Mechanisms underlying the recruitment of inhibitory interneurons in fictive swimming in developing Xenopus laevis tadpoles

Funding: Authors thank BBSRC for funding this research (BB/L000814/1 to R.B.; BB/T003146 to W.L.).Developing spinal circuits generate patterned motor outputs while many neurons with high membrane resistances are still maturing. In the spinal cord of hatchling frog tadpoles of unknown sex, we found that the firing reliability in swimming of inhibitory interneurons with commissural and ipsilateral ascending axons was negatively correlated with their cellular membrane resistance. Further analyses showed that neurons with higher resistances had outward rectifying properties, low firing thresholds and little delay in firing evoked by current injections. Input synaptic currents these neurons received during swimming, either compoundˎ unitary current amplitudes or unitary synaptic current numbers, were scaled with their membrane resistances, but their own synaptic outputs were correlated with membrane resistances of their postsynaptic partners. Analyses of neuronal dendritic and axonal lengths and their activities in swimming and cellular input resistances did not reveal a clear correlation pattern. Incorporating these electrical and synaptic properties in a computer swimming model produced robust swimming rhythms whereas randomising input synaptic strengths led to the breakdown of swimming rhythms, coupled with less synchronised spiking in the inhibitory interneurons. We conclude that the recruitment of these developing interneurons in swimming can be predicted by cellular input resistances, but the order is opposite to the motor-strength based recruitment scheme depicted by Henneman’s size principle. This form of recruitment/integration order in development before the emergence of refined motor control is progressive potentially with neuronal acquisition of mature electrical and synaptic properties, among which the scaling of input synaptic strengths with cellular input resistance plays a critical role.PostprintPeer reviewe

TikTok content as a source of health education regarding epicondylitis: a content analysis

Purpose This study aimed to assess the validity and informational value of TikTok content about epicondylitis. The hypothesis tested herein was that TikTok video content would not provide adequate and valid information. Methods The term "epicondylitis" was used as a keyword to comprehensively search for TikTok videos, and the first 100 videos that were retrieved were subsequently included for analysis. The duration, number of likes, number of shares and number of views were recorded for each video. Furthermore, the videos were categorized on the basis of their source (medical doctor, physiotherapist, or private user), type of information (physical therapy, anatomy, clinical examination, etiopathogenesis, patient experience, treatment, or other), video content (rehabilitation, education, or patient experience/testimony), and the presence of music or voice. Assessments of video content quality and reliability were conducted using the DISCERN tool, the Journal of the American Medical Association (JAMA) benchmark criteria, and the Global Quality Score (GQS). Results A total of 100 videos were included in the analysis: 78 (78.0%) were published by physiotherapists, 18 were published by medical doctors (18.0%), and 4 were published by private users (4.0%). Most of the information pertained to physical therapy (75; 75.0%) and most of the content was about rehabilitation (75; 75.0%). The mean length of the videos was 42.51 +/- 24.75 seconds; the mean number of views was 193,207.78 +/- 1,300,853.86; and the mean number of comments, likes, and shares were 22.43 +/- 62.54, 1578.52 +/- 8333.11, and 149.87 +/- 577.73, respectively. The mean DISCERN score, JAMA score, and GQS were 18.12 +/- 5.73, 0.80 +/- 0.53, and 1.30 +/- 0.52, respectively. Videos posted by medical doctors/private users had higher scores (p < 0.05) than videos posted by physiotherapists. Videos that focused on education or patient experience had higher scores (p < 0.05) than videos based on rehabilitation. Conclusions TikTok can be an unreliable source of information regarding epicondylitis treatment. It is common to find nonphysicians who share medical advice on the platform, with medical treatments demonstrating the weakest level of supporting evidence. Elbow surgeons should advise their patients that treatment recommendations from TikTok may not align with established guidelines.Level of Evidence: Level IV-Cross-sectional study

The early development and physiology of Xenopus laevis tadpole lateral line system

