RESUMO
In the spinal cord, sensory-motor circuits controlling motor activity are situated in the dorso-ventral interface. The neurons identified by the expression of the transcription factor Doublesex and mab-3 related transcription factor 3 (Dmrt3) have previously been associated with the coordination of locomotion in horses (Equus caballus, Linnaeus, 1758), mice (Mus musculus, Linnaeus, 1758), and zebrafish (Danio rerio, F. Hamilton, 1822). Based on earlier studies, we hypothesized that, in mice, these neurons may be positioned to receive sensory and central inputs to relay processed commands to motor neurons. Thus, we investigated the presynaptic inputs to spinal Dmrt3 neurons using monosynaptic retrograde replication-deficient rabies tracing. The analysis showed that lumbar Dmrt3 neurons receive inputs from intrasegmental neurons, and intersegmental neurons from the cervical, thoracic, and sacral segments. Some of these neurons belong to the excitatory V2a interneurons and to plausible Renshaw cells, defined by the expression of Chx10 and calbindin, respectively. We also found that proprioceptive primary sensory neurons of type Ia2, Ia3, and Ib, defined by the expression of calbindin, calretinin, and Brn3c, respectively, provide presynaptic inputs to spinal Dmrt3 neurons. In addition, we demonstrated that Dmrt3 neurons receive inputs from brain areas involved in motor regulation, including the red nucleus, primary sensory-motor cortex, and pontine nuclei. In conclusion, adult spinal Dmrt3 neurons receive inputs from motor-related brain areas as well as proprioceptive primary sensory neurons and have been shown to connect directly to motor neurons. Dmrt3 neurons are thus positioned to provide sensory-motor control and their connectivity is suggestive of the classical reflex pathways present in the spinal cord.
Assuntos
Fatores de Transcrição , Peixe-Zebra , Camundongos , Animais , Cavalos , Fatores de Transcrição/metabolismo , Peixe-Zebra/metabolismo , Neurônios Motores/fisiologia , Medula Espinal/metabolismo , Interneurônios/metabolismo , Calbindinas/metabolismo , Tronco Encefálico/metabolismoRESUMO
BACKGROUND: Doppler ultrasound can diagnose testicular torsion with high sensitivity and specificity but may delay surgical treatment. This study aims to assess whether the use of doppler ultrasound, in cases with intermediate clinical suspicion of testicular torsion, can improve diagnostic accuracy compared to clinical assessment alone. METHODS: We implemented a new clinical algorithm where patients with intermediate suspicion of testicular torsion undergo doppler ultrasound within 60 min. This study compared the patients that presented within one year prior to the implementation (group 1) to the patients who presented within one year after the implementation (group 2). The primary outcome measure was failure to confirm testicular torsion upon surgical exploration (negative surgical exploration). Missed testicular torsion was one of the secondary endpoints. RESULTS: 590 consecutive patients were included. 322 (55%) in group 1 and 268 (45%) in group 2. There were 9 (2.8%) testicular torsions in group 1 vs 9 (3.4%) in group 2 (p = 0.69) and 2 (0.6%) missed testicular torsions in group 1 vs 0 in group 2 (p = 0.50). Doppler ultrasound was performed in 65 patients (24.2%) in group 2 vs 0 in group 1 (p < 0.01). Negative surgical exploration was performed in 27 (8.4%) patients in group 1 vs 8 (3.0%) in group 2 (p < 0.01). CONCLUSION: Doppler ultrasound assessment of patients at intermediate clinical risk of testicular torsion significantly reduced the frequency of negative surgical explorations without increased rate of missed testicular torsions.
