Contamination of equipment and surfaces in the operating room anesthesia workspace: a cross-sectional study

ABSTRACT BACKGROUND: Contamination of the breathing circuit and medication preparation surface of an anesthesia machine can increase the risk of cross-infection. OBJECTIVE: To evaluate the contamination of the anesthetic medication preparation surface, respiratory circuits, and devices used in general anesthesia with assisted mechanical ventilation. DESIGN AND SETTING: Cross-sectional, quantitative study conducted at the surgical center of a philanthropic hospital, of medium complexity located in the municipality of Três Lagoas, in the eastern region of the State of Mato Grosso do Sul. METHODS: Eighty-two microbiological samples were collected from the breathing circuits. After repeating the samples in different culture media, 328 analyses were performed. RESULTS: A higher occurrence of E. coli, Enterobacter spp., Pseudomonas spp., Staphylococcus aureus, and Streptococcus pneumoniae (P < 0.001) were observed. Variations were observed depending on the culture medium and sample collection site. CONCLUSION: The study findings underscore the inadequate disinfection of the inspiratory and expiratory branches, highlighting the importance of stringent cleaning and disinfection of high-touch surfaces.

Christofredo Jakob, los cimientos de la neurociencia argentina / Christofredo Jakob, the foundations of argentine neuroscience

El presente artículo es una reseña biográfica de la vida del Dr. Christofredo Jakob, desde su formación en Alemania, las personalidades que acompañaron su desarrollo y las publicaciones científicas en suelo germano. Luego llegarían los inicios de su trabajo en la Argentina y los principales alcances de sus investigaciones. A través de esta reseña recorremos los comienzos del estudio sistemático del sistema nervioso en el país y recordamos el Día del Neurocientífico argentino. (AU)

This article is a biographical review of the life of Dr. Christofredo Jakob, from his training in Germany, the personalities who accompanied his development and the scientific publications on German soil. Then came the beginnings of his work in Argentina and the main achievements of his research. Through this review, we retrace the beginnings of the systematic study of the nervous system in the country and we remember the Day of the Argentine Neuroscientist. (AU)

Neural Mechanisms Underlying the Coughing Reflex / 神经科学通报·英文版

Breathing is an intrinsic natural behavior and physiological process that maintains life. The rhythmic exchange of gases regulates the delicate balance of chemical constituents within an organism throughout its lifespan. However, chronic airway diseases, including asthma and chronic obstructive pulmonary disease, affect millions of people worldwide. Pathological airway conditions can disrupt respiration, causing asphyxia, cardiac arrest, and potential death. The innervation of the respiratory tract and the action of the immune system confer robust airway surveillance and protection against environmental irritants and pathogens. However, aberrant activation of the immune system or sensitization of the nervous system can contribute to the development of autoimmune airway disorders. Transient receptor potential ion channels and voltage-gated Na+ channels play critical roles in sensing noxious stimuli within the respiratory tract and interacting with the immune system to generate neurogenic inflammation and airway hypersensitivity. Although recent studies have revealed the involvement of nociceptor neurons in airway diseases, the further neural circuitry underlying airway protection remains elusive. Unraveling the mechanism underpinning neural circuit regulation in the airway may provide precise therapeutic strategies and valuable insights into the management of airway diseases.

Genetic Approaches for Neural Circuits Dissection in Non-human Primates / 神经科学通报·英文版

Genetic tools, which can be used for the morphology study of specific neurons, pathway-selective connectome mapping, neuronal activity monitoring, and manipulation with a spatiotemporal resolution, have been widely applied to the understanding of complex neural circuit formation, interactions, and functions in rodents. Recently, similar genetic approaches have been tried in non-human primates (NHPs) in neuroscience studies for dissecting the neural circuits involved in sophisticated behaviors and clinical brain disorders, although they are still very preliminary. In this review, we introduce the progress made in the development and application of genetic tools for brain studies on NHPs. We also discuss the advantages and limitations of each approach and provide a perspective for using genetic tools to study the neural circuits of NHPs.

A Neural Circuit Controlling Virgin Female Aggression Induced by Mating-related Cues in Drosophila / 神经科学通报·英文版

Females increase aggression for mating opportunities and for acquiring reproductive resources. Although the close relationship between female aggression and mating status is widely appreciated, whether and how female aggression is regulated by mating-related cues remains poorly understood. Here we report an interesting observation that Drosophila virgin females initiate high-frequency attacks toward mated females. We identify 11-cis-vaccenyl acetate (cVA), a male-derived pheromone transferred to females during mating, which promotes virgin female aggression. We subsequently reveal a cVA-responsive neural circuit consisting of four orders of neurons, including Or67d, DA1, aSP-g, and pC1 neurons, that mediate cVA-induced virgin female aggression. We also determine that aSP-g neurons release acetylcholine (ACh) to excite pC1 neurons via the nicotinic ACh receptor nAChRα7. Together, beyond revealing cVA as a mating-related inducer of virgin female aggression, our results identify a neural circuit linking the chemosensory perception of mating-related cues to aggressive behavior in Drosophila females.