Valentina Saccomanno was an exchange MSc student in the University of St Andrews with a scholarship by the Erasmus+ Programme for Traineeship and the University of Trieste. This project was partly supported by a BBSRC grant (BB/T003146).Xenopus laevis has a lateral line mechanosensory system throughout its full life cycle, and a previous study on prefeeding stage tadpoles revealed that it may play a role in motor responses to both water suction and water jets. Here, we investigated the physiology of the anterior lateral line system in newly hatched tadpoles and the motor outputs induced by its activation in response to brief suction stimuli. High-speed videoing showed tadpoles tended to turn and swim away when strong suction was applied close to the head. The lateral line neuromasts were revealed by using DASPEI staining, and their inactivation with neomycin eliminated tadpole motor responses to suction. In immobilized preparations, suction or electrically stimulating the anterior lateral line nerve reliably initiated swimming but the motor nerve discharges implicating turning was observed only occasionally. The same stimulation applied during ongoing fictive swimming produced a halting response. The anterior lateral line nerve showed spontaneous afferent discharges at rest and increased activity during stimulation. Efferent activities were only recorded during tadpole fictive swimming and were largely synchronous with the ipsilateral motor nerve discharges. Finally, calcium imaging identified neurons with fluorescence increase time-locked with suction stimulation in the hindbrain and midbrain. A cluster of neurons at the entry point of the anterior lateral line nerve in the dorsolateral hindbrain had the shortest latency in their responses, supporting their potential sensory interneuron identity. Future studies need to reveal how the lateral line sensory information is processed by the central circuit to determine tadpole motor behavior.Publisher PDFPeer reviewe

Undiagnosed cognitive impairment in older adults hospitalized in internal medicine wards: Data from the REPOSI registry

No abstract availabl

Statins, ACE/ARBs drug use, and risk of pneumonia in hospitalized older patients: a retrospective cohort study

The aims of this study is to evaluate the association between angiotensin-converting enzyme inhibitor (ACE-I), angiotensin II receptor blocker (ARBs) and/or statin use with the risk of pneumonia, as well as and with in-hospital and short-term outpatient mortality in hospitalized older patients with pneumonia. Patients aged 65 years or older hospitalized in internal medicine and/or geriatric wards throughout Italy and enrolled in the REPOSI (REgistro Politerapuie SIMI-Societa Italiana di Medicina Interna) register from 2010 to 2019 were screened to assess the diagnosis of pneumonia and classified on whether or not they were prescribed with at least one drug among ACE-I, ARBs, and/or statins. Further study outcomes were mortality during hospital stay and at 3 months after hospital discharge. Among 5717 cases included (of whom 18.0% with pneumonia), 2915 (51.0%) were prescribed at least one drug among ACE-I, ARBs, and statins. An inverse association was found between treatment with ACE-I or ARBs and pneumonia (OR = 0.79, 95% CI 0.65-0.95). A higher effect was found among patients treated with ACE-I or ARBs in combination with statins (OR = 0.67, 95% CI 0.52-0.85). This study confirmed in the real-world setting that these largely used medications may reduce the risk of pneumonia in older people, who chronically take them for cardiovascular conditions

Statins, ACE/ARBs drug use, and risk of pneumonia in hospitalized older patients: a retrospective cohort study

: The aims of this study is to evaluate the association between angiotensin-converting enzyme inhibitor (ACE-I), angiotensin II receptor blocker (ARBs) and/or statin use with the risk of pneumonia, as well as and with in-hospital and short-term outpatient mortality in hospitalized older patients with pneumonia. Patients aged 65 years or older hospitalized in internal medicine and/or geriatric wards throughout Italy and enrolled in the REPOSI (REgistro Politerapuie SIMI-Società Italiana di Medicina Interna) register from 2010 to 2019 were screened to assess the diagnosis of pneumonia and classified on whether or not they were prescribed with at least one drug among ACE-I, ARBs, and/or statins. Further study outcomes were mortality during hospital stay and at 3 months after hospital discharge. Among 5717 cases included (of whom 18.0% with pneumonia), 2915 (51.0%) were prescribed at least one drug among ACE-I, ARBs, and statins. An inverse association was found between treatment with ACE-I or ARBs and pneumonia (OR = 0.79, 95% CI 0.65-0.95). A higher effect was found among patients treated with ACE-I or ARBs in combination with statins (OR = 0.67, 95% CI 0.52-0.85). This study confirmed in the real-world setting that these largely used medications may reduce the risk of pneumonia in older people, who chronically take them for cardiovascular conditions