Assuntos
Torção do Cordão Espermático , Humanos , Masculino , Estudos Retrospectivos , Escroto , Torção do Cordão Espermático/diagnóstico por imagem , Ultrassonografia , Ultrassonografia Doppler em CoresRESUMO
MOTIVATION: Cell to cell communication is critical for all multicellular organisms, and single-cell sequencing facilitates the construction of full connectivity graphs between cell types in tissues. Such complex data structures demand novel analysis methods and tools for exploratory analysis. RESULTS: We propose a method to predict the putative ligand-receptor interactions between cell types from single-cell RNA-sequencing data. This is achieved by inferring and incorporating interactions in a multi-directional graph, thereby enabling contextual exploratory analysis. We demonstrate that our approach can detect common and specific interactions between cell types in mouse brain and human tumors, and that these interactions fit with expected outcomes. These interactions also include predictions made with molecular ligands integrating information from several types of genes necessary for ligand production and transport. Our implementation is general and can be appended to any transcriptome analysis pipeline to provide unbiased hypothesis generation regarding ligand to receptor interactions between cell populations or for network analysis in silico. AVAILABILITY AND IMPLEMENTATION: scConnect is open source and available as a Python package at https://github.com/JonETJakobsson/scConnect. scConnect is directly compatible with Scanpy scRNA-sequencing pipelines. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
RESUMO
The spinal locomotor network is frequently used for studies into how neuronal circuits are formed and how cellular activity shape behavioral patterns. A population of dI6 interneurons, marked by the Doublesex and mab-3 related transcription factor 3 (Dmrt3), has been shown to participate in the coordination of locomotion and gaits in horses, mice and zebrafish. Analyses of Dmrt3 neurons based on morphology, functionality and the expression of transcription factors have identified different subtypes. Here we analyzed the transcriptomes of individual cells belonging to the Dmrt3 lineage from zebrafish and mice to unravel the molecular code that underlies their subfunctionalization. Indeed, clustering of Dmrt3 neurons based on their gene expression verified known subtypes and revealed novel populations expressing unique markers. Differences in birth order, differential expression of axon guidance genes, neurotransmitters, and their receptors, as well as genes affecting electrophysiological properties, were identified as factors likely underlying diversity. In addition, the comparison between fish and mice populations offers insights into the evolutionary driven subspecialization concomitant with the emergence of limbed locomotion.
RESUMO
Itch stimuli are detected by specialized primary afferents that convey the signal to the spinal cord, but how itch transmission is regulated is still not completely known. Here, we investigated the roles of the neuropeptide Y (NPY)/Y2 receptor system on scratch behavior. The inhibitory Y2 receptor is expressed on mouse primary afferents, and intrathecal administration of the Y2 agonist peptide YY (PYY)3-36 reduced scratch episode frequency and duration induced by compound 48/80, an effect that could be reversed by intrathecal preadministration of the Y2 antagonist BIIE0246. Also, scratch episode duration induced by histamine could be reduced by PYY3-36 In contrast, scratch behavior induced by α-methyl-5HT, protease-activated receptor-2-activating peptide SLIGRL, chloroquine, topical dust mite extract, or mechanical itch induced by von Frey filaments was unaffected by stimulation of Y2 Primary afferent neurons expressing the Npy2r gene were found to coexpress itch-associated markers such as natriuretic peptide precursor b, oncostatin M receptor, and interleukin (IL) 31 receptor A. Accordingly, intrathecal PYY3-36 reduced the scratch behavior induced by IL-31. Our findings imply that the NPY/Y2 system reduces histaminergic and IL-31-associated itch through presynaptic inhibition of a subpopulation of itch-associated primary afferents. SIGNIFICANCE STATEMENT: The spinal neuropeptide Y system dampens scratching behavior induced by histaminergic compounds and interleukin 31, a cytokine involved in atopic dermatitis, through interactions with the Y2 receptor. The Y2 receptor is expressed by primary afferent neurons that are rich in itch-associated neurotransmitters and receptors such as somatostatin, natriuretic peptide precursor b, and interleukin 31 receptors.
Assuntos
Antipruriginosos/farmacologia , Dermatite Atópica/metabolismo , Neurônios Aferentes/metabolismo , Fragmentos de Peptídeos/farmacologia , Peptídeo YY/farmacologia , Prurido/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Animais , Antipruriginosos/administração & dosagem , Antipruriginosos/uso terapêutico , Arginina/análogos & derivados , Arginina/toxicidade , Benzazepinas/toxicidade , Células Cultivadas , Cloroquina/farmacologia , Dermatite Atópica/tratamento farmacológico , Gânglios Espinais/citologia , Histamina/farmacologia , Histamina/toxicidade , Interleucinas/farmacologia , Interleucinas/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Peptídeo Natriurético Encefálico/genética , Peptídeo Natriurético Encefálico/metabolismo , Neurônios Aferentes/efeitos dos fármacos , Neurônios Aferentes/fisiologia , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/uso terapêutico , Peptídeo YY/administração & dosagem , Peptídeo YY/uso terapêutico , Prurido/tratamento farmacológico , Prurido/etiologia , Receptores de Neuropeptídeo Y/genética , Receptores de Oncostatina M/genética , Receptores de Oncostatina M/metabolismo , Serotonina/farmacologiaRESUMO
Itch is a somatosensory sensation that informs the organism about the presence of potentially harmful substances or parasites, and initiates scratching to remove the threat. Itch-inducing (pruritogenic) substances activate primary afferent neurons in the skin through interactions with specific receptors that converts the stimulus into an electrical signal. These signals are conveyed to the dorsal horn of the spinal cord through the release of neurotransmitters such as natriuretic polypeptide b and somatostatin, leading to an integrated response within a complex spinal interneuronal network. A large sub-population of somatostatin-expressing spinal interneurons also carry the Neuropeptide Y (NPY) Y1 receptor, indicating that NPY and somatostatin partly regulate the same neuronal pathway. This review focuses on recent findings regarding the role of the NPY/Y1 and somatostatin/SST2A receptor in itch, and also presents data integrating the two neurotransmitter systems.
