CFANet: Context Feature Fusion and Attention Mechanism Based Network for Small Target Segmentation in Medical Images.

Medical image segmentation plays a crucial role in clinical diagnosis, treatment planning, and disease monitoring. The automatic segmentation method based on deep learning has developed rapidly, with segmentation results comparable to clinical experts for large objects, but the segmentation accuracy for small objects is still unsatisfactory. Current segmentation methods based on deep learning find it difficult to extract multiple scale features of medical images, leading to an insufficient detection capability for smaller objects. In this paper, we propose a context feature fusion and attention mechanism based network for small target segmentation in medical images called CFANet. CFANet is based on U-Net structure, including the encoder and the decoder, and incorporates two key modules, context feature fusion (CFF) and effective channel spatial attention (ECSA), in order to improve segmentation performance. The CFF module utilizes contextual information from different scales to enhance the representation of small targets. By fusing multi-scale features, the network captures local and global contextual cues, which are critical for accurate segmentation. The ECSA module further enhances the network's ability to capture long-range dependencies by incorporating attention mechanisms at the spatial and channel levels, which allows the network to focus on information-rich regions while suppressing irrelevant or noisy features. Extensive experiments are conducted on four challenging medical image datasets, namely ADAM, LUNA16, Thoracic OAR, and WORD. Experimental results show that CFANet outperforms state-of-the-art methods in terms of segmentation accuracy and robustness. The proposed method achieves excellent performance in segmenting small targets in medical images, demonstrating its potential in various clinical applications.

Multiplexed Representation of Itch and Mechanical and Thermal Sensation in the Primary Somatosensory Cortex.

The primary somatosensory cortex (S1) plays a critical role in processing multiple somatosensations, but the mechanism underlying the representation of different submodalities of somatosensation in S1 remains unclear. Using in vivo two-photon calcium imaging that simultaneously monitors hundreds of layer 2/3 pyramidal S1 neurons of awake male mice, we examined neuronal responses triggered by mechanical, thermal, or pruritic stimuli. We found that mechanical, thermal, and pruritic stimuli activated largely overlapping neuronal populations in the same somatotopic S1 subregion. Population decoding analysis revealed that the local neuronal population in S1 encoded sufficient information to distinguish different somatosensory submodalities. Although multimodal S1 neurons responding to multiple types of stimuli exhibited no spatial clustering, S1 neurons preferring mechanical and thermal stimuli tended to show local clustering. These findings demonstrated the coding scheme of different submodalities of somatosensation in S1, paving the way for a deeper understanding of the processing and integration of multimodal somatosensory information in the cortex.SIGNIFICANCE STATEMENT Cortical processing of somatosensory information is one of the most fundamental aspects in cognitive neuroscience. Previous studies mainly focused on mechanical sensory processing within the rodent whisking system, but mechanisms underlying the coding of multiple somatosensations remain largely unknown. In this study, we examined the representation of mechanical, thermal, and pruritic stimuli in S1 by in vivo two-photon calcium imaging of awake mice. We revealed a multiplexed representation for multiple somatosensory stimuli in S1 and demonstrated that the activity of a small population of S1 neurons is capable of decoding different somatosensory submodalities. Our results elucidate the coding mechanism for multiple somatosensations in S1 and provide new insights that improve the present understanding of how the brain processes multimodal sensory information.

Nonlinear dendritic integration of sensory and motor input during an active sensing task.

Active dendrites provide neurons with powerful processing capabilities. However, little is known about the role of neuronal dendrites in behaviourally related circuit computations. Here we report that a novel global dendritic nonlinearity is involved in the integration of sensory and motor information within layer 5 pyramidal neurons during an active sensing behaviour. Layer 5 pyramidal neurons possess elaborate dendritic arborizations that receive functionally distinct inputs, each targeted to spatially separate regions. At the cellular level, coincident input from these segregated pathways initiates regenerative dendritic electrical events that produce bursts of action potential output and circuits featuring this powerful dendritic nonlinearity can implement computations based on input correlation. To examine this in vivo we recorded dendritic activity in layer 5 pyramidal neurons in the barrel cortex using two-photon calcium imaging in mice performing an object-localization task. Large-amplitude, global calcium signals were observed throughout the apical tuft dendrites when active touch occurred at particular object locations or whisker angles. Such global calcium signals are produced by dendritic plateau potentials that require both vibrissal sensory input and primary motor cortex activity. These data provide direct evidence of nonlinear dendritic processing of correlated sensory and motor information in the mammalian neocortex during active sensation.

