarinic antagonists could enhance the resistance of the inner ear to noise-induced hearing loss.
| S-EPMC3332094 | biostudies-literature
Project description:The axonal projections and synaptic input of the C1 adrenergic neurons of the rostral ventrolateral medulla (VLM) were examined using transgenic dopamine-beta hydroxylase Cre mice and modified rabies virus. Cre-dependent viral vectors expressing TVA (receptor for envelopeA) and rabies glycoprotein were injected into the left VLM. EnvelopeA-pseudotyped rabies-EGFP glycoprotein-deficient virus (rabies-EGFP) was injected 4-6 weeks later in either thoracic spinal cord (SC) or hypothalamus. TVA immunoreactivity was detected almost exclusively (95 %) in VLM C1 neurons. In mice with SC injections of rabies-EGFP, starter cells (expressing TVA + EGFP) were found at the rostral end of the VLM; in mice with hypothalamic injections starter C1 cells were located more caudally. C1 neurons innervating SC or hypothalamus had other terminal fields in common (e.g., dorsal vagal complex, locus coeruleus, raphe pallidus and periaqueductal gray matter). Putative inputs to C1 cells with SC or hypothalamic projections originated from the same brain regions, especially the lower brainstem reticular core from spinomedullary border to rostral pons. Putative input neurons to C1 cells were also observed in the nucleus of the solitary tract, caudal VLM, caudal spinal trigeminal nucleus, cerebellum, periaqueductal gray matter and inferior and superior colliculi. In sum, regardless of whether they innervate SC or hypothalamus, VLM C1 neurons receive input from the same general brain regions. One interpretation is that many types of somatic or internal stimuli recruit these neurons en bloc to produce a stereotyped acute stress response with sympathetic, parasympathetic, vigilance and neuroendocrine components.
| S-EPMC4864159 | biostudies-literature
Project description:BackgroundDifferent classes of unmyelinated nerve fibers appear to exhibit distinct conductive properties. We sought a criterion based on conduction properties for distinguishing sympathetic efferents and unmyelinated, primary afferents in peripheral nerves.Methodology/principal findingsIn anesthetized monkey, centrifugal or centripetal recordings were made from single unmyelinated nerve fibers in the peroneal or sural nerve, and electrical stimuli were applied to either the sciatic nerve or the cutaneous nerve endings, respectively. In centrifugal recordings, electrical stimulation at the sympathetic chain and dorsal root was used to determine the fiber's origin. In centrifugal recordings, sympathetic fibers exhibited absolute speeding of conduction to a single pair of electrical stimuli separated by 50 ms; the second action potential was conducted faster (0.61 0.16%) than the first unconditioned action potential. This was never observed in primary afferents. Following 2 Hz stimulation (3 min), activity-dependent slowing of conduction in the sympathetics (8.6 0.5%) was greater than in one afferent group (6.7 0.5%) but substantially less than in a second afferent group (29.4 1.9%). In centripetal recordings, most mechanically-insensitive fibers also exhibited absolute speeding to twin pulse stimulation. The subset that did not show this absolute speeding was responsive to chemical stimuli (histamine, capsaicin) and likely consists of mechanically-insensitive afferents. During repetitive twin pulse stimulation, mechanosensitive afferents developed speeding, and speeding in sympathetic fibers increased.Conclusions/significanceThe presence of absolute speeding provides a criterion by which sympathetic efferents can be differentiated from primary afferents. The differences in conduction properties between sympathetics and afferents likely reflect differential expression of voltage-sensitive ion channels.
| S-EPMC2816714 | biostudies-literature
Project description:Vision, which requires extensive neural involvement, is often impaired in Alzheimer’s disease (AD). Over the last few decades, accumulating evidence has shown that various visual functions and structures are compromised in Alzheimer’s dementia and when measured can detect those with dementia from those with normal aging. These visual changes involve both the afferent and efferent parts of the visual system, which correspond to the sensory and eye movement aspects of vision, respectively. There are fewer, but a growing number of studies, that focus on the detection of predementia stages. Visual biomarkers that detect these stages are paramount in the development of successful disease-modifying therapies by identifying appropriate research participants and in identifying those who would receive future therapies. This review provides a summary and update on common afferent and efferent visual markers of AD with a focus on mild cognitive impairment (MCI) and preclinical disease detection. We further propose future directions in this area. Given the ease of performing visual tests, the accessibility of the eye, and advances in ocular technology, visual measures have the potential to be effective, practical, and non-invasive biomarkers of AD.
| S-EPMC7518395 | biostudies-literature
Project description:Peripheral nerve injury impairs motor and sensory function in humans, and its functional recovery largely depends on the axonal outgrowth required for the accurate reinnervation of appropriate targets. To better understand how motor and sensory nerve fibres select their terminal pathways, an unbiased cDNA microarray analysis was conducted to examine differential gene expression patterns in peripheral efferent and afferent fibres at different developmental stages in mice. Gene ontology (GO) and Kyoto Enrichment of Genes and Genomes (KEGG) analyses revealed common and distinct features of enrichment for differentially expressed genes during motor and sensory nerve fibre development. Ingenuity Pathway Analysis (IPA) further indicated that the key differentially expressed genes were associated with trans-synaptic neurexin-neuroligin signalling components and a variety of gamma-aminobutyric acid (GABA) receptors. The aim of this study was to generate a framework of gene networks regulated during motor and sensory neuron differentiation/maturation. These data may provide new clues regarding the underlying cellular and molecular mechanisms that determine the intrinsic capacity of neurons to regenerate after peripheral nerve injury. Our findings may thus facilitate further development of a potential intervention to manipulate the therapeutic efficiency of peripheral nerve repair in the clinic.
| S-EPMC6086926 | biostudies-literature