Assuntos
Neurônios/metabolismo , Neuropeptídeo Y/metabolismo , Prurido/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Medula Espinal/metabolismo , Animais , Humanos , Vias Neurais/metabolismo , Receptores de Somatostatina/metabolismo , Somatostatina/metabolismoRESUMO
Dorsal horn gastrin-releasing peptide receptor (GRPR) neurons have a central role in itch transmission. Itch signaling has been suggested to be controlled by an inhibitory network in the spinal dorsal horn, as increased scratching behavior can be induced by pharmacological disinhibition or ablation of inhibitory interneurons, but the direct influence of the inhibitory tone on the GRPR neurons in the itch pathway have not been explored. Here we have investigated spinal GRPR neurons through in vitro and bioinformatical analysis. Electrophysiological recordings revealed that GRPR neurons receive local spontaneous excitatory inputs transmitted by glutamate and inhibitory inputs by glycine and GABA, which were transmitted either by separate glycinergic and GABAergic synapses or by glycine and GABA co-releasing synapses. Additionally, all GRPR neurons received both glycine- and GABA-induced tonic currents. The findings show a complex inhibitory network, composed of synaptic and tonic currents that gates the excitability of GRPR neurons, which provides direct evidence for the existence of an inhibitory tone controlling spontaneous discharge in an itch-related neuronal network in the spinal cord. Finally, calcium imaging revealed increased levels of neuronal activity in Grpr-Cre neurons upon application of somatostatin, which provides direct in vitro evidence for disinhibition of these dorsal horn interneurons.
Assuntos
Interneurônios/metabolismo , Inibição Neural/fisiologia , Receptores da Bombesina/metabolismo , Medula Espinal/metabolismo , Potenciais de Ação/efeitos dos fármacos , Animais , Feminino , Glicina/metabolismo , Integrases/metabolismo , Interneurônios/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Células do Corno Posterior/efeitos dos fármacos , Células do Corno Posterior/metabolismo , Subunidades Proteicas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Somatostatina/farmacologia , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
The dorsal horn of the spinal cord is critical to processing distinct modalities of noxious and innocuous sensation, but little is known of the neuronal subtypes involved, hampering efforts to deduce principles governing somatic sensation. Here we used single-cell RNA sequencing to classify sensory neurons in the mouse dorsal horn. We identified 15 inhibitory and 15 excitatory molecular subtypes of neurons, equaling the complexity in cerebral cortex. Validating our classification scheme in vivo and matching cell types to anatomy of the dorsal horn by spatial transcriptomics reveals laminar enrichment for each of the cell types. Neuron types, when combined, define a multilayered organization with like neurons layered together. Employing our scheme, we find that heat and cold stimuli activate discrete sets of both excitatory and inhibitory neuron types. This work provides a systematic and comprehensive molecular classification of spinal cord sensory neurons, enabling functional interrogation of sensory processing.