Circuit-Specific Control of Blood Pressure by PNMT-Expressing Nucleus Tractus Solitarii Neurons / 神经科学通报·英文版

The nucleus tractus solitarii (NTS) is one of the morphologically and functionally defined centers that engage in the autonomic regulation of cardiovascular activity. Phenotypically-characterized NTS neurons have been implicated in the differential regulation of blood pressure (BP). Here, we investigated whether phenylethanolamine N-methyltransferase (PNMT)-expressing NTS (NTSPNMT) neurons contribute to the control of BP. We demonstrate that photostimulation of NTSPNMT neurons has variable effects on BP. A depressor response was produced during optogenetic stimulation of NTSPNMT neurons projecting to the paraventricular nucleus of the hypothalamus, lateral parabrachial nucleus, and caudal ventrolateral medulla. Conversely, photostimulation of NTSPNMT neurons projecting to the rostral ventrolateral medulla produced a robust pressor response and bradycardia. In addition, genetic ablation of both NTSPNMT neurons and those projecting to the rostral ventrolateral medulla impaired the arterial baroreflex. Overall, we revealed the neuronal phenotype- and circuit-specific mechanisms underlying the contribution of NTSPNMT neurons to the regulation of BP.

Neurophilic herpesvirus: a powerful tool for neuroscience research / 生物工程学报

Viruses are powerful tools for the study of modern neurosciences. Most of the research on the connection and function of neurons were done by using recombinant viruses, among which neurotropic herpesvirus is one of the most important tools. With the continuous development of genetic engineering and molecular biology techniques, several recombinant neurophilic herpesviruses have been engineered into different viral tools for neuroscience research. This review describes and discusses several common and widely used neurophilic herpesviruses as nerve conduction tracers, viral vectors for neurological diseases, and lytic viruses for neuro-oncology applications, which provides a reference for further exploring the function of neurophilic herpesviruses.

Effects of 6-week Circuit Training on Anaerobic Performance and Simple Reaction Time in Individuals with Intellectual Disability (ID) in Kelantan State (Kesan Latihan Litar Selama 6 Minggu Terhadap Prestasi Anaerobik dan Tindak Balas Masa Ringkas dalam Individu Kurang Daya Intektual (ID) di Negeri Kelantan) / Jurnal Sains Kesihatan Malaysia

@#Participation in exercise benefits health and fitness among Intellectual Disability (ID) individuals. Circuit training is one of the exercise programme that can be tailored by manipulating the intensity, time and types of exercise. The purpose of the present study is to examine the effects of six weeks of circuit training on anaerobic fitness and simple reaction time in ID individuals. Thirty participants with mild to moderate ID were selected from individuals who are registered with the Pusat Pemulihan dalam Komuniti (PDK) and Yayasan Orang Kurang Upaya (YOKUK) in the Kelantan state. Participants were randomly divided into Circuit Training and Control groups. Participants in Circuit Training group followed a circuit training exercise programme, two times per week for six weeks, whereas participants in Control group were not involved in circuit training and carried out their regular activities. The anaerobic peak power was significantly decreased (ƿ < 0.001) in Control group after six weeks. The anaerobic power of post-test was significantly improved (ƿ = 0.042) from the pre-test in Circuit Training group and it was also significantly higher (ƿ = 0.001) than Control group. There were no significant differences for the anaerobic capacity and simple reaction time between and within groups. Circuit training can be conducted to enhance anaerobic power in ID individuals, however longer participation may be needed to improve anaerobic capacity and simple reaction time.

Development of a flexible embedded neurostimulator for animal robots / 生物医学工程学杂志

The neural stimulator is a core component of animal robots. While the control effect of animal robots is influenced by various factors, the performance of the neural stimulator plays a decisive role in regulating animal robots. In order to optimize animal robots, embedded neural stimulators had been developed using flexible printed circuit board technology. This innovation not only enabled the stimulator to generate parameter-adjustable biphasic current pulses through control signals, but also optimized its carrying mode, material, and size, overcoming the disadvantages of traditional backpack or head-inserted stimulators, which have poor concealment and are prone to infection. Static, in vitro, and in vivo performance tests of the stimulator demonstrated that it not only had precise pulse waveform output capability, but also was lightweight and small in size. It had excellent in vivo performance in both laboratory and outdoor environments. Our study has high practical significance for the application of animal robots.

