imaging AND awake

Positron emission tomography (PET) imaging studies in laboratory animals are almost always performed under isoflurane anesthesia to ensure that the subject stays still during the image acquisition. Isoflurane is effective, safe, and easy to use, and it is generally assumed to not have an impact on the imaging results. Motivated by marked differences observed in the brain uptake and metabolism of the PET tracer 3-[18 F]fluoro-4-aminopyridine [(18 F]3F4AP) between human and nonhuman primate studies, this study investigates the possible effect of isoflurane on this process...

INTRODUCTION: Peripheral sensory neurons serve as the initial responders to the external environment. How these neurons react to different sensory stimuli, such as mechanical or thermal forces applied to the skin, remains unclear. METHODS: Using in vivo two-photon Ca2+ imaging in the lumbar 4 dorsal root ganglion (DRG) of awake Thy1.2 -GCaMP6s mice, we assessed neuronal responses to various mechanical (punctate or dynamic) and thermal forces (heat or cold) sequentially applied to the paw plantar surface...

Over the years, possibilities in ankle arthroscopy have evolved from diagnostic inspection to complex interventional procedures. Further innovation may come from needle arthroscopy, which has improved substantially in image quality in recent years and can now be used for interventional procedures as well. We here present a standardized approach to wide-awake needle arthroscopy of the anterior ankle under local anesthesia. As new needle arthroscopic procedures of the ankle arise, this approach serves to help ensure safe, uniform, and beneficial adoption of this emergent technique...

Despite substantial progress in mapping the trajectory of network plasticity resulting from focal ischemic stroke, the extent and nature of changes in neuronal excitability and activity within the peri-infarct cortex of mice remains poorly defined. Most of the available data have been acquired from anesthetized animals, acute tissue slices, or infer changes in excitability from immunoassays on extracted tissue, and thus may not reflect cortical activity dynamics in the intact cortex of an awake animal. Here, in vivo two-photon calcium imaging in awake, behaving mice was used to longitudinally track cortical activity, network functional connectivity, and neural assembly architecture for 2 months following photothrombotic stroke targeting the forelimb somatosensory cortex...

A-scan ultrasonography enables precise measurement of internal ocular structures. Historically, its use has underpinned fundamental studies of eye development and aberrant eye growth in animal models of myopia; however, the procedure typically requires anaesthesia. Since anaesthesia affects intra-ocular pressure (IOP), we investigated changes in internal ocular structures with isoflurane exposure and compared measurements with those taken in awake animals using optical coherence tomography (OCT). Continuous A-scan ultrasonography was undertaken in tri-coloured guinea pigs aged 21 (n = 5), 90 (n = 5) or 160 (n = 5) days while anaesthetised (up to 36 mins) with isoflurane (5% in 1...

To prevent motion artifacts in small animal positron emission tomography (PET), animals are routinely scanned under anesthesia or physical restraint. Both may potentially alter metabolism and neurochemistry. This study investigates the feasibility of fully awake acquisition and subsequent absolute quantification of dynamic brain PET data via pharmacokinetic modelling in moving rats using the glutamate 5 receptor radioligand [11 C]ABP688 and point source based motion correction. Five male rats underwent three dynamic [11 C]ABP688 PET scans: two test-retest awake PET scans and one scan under anesthesia for comparison...

Electrical stimulation provides a clinically viable approach for treating neurological disorders. Here, we present a protocol for recording neural activity evoked by electrical stimulation in mice using two-photon calcium imaging. We detail steps for chronically implanting a head fixation bar, a stimulating electrode, and a glass imaging window. We additionally describe the procedures for viral injections and awake head-fixed recordings. For complete details on the use and execution of this protocol, please refer to Dadarlat et al...

The introduction of minimally invasive surgery ushered in a new era of spine surgery by minimizing the undue iatrogenic injury, recovery time, and blood loss, among other complications, of traditional open procedures. Over time, technological advancements have further refined the care of the operative minimally invasive spine patient. Moreover, pre-, and postoperative care have also undergone significant change by way of artificial intelligence risk stratification, advanced imaging for surgical planning and patient selection, postoperative recovery pathways, and digital health solutions...

Lewy Body Dementias (LBD), including Parkinson's disease dementia and Dementia with Lewy Bodies, are characterized by widespread accumulation of intracellular alpha-Synuclein protein deposits in regions beyond the brainstem, including in the cortex. However, the impact of local pathology in the cortex is unknown. To investigate this, we employed viral overexpression of human alpha-Synuclein protein targeting the mouse prefrontal cortex (PFC). We then used in vivo 2-photon microscopy to image awake head-fixed mice via an implanted chronic cranial window to assess the early consequences of alpha-Synuclein overexpression in the weeks following overexpression...

Afferent neurons in developing sensory organs exhibit a prolonged period of burst firing prior to the onset of sensory experience. This intrinsically generated activity propagates from the periphery through central processing centers to promote the survival and physiological maturation of neurons and refine their synaptic connectivity. Recent studies in the auditory system indicate that these bursts of action potentials also trigger metabotropic glutamate receptor-mediated calcium increases within astrocytes that are spatially and temporally correlated with neuronal events; however, it is not known if this phenomenon occurs in other sensory modalities...