Activity in motor-sensory projections reveals distributed coding in somatosensation.

Cortical-feedback projections to primary sensory areas terminate most heavily in layer 1 (L1) of the neocortex, where they make synapses with tuft dendrites of pyramidal neurons. L1 input is thought to provide 'contextual' information, but the signals transmitted by L1 feedback remain uncharacterized. In the rodent somatosensory system, the spatially diffuse feedback projection from vibrissal motor cortex (vM1) to vibrissal somatosensory cortex (vS1, also known as the barrel cortex) may allow whisker touch to be interpreted in the context of whisker position to compute object location. When mice palpate objects with their whiskers to localize object features, whisker touch excites vS1 and later vM1 in a somatotopic manner. Here we use axonal calcium imaging to track activity in vM1-->vS1 afferents in L1 of the barrel cortex while mice performed whisker-dependent object localization. Spatially intermingled individual axons represent whisker movements, touch and other behavioural features. In a subpopulation of axons, activity depends on object location and persists for seconds after touch. Neurons in the barrel cortex thus have information to integrate movements and touches of multiple whiskers over time, key components of object identification and navigation by active touch.

Imaging neuronal populations in behaving rodents: paradigms for studying neural circuits underlying behavior in the mammalian cortex.

Understanding the neural correlates of behavior in the mammalian cortex requires measurements of activity in awake, behaving animals. Rodents have emerged as a powerful model for dissecting the cortical circuits underlying behavior attributable to the convergence of several methods. Genetically encoded calcium indicators combined with viral-mediated or transgenic tools enable chronic monitoring of calcium signals in neuronal populations and subcellular structures of identified cell types. Stable one- and two-photon imaging of neuronal activity in awake, behaving animals is now possible using new behavioral paradigms in head-fixed animals, or using novel miniature head-mounted microscopes in freely moving animals. This mini-symposium will highlight recent applications of these methods for studying sensorimotor integration, decision making, learning, and memory in cortical and subcortical brain areas. We will outline future prospects and challenges for identifying the neural underpinnings of task-dependent behavior using cellular imaging in rodents.

Dynamic ensemble balance in direct- and indirect-pathway striatal projection neurons underlying decision-related action selection.

The posterior dorsal striatum (pDS) plays an essential role in sensory-guided decision-making. However, it remains unclear how the antagonizing direct- and indirect-pathway striatal projection neurons (dSPNs and iSPNs) work in concert to support action selection. Here, we employed deep-brain two-photon imaging to investigate pathway-specific single-neuron and population representations during an auditory-guided decision-making task. We found that the majority of pDS projection neurons predominantly encode choice information. Both dSPNs and iSPNs comprise divergent subpopulations of comparable sizes representing competing choices, rendering a multi-ensemble balance between the two pathways. Intriguingly, such ensemble balance displays a dynamic shift during the decision period: dSPNs show a significantly stronger preference for the contraversive choice than iSPNs. This dynamic shift is further manifested in the inter-neuronal coactivity and population trajectory divergence. Our results support a balance-shift model as a neuronal population mechanism coordinating the direct and indirect striatal pathways for eliciting selected actions during decision-making.

Misdiagnosis of hemangioma of left triangular ligament of the liver as gastric submucosal stromal tumor: Two case reports.

BACKGROUND: Extragastric lesions are typically not misdiagnosed as gastric submucosal tumor (SMT). However, we encountered two rare cases where extrinsic lesions were misdiagnosed as gastric SMTs. CASE SUMMARY: We describe two cases of gastric SMT-like protrusions initially misdiagnosed as gastric SMTs by the abdominal contrast-enhanced computed tomography (CT) and endoscopic ultrasound (EUS). Based on the CT and EUS findings, the patients underwent gastroscopy; however, no tumor was identified after incising the gastric wall. Subsequent surgical exploration revealed no gastric lesions in both patients, but a mass was found in the left triangular ligament of the liver. The patients underwent laparoscopic tumor resection, and the postoperative diagnosis was hepatic hemangiomas. CONCLUSION: During EUS procedures, scanning across different layers and at varying degrees of gastric cavity distension, coupled with meticulous image analysis, has the potential to mitigate the likelihood of such misdiagnoses.