Working memory deficits in Parkinson's disease mouse model / 中国药理学与毒理学杂志

OBJECTIVE Parkinson's disease(PD)is a progressive neurodegenerative disease clinically char-acterized by dyskinesia,tremor,rigidity,abnormal gait,whereas 90%of patients with PD suffer from defects of the sense of smell before the appearance of the motor dysfunctions.However,the mechanism of olfactory disor-der is still not clear.METHODS We utilized olfaction based delayed paired association task in head-fixed mice.We focused on functional role of neural circuit using opto-genetic techniques.In addition,we viewed the synaptic transmission by slice physiological recording and count-ed the cell number of targeted circuits.RESULTS AND CONCLUSION In our experiments,olfactory working memory impairments were found in the PD mice,and the working memory impairment appeared before motor dys-functions.Furthermore,we also investigated the functional role of neural circuit for olfactory working memory in PD mice.Meanwhile,the excitatory post synaptic currents were decreased as a result of presynaptic release proba-bility suppression in PD mice.However cell loss wasn't found in working memory related circuit recently.These will provide a new idea of clinic diagnosis for PD.

Dissecting the role of subicular circuit in temporal lobe epilepsy / 中国药理学与毒理学杂志

OBJECTIVE Epilepsy is considered a cir-cuit-level dysfunction associated with imbalanced excita-tion-inhibition,it is therapeutically necessary to identify key brain regions and related circuits in epilepsy.The subic-ulum is an essential participant in epileptic seizures,but the circuit mechanism underlying its role remains largely elusive.METHODS Here we deconstruct the diversity of subicular circuits in mouse models of epilepsy.Fiber pho-tometry was used to detect intrinsic activities of subicular PV,SST-positive interneurons and CaMK Ⅱ α-positive pyramidal neurons.Optogenetics and chemogenetics were used to selectively active or inactive subicular neu-rons or their projecting terminals.We also used in vivo and in vitro electrophysiology to record membrane charac-teristics of single neuron in distinct sub-regions of the subiculum.Finally,single pulse test was used to detect synaptic transmission strength between the subiculum and its downstream target.RESULTS First,we found that two majority of subicular interneurons,which inner-vate local pyramidal neurons to constrain their excitability,PV and SST-positive neurons showcase distinct calcium dynamics during hippocampal seizures.This could be attributed to distinct neural inputs from para-hippocampal regions of these two neuronal types.During epileptogen-esis,PV and SST neurons undergo different circuit reor-ganization patterns,that is,remarkable increase of exter-nal input to subicular PV neurons are seen after seizures,while SST cells receive decimated neural input.As their downstream targets,excitatory subicular pyramidal neu-rons are also intrinsically activated during hippocampal seizures.Moreover,we found that the subiculum hetero-geneously controls the generalization of hippocampal sei-zures by projecting to different downstream regions.No-tably,anterior thalamus projecting subicular neurons bidi-rectionally mediate seizures,while entorhinal cortex-pro-jecting subicular neurons act oppositely in seizure modu-lation.These two subpopulations are structurally and functionally dissociable.An intrinsically enhanced hyper-polarization-activated current and robust bursting intensity in anterior thalamus-projecting neurons facilitate synaptic transmission,thus contributing to the generalization of hippocampal seizures.CONCLUSION These results demonstrate that subicular neurons and circuits have diverse roles in epilepsy,suggesting the necessity to pre-cisely target specific subicular circuits for effective treat-ment of epilepsy.

Regulation of the non-image-forming visual circuit on physiological activity and behavior / 中华实验眼科杂志

Retinal ganglion cells (RGCs) are final output neurons from the retina to the brain, which can transmit light signals and participate in image-forming vision (IFV) (image formation) and non-image-forming vision (NIFV) (non-image formation). Visual processing system not only transmits visual information of images, but also influences human physiological activities and behaviors by incoming optical signals, which is called NIFV.NIFV relies less on signals generated by conventional photoreceptor cells, but a special class of intrinsically photosensitive retinal ganglion cells (ipRGCs). ipRGCs are a subset of retinal ganglion cells that express melanopsin.The axons of the ipRGCs project to unique targets and modulate a broad range of NIFV behaviors, from basic physiological regulation (such as heart rate and pupil size) to more complex behavioral regulation (such as circadian rhythm) and even higher-level cognitive processes (such as anxiety and other emotions). NIFV circuit is an important response to light, and ipRGCs plays a vital role in NIFV circuit.This article reviewed the regulation of NIFV circuit in physiological activities and behaviors, summarized the relationship between the projections of ipRGCs to the NIFV function, and provided ophthalmologists with more knowledge of visual system.