Assuntos
Atlas como Assunto , Neurônios/fisiologia , Sensação/fisiologia , Corno Dorsal da Medula Espinal/fisiologia , Transcriptoma/genética , Animais , Temperatura Baixa , Feminino , Glutamatos/fisiologia , Temperatura Alta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Neurônios/classificação , Células do Corno Posterior/fisiologia , RNA/genética , Células Receptoras Sensoriais/classificação , Células Receptoras Sensoriais/fisiologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Corno Dorsal da Medula Espinal/anatomia & histologiaRESUMO
The role of calcitonin gene-related peptide (CGRP) in visceral and somatic nociception is incompletely understood. CGRPα is highly expressed in sensory neurons of dorsal root ganglia and particularly in neurons that also express the transient receptor potential cation channel subfamily V member 1 (Trpv1). Therefore, we investigated changes in visceral and somatic nociception following deletion of CGRPα from the Trpv1-Cre population using the Cre/lox system. In control mice, acetic acid injection (0.6%, ip) caused significant immobility (time stationary), an established indicator of visceral pain. In CGRPα-mCherrylx/lx;Trpv1-Cre mice, the duration of immobility was significantly less than controls, and the distance CGRPα-mCherrylx/lx;Trpv1-Cre mice traveled over 20 min following acetic acid was significantly greater than controls. However, following acetic acid injection, there was no difference between genotypes in the writhing reflex, number of abdominal licks, or forepaw wipes of the cheek. CGRPα-mCherrylx/lx;Trpv1-Cre mice developed more pronounced inflammation-induced heat hypersensitivity above baseline values compared with controls. However, analyses of noxious acute heat or cold transmission revealed no difference between genotypes. Also, odor avoidance test, odor preference test, and buried food test for olfaction revealed no differences between genotypes. Our findings suggest that CGRPα-mediated transmission within the Trpv1-Cre population plays a significant role in visceral nociceptive pathways underlying voluntary movement. Monitoring changes in movement over time is a sensitive parameter to identify differences in visceral nociception, compared with writhing reflexes, abdominal licks, or forepaw wipes of the cheek that were unaffected by deletion of CGRPα- from Trpv1-Cre population and likely utilize different mechanisms. NEW & NOTEWORTHY The neuropeptide calcitonin gene-related peptide (CGRP) is highly colocalized with transient receptor potential cation channel subfamily V member 1 (TRPV1)-expressing primary afferent neurons, but the functional role of CGRPα specifically in these neurons is unknown in pain processing from visceral and somatic afferents. We used cre-lox recombination to conditionally delete CGRPα from TRPV1-expressing neurons in mice. We show that CGRPα from within TRPV1-cre population plays an important role in visceral nociception but less so in somatic nociception.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Gânglios Espinais/metabolismo , Integrases/metabolismo , Nociceptividade , Dor Nociceptiva/metabolismo , Canais de Cátion TRPV/metabolismo , Dor Visceral/metabolismo , Ácido Acético , Animais , Comportamento Animal , Peptídeo Relacionado com Gene de Calcitonina/deficiência , Peptídeo Relacionado com Gene de Calcitonina/genética , Modelos Animais de Doenças , Gânglios Espinais/fisiopatologia , Temperatura Alta , Integrases/genética , Masculino , Camundongos Knockout , Atividade Motora , Dor Nociceptiva/etiologia , Dor Nociceptiva/genética , Dor Nociceptiva/fisiopatologia , Tempo de Reação , Células Receptoras Sensoriais/metabolismo , Canais de Cátion TRPV/genética , Dor Visceral/induzido quimicamente , Dor Visceral/genética , Dor Visceral/fisiopatologiaRESUMO
OBJECTIVE: The aim of this study was to evaluate clinically relevant complications within 14 days after extracorporeal shockwave lithotripsy (ESWL) in a modern setting. MATERIALS AND METHODS: Consecutive ESWL treatments between 2009 and 2015 in Ängelholm Hospital, Sweden, were analyzed retrospectively. The primary outcome was complications in patients seeking medical attention within 14 days after ESWL. Multivariable analysis was used to adjust for confounders such as diabetes, stone size and location, and presence of a urinary stent. RESULTS: In total, 1838 stones were treated: 1185 (64.4%) localized in the renal pelvis, and 415 (22.5%) in the upper two-thirds and 205 (11.1%) in the lower third of the ureter. Overall, 116 out of 1838 cases (6.4%) needed medical attention within 14 days after ESWL and 75 (4%) crequired hospital care. Infection was found in 44 cases (2.4%), with a positive urine culture in 33 cases. Invasive/operative interventions were performed in 41 cases (2.2%). Distal stones had a lower risk of complications (p = 0.02) with ESWL. Diabetes (p = 0.02), larger stones (11-20 mm, p = 0.03; 21-30 mm, p = 0.009) and a need for antiemetics during treatment (p = 0.02) were significantly associated with an increased risk of complications. CONCLUSIONS: Few complications are associated with modern ESWL treatment. A frequency of 1 Hz should be used to reduce complications (p = 0.025). Diabetes and larger stone size increase the risk of complications. The need for antiemetics during ESWL requires special consideration and further study. Distal stones seem to carry a lower risk of complications (p = 0.017).