Social communication draws on several cognitive functions such as perception, emotion recognition and attention. The association of audio-visual information is essential to the processing of species-specific communication signals. In this study, we use functional magnetic resonance imaging in order to identify the subcortical areas involved in the cross-modal association of visual and auditory information based on their common social meaning. We identified three subcortical regions involved in audio-visual processing of species-specific communicative signals: the dorsolateral amygdala, the claustrum and the pulvinar...

SIGNIFICANCE: Advances in genetically encoded sensors and two-photon imaging have unlocked functional imaging at the level of single dendritic spines. Synaptic activity can be measured in real time in awake animals. However, tools are needed to facilitate the analysis of the large datasets acquired by the approach. Commonly available software suites for imaging calcium transients in cell bodies are ill-suited for spine imaging as dendritic spines have structural characteristics distinct from those of the cell bodies...

Resting state networks (RSNs) are increasingly forwarded as candidate biomarkers for neuropsychiatric disorders. Such biomarkers may provide objective measures for evaluating novel therapeutic interventions in nonhuman primates often used in translational neuroimaging research. This study aimed to characterize the RSNs of awake squirrel monkeys and compare the characteristics of those networks in adolescent and adult subjects. Twenty-seven squirrel monkeys ( n =12 adolescents [6 male/6 female] ∼2.5 years and n =15 adults [7 male/8 female] ∼9...

OBJECTIVE: The free-water correction algorithm (Freewater Estimator Using Interpolated Initialization [FERNET]) can be applied to standard diffusion tensor imaging (DTI) tractography to improve visualization of subcortical bundles in the peritumoral area of highly edematous brain tumors. Interest in its use for presurgical planning in purely infiltrative gliomas without peritumoral edema has never been evaluated. Using subcortical maps obtained with direct electrostimulation (DES) in awake surgery as a reference standard, the authors sought to 1) assess the accuracy of preoperative DTI-based tractography with FERNET in a series of nonedematous glioma patients, and 2) determine its potential usefulness in presurgical planning...

Functional brain connectivity based on resting-state functional magnetic resonance imaging (fMRI) has been shown to be correlated with human personality and behavior. In this study, we sought to know whether capabilities and traits in dogs can be predicted from their resting-state connectivity, as in humans. We trained awake dogs to keep their head still inside a 3T MRI scanner while resting-state fMRI data was acquired. Canine behavior was characterized by an integrated behavioral score capturing their hunting, retrieving, and environmental soundness...

Neuronal ensembles are groups of neurons with correlated activity associated with sensory, motor, and behavioral functions. To explore how ensembles encode information, we investigated responses of visual cortical neurons in awake mice using volumetric two-photon calcium imaging during visual stimulation. We identified neuronal ensembles employing an unsupervised model-free algorithm and, besides neurons activated by the visual stimulus (termed "onsemble"), we also find neurons that are specifically inactivated (termed "offsemble")...

Mediastinal masses pose one of the great challenges for any anesthesiologist during airway maintenance, underlining the need to devise a well-formulated plan to avoid perioperative complications. As a general rule, such patients are managed with spontaneous ventilation without the use of muscle relaxants and awake intubation. We report a case of a 66-year-old male with severe dyspnea, having a very large invasive anterior mediastinal mass, causing left lung collapse for urgent debulking surgery. The tracheobronchial compromise was ruled out using three-dimensional reconstruction on computed tomography imaging (virtual bronchoscopy) and that helped in using general anesthesia with muscle relaxation for subsequent endotracheal intubation and surgery...

BACKGROUND: Patients with Parkinson's Disease (PD) who receive either asleep image-guided subthalamic nucleus deep brain stimulation (DBS) or the traditional awake technique have comparable motor outcomes. However, there are fewer studies regarding which technique should be chosen for globus pallidus internus (GPi) DBS. This systematic review and meta-analysis aims to compare the accuracy of lead placement and motor outcomes of asleep versus awake GPi DBS PD population. METHODS: We systematically searched PubMed, Embase, and Cochrane for studies comparing asleep vs...

Nick is a 5-year-old boy who began displaying self-stimulating behaviors and decreased social interactions shortly before turning 3 years. At the age of 3.5 years, he was diagnosed with autism spectrum disorder by a local developmental-behavioral pediatrician. His parents recall that the physician described Nick to be "high functioning" and encouraged them to expect that he would attend college and live independently as an adult. Upon receiving the diagnosis, intervention was initiated using an applied behavioral analysis (ABA) approach...

Urinary bladder volume (UBV) can be estimated using point-of-care ultrasound. The purpose of this study was to compare 2 UBV estimation methods, i.e ., three-dimensional (3D) bladder circumference tracing and 2-dimensional (2D) linear bladder dimension formula, against actual bladder volumes in awake client-owned cats and identify the best scanning position for UBV estimations. Up to 3 paired sets of orthogonal longitudinal and transverse bladder ultrasound images were acquired by a trained clinician from 21 cats positioned in dorsal, right lateral, and left lateral recumbency...