Study on the difference of high frequency dielectric properties of biological tissues measured by air and packed coaxial probe / 生物医学工程学杂志

In this paper, the differences between air probe and filled probe for measuring high-frequency dielectric properties of biological tissues are investigated based on the equivalent circuit model to provide a reference for the methodology of high-frequency measurement of biological tissue dielectric properties. Two types of probes were used to measure different concentrations of NaCl solution in the frequency band of 100 MHz-2 GHz. The results showed that the accuracy and reliability of the calculated results of the air probe were lower than that of the filled probe, especially the dielectric coefficient of the measured material, and the higher the concentration of NaCl solution, the higher the error. By laminating the probe terminal, liquid intrusion could be prevented, to a certain extent, to improve the accuracy of measurement. However, as the frequency decreased, the influence of the film on the measurement increased and the measurement accuracy decreased. The results of the study show that the air probe, despite its simple dimensional design and easy calibration, differs from the conventional equivalent circuit model in actual measurements, and the model needs to be re-corrected for actual use. The filled probe matches the equivalent circuit model better, and therefore has better measurement accuracy and reliability.

Neuronal guidance genes in health and diseases

Neurons migrate from their birthplaces to the destinations, and extending axons navigate to their synaptic targets by sensing various extracellular cues in spatiotemporally controlled manners. These evolutionally conserved guidance cues and their receptors regulate multiple aspects of neural development to establish the highly complex nervous system by mediating both short- and long-range cell-cell communications. Neuronal guidance genes (encoding cues, receptors, or downstream signal transducers) are critical not only for development of the nervous system but also for synaptic maintenance, remodeling, and function in the adult brain. One emerging theme is the combinatorial and complementary functions of relatively limited classes of neuronal guidance genes in multiple processes, including neuronal migration, axonal guidance, synaptogenesis, and circuit formation. Importantly, neuronal guidance genes also regulate cell migration and cell-cell communications outside the nervous system. We are just beginning to understand how cells integrate multiple guidance and adhesion signaling inputs to determine overall cellular/subcellular behavior and how aberrant guidance signaling in various cell types contributes to diverse human diseases, ranging from developmental, neuropsychiatric, and neurodegenerative disorders to cancer metastasis. We review classic studies and recent advances in understanding signaling mechanisms of the guidance genes as well as their roles in human diseases. Furthermore, we discuss the remaining challenges and therapeutic potentials of modulating neuronal guidance pathways in neural repair.

Neural Circuit Mechanisms Involved in Animals' Detection of and Response to Visual Threats / 神经科学通报·英文版

Evading or escaping from predators is one of the most crucial issues for survival across the animal kingdom. The timely detection of predators and the initiation of appropriate fight-or-flight responses are innate capabilities of the nervous system. Here we review recent progress in our understanding of innate visually-triggered defensive behaviors and the underlying neural circuit mechanisms, and a comparison among vinegar flies, zebrafish, and mice is included. This overview covers the anatomical and functional aspects of the neural circuits involved in this process, including visual threat processing and identification, the selection of appropriate behavioral responses, and the initiation of these innate defensive behaviors. The emphasis of this review is on the early stages of this pathway, namely, threat identification from complex visual inputs and how behavioral choices are influenced by differences in visual threats. We also briefly cover how the innate defensive response is processed centrally. Based on these summaries, we discuss coding strategies for visual threats and propose a common prototypical pathway for rapid innate defensive responses.

Hippocampus: Molecular, Cellular, and Circuit Features in Anxiety / 神经科学通报·英文版

Anxiety disorders are currently a major psychiatric and social problem, the mechanisms of which have been only partially elucidated. The hippocampus serves as a major target of stress mediators and is closely related to anxiety modulation. Yet so far, its complex anatomy has been a challenge for research on the mechanisms of anxiety regulation. Recent advances in imaging, virus tracking, and optogenetics/chemogenetics have permitted elucidation of the activity, connectivity, and function of specific cell types within the hippocampus and its connected brain regions, providing mechanistic insights into the elaborate organization of the hippocampal circuitry underlying anxiety. Studies of hippocampal neurotransmitter systems, including glutamatergic, GABAergic, cholinergic, dopaminergic, and serotonergic systems, have contributed to the interpretation of the underlying neural mechanisms of anxiety. Neuropeptides and neuroinflammatory factors are also involved in anxiety modulation. This review comprehensively summarizes the hippocampal mechanisms associated with anxiety modulation, based on molecular, cellular, and circuit properties, to provide tailored targets for future anxiety treatment.