Suppressing Structural Relaxation in Nanoscale Antimony to Enable Ultralow-Drift Phase-Change Memory Applications.

Phase-change random-access memory (PCRAM) devices suffer from pronounced resistance drift originating from considerable structural relaxation of phase-change materials (PCMs), which hinders current developments of high-capacity memory and high-parallelism computing that both need reliable multibit programming. This work realizes that compositional simplification and geometrical miniaturization of traditional GeSbTe-like PCMs are feasible routes to suppress relaxation. While to date, the aging mechanisms of the simplest PCM, Sb, at nanoscale, have not yet been unveiled. Here, this work demonstrates that in an optimal thickness of only 4 nm, the thin Sb film can enable a precise multilevel programming with ultralow resistance drift coefficients, in a regime of ≈10-4 -10-3 . This advancement is mainly owed to the slightly changed Peierls distortion in Sb and the less-distorted octahedral-like atomic configurations across the Sb/SiO2 interfaces. This work highlights a new indispensable approach, interfacial regulation of nanoscale PCMs, for pursuing ultimately reliable resistance control in aggressively-miniaturized PCRAM devices, to boost the storage and computing efficiencies substantially.

Reshaping sensory representations by task-specific brain states: Toward cortical circuit mechanisms.

Perception is internally constructed by integrating brain states with external sensory inputs, a process depending on the topdown modulation of sensory representations. A wealth of earlier studies described task-dependent modulations of sensory cortex corroborating perceptual and behavioral phenomena. But only with recent technological advancements, the underlying circuit-level mechanisms began to be unveiled. We review recent progress along this line of research. It begins to be appreciated that topdown signals can encode various types of task-related information, ranging from task engagement, and category knowledge to decision execution; these signals are transferred via feedback pathways originating from distinct association cortices and interact with sensory cortical circuits. These plausible mechanisms support a broad range of computations from predictive coding to inference making, ultimately form dynamic percepts and endow behavioral flexibility.

Focal white matter microstructural alteration after anthracycline-based systemic treatment in long-term breast cancer survivors: a structural magnetic resonance imaging study.

Understanding the neural correlates of cognitive problems in patients with breast cancer (BC) after systemic treatment have been a topic of increasing investigation. The heterogeneity of the systemic treatment regimens may undermine our ability to identify brain microstructural alterations resulting from any given regimen. We investigated the detrimental effects of the anthracycline-based systemic treatment (AST) regimen (epirubicin and cyclophosphamide + docetaxel + tamoxifen) on brain gray matter (GM) and white matter (WM) microstructural alteration in long-term BC survivors. We performed a battery of neuropsychological tests and structural magnetic resonance imaging (MRI) to 31 long-term BC survivors who had received the AST regimen (AST group) and 43 healthy controls (HC group). Voxel-based morphometry evaluated the whole-brain voxel-wise GM volume, while diffusion tensor imaging technique with tract-based spatial statistics analysis evaluated whole-brain WM microstructural alteration. Partial least squares regression (PLSR) was used to evaluate the relationship between cognitive impairment and brain microstructural alteration in BC survivors. Compared with the HC group, the AST group exhibited a significantly poorer performance in attention, as well as a marginal significantly poorer performance in verbal working memory and executive function. Significantly lower fractional anisotropy (FA), higher radial diffusivity (RD), and lower axial diffusivity (AD) in multiple brain WM regions were showed in AST group compared with the HC group. Overlap of lower FA and higher RD was found in the body of corpus callosum (CC) and bilateral superior corona radiata (SCR), whereas overlap of lower FA and AD was found in the body of CC and right SCR. The PLSR results showed that the WM regions with overlap of lower FA and AD were significantly associated with executive and verbal working memory decline. No significant difference was observed in the GM volume between groups. Our results suggest that microstructural abnormalities of certain vulnerable WM regions in the AST regimen-exposed brain may provide neuroimaging evidence for the identification of brain injury and cognitive impairment induced by specific chemotherapy regimens.

Itch perception is reflected by neuronal ignition in the primary somatosensory cortex.

Multiple cortical areas including the primary somatosensory cortex (S1) are activated during itch signal processing, yet cortical representation of itch perception remains unknown. Using novel miniature two-photon microscopic imaging in free-moving mice, we investigated the coding of itch perception in S1. We found that pharmacological inactivation of S1 abolished itch-induced scratching behavior, and the itch-induced scratching behavior could be well predicted by the activity of a fraction of layer 2/3 pyramidal neurons, suggesting that a subpopulation of S1 pyramidal neurons encoded itch perception, as indicated by immediate subsequent scratching behaviors. With a newly established optogenetics-based paradigm that allows precisely controlled pruritic stimulation, we found that a small fraction of S1 neurons exhibited an ignition-like pattern at the detection threshold of itch perception. Our study revealed the neural mechanism underlying itch perceptual coding in S1, thus paving the way for the study of cortical representation of itch perception at the single-neuron level in freely moving animals.

Disturbed microcirculation and hyperaemic response in a murine model of systemic inflammation.

Systemic inflammation affects cognitive functions and increases the risk of dementia. This phenomenon is thought to be mediated in part by cytokines that promote neuronal survival, but the continuous exposure to which may lead to neurodegeneration. The effects of systemic inflammation on cerebral blood vessels, and their provision of adequate oxygen to support critical brain parenchymal cell functions, remains unclear. Here, we demonstrate that neurovascular coupling is profoundly disturbed in lipopolysaccharide (LPS) induced systemic inflammation in awake mice. In the 24 hours following LPS injection, the hyperaemic response of pial vessels to functional activation was attenuated and delayed. Concurrently, under steady-state conditions, the capillary network displayed a significant increase in the number of capillaries with blocked blood flow, as well as increased duration of 'capillary stalls'-a phenomenon previously reported in animal models of stroke and Alzheimer's disease pathology. We speculate that vascular changes and impaired oxygen availability may affect brain functions following acute systemic inflammation and contribute to the long-term risk of neurodegenerative changes associated with chronic, systemic inflammation.

A cortical circuit mechanism for structural knowledge-based flexible sensorimotor decision-making.

Making flexible decisions based on prior knowledge about causal environmental structures is a hallmark of goal-directed cognition in mammalian brains. Although several association brain regions, including the orbitofrontal cortex (OFC), have been implicated, the precise neuronal circuit mechanisms underlying knowledge-based decision-making remain elusive. Here, we established an inference-based auditory categorization task where mice performed within-session flexible stimulus re-categorization by inferring the changing task rules. We constructed a reinforcement learning model to recapitulate the inference-based flexible behavior and quantify the hidden variables associated with task structural knowledge. Combining two-photon population imaging and projection-specific optogenetics, we found that auditory cortex (ACx) neurons encoded the hidden task rule variable, which requires feedback input from the OFC. Silencing OFC-ACx input specifically disrupted re-categorization behavior. Direct imaging from OFC axons in the ACx revealed task state-related feedback signals, supporting the knowledge-based updating mechanism. Our data reveal a cortical circuit mechanism underlying structural knowledge-based flexible decision-making.

A cortico-collicular pathway for motor planning in a memory-dependent perceptual decision task.

Survival in a dynamic environment requires animals to plan future actions based on past sensory evidence, known as motor planning. However, the neuronal circuits underlying this crucial brain function remain elusive. Here, we employ projection-specific imaging and perturbation methods to investigate the direct pathway linking two key nodes in the motor planning network, the secondary motor cortex (M2) and the midbrain superior colliculus (SC), in mice performing a memory-dependent perceptual decision task. We find dynamic coding of choice information in SC-projecting M2 neurons during motor planning and execution, and disruption of this information by inhibiting M2 terminals in SC selectively impaired decision maintenance. Furthermore, we show that while both excitatory and inhibitory SC neurons receive synaptic inputs from M2, these SC subpopulations display differential temporal patterns in choice coding during behavior. Our results reveal the dynamic recruitment of the premotor-collicular pathway as a circuit mechanism for motor planning.

Deciphering Pyramidal Neuron Diversity: Delineating Perceptual Functions of Projection-Defined Neuronal Types.

Axonal projection patterns are increasingly recognized as a defining feature for neuronal classification. How could such structural distinctions be linked to functions? In this issue of Neuron, Tang and Higley (2020) disambiguate