Thalamocortical Circuit Controls Neuropathic Pain via Up-regulation of HCN2 in the Ventral Posterolateral Thalamus / 神经科学通报·英文版

The thalamocortical (TC) circuit is closely associated with pain processing. The hyperpolarization-activated cyclic nucleotide-gated (HCN) 2 channel is predominantly expressed in the ventral posterolateral thalamus (VPL) that has been shown to mediate neuropathic pain. However, the role of VPL HCN2 in modulating TC circuit activity is largely unknown. Here, by using optogenetics, neuronal tracing, electrophysiological recordings, and virus knockdown strategies, we showed that the activation of VPL TC neurons potentiates excitatory synaptic transmission to the hindlimb region of the primary somatosensory cortex (S1HL) as well as mechanical hypersensitivity following spared nerve injury (SNI)-induced neuropathic pain in mice. Either pharmacological blockade or virus knockdown of HCN2 (shRNA-Hcn2) in the VPL was sufficient to alleviate SNI-induced hyperalgesia. Moreover, shRNA-Hcn2 decreased the excitability of TC neurons and synaptic transmission of the VPL-S1HL circuit. Together, our studies provide a novel mechanism by which HCN2 enhances the excitability of the TC circuit to facilitate neuropathic pain.

An Anterior Cingulate Cortex-to-Midbrain Projection Controls Chronic Itch in Mice / 神经科学通报·英文版

Itch is an unpleasant sensation that provokes the desire to scratch. While acute itch serves as a protective system to warn the body of external irritating agents, chronic itch is a debilitating but poorly-treated clinical disease leading to repetitive scratching and skin lesions. However, the neural mechanisms underlying the pathophysiology of chronic itch remain mysterious. Here, we identified a cell type-dependent role of the anterior cingulate cortex (ACC) in controlling chronic itch-related excessive scratching behaviors in mice. Moreover, we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area (VTA) that was critically involved in chronic itch. Furthermore, we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch. Finally, the ACC neurons were shown to predominantly innervate the non-dopaminergic neurons of the VTA. Taken together, our findings uncover a cortex-midbrain circuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.

Control of Emotion and Wakefulness by Neurotensinergic Neurons in the Parabrachial Nucleus / 神经科学通报·英文版

The parabrachial nucleus (PBN) integrates interoceptive and exteroceptive information to control various behavioral and physiological processes including breathing, emotion, and sleep/wake regulation through the neural circuits that connect to the forebrain and the brainstem. However, the precise identity and function of distinct PBN subpopulations are still largely unknown. Here, we leveraged molecular characterization, retrograde tracing, optogenetics, chemogenetics, and electrocortical recording approaches to identify a small subpopulation of neurotensin-expressing neurons in the PBN that largely project to the emotional control regions in the forebrain, rather than the medulla. Their activation induces freezing and anxiety-like behaviors, which in turn result in tachypnea. In addition, optogenetic and chemogenetic manipulations of these neurons revealed their function in promoting wakefulness and maintaining sleep architecture. We propose that these neurons comprise a PBN subpopulation with specific gene expression, connectivity, and function, which play essential roles in behavioral and physiological regulation.

Basal Forebrain Cholinergic Innervation Induces Depression-Like Behaviors Through Ventral Subiculum Hyperactivation / 神经科学通报·英文版

Malfunction of the ventral subiculum (vSub), the main subregion controlling the output connections from the hippocampus, is associated with major depressive disorder (MDD). Although the vSub receives cholinergic innervation from the medial septum and diagonal band of Broca (MSDB), whether and how the MSDB-to-vSub cholinergic circuit is involved in MDD is elusive. Here, we found that chronic unpredictable mild stress (CUMS) induced depression-like behaviors with hyperactivation of vSub neurons, measured by c-fos staining and whole-cell patch-clamp recording. By retrograde and anterograde tracing, we confirmed the dense MSDB cholinergic innervation of the vSub. In addition, transient restraint stress in CUMS increased the level of ACh in the vSub. Furthermore, chemogenetic stimulation of this MSDB-vSub innervation in ChAT-Cre mice induced hyperactivation of vSub pyramidal neurons along with depression-like behaviors; and local infusion of atropine, a muscarinic receptor antagonist, into the vSub attenuated the depression-like behaviors induced by chemogenetic stimulation of this pathway and CUMS. Together, these findings suggest that activating the MSDB-vSub cholinergic pathway induces hyperactivation of vSub pyramidal neurons and depression-like behaviors, revealing a novel circuit underlying vSub pyramidal neuronal hyperactivation and its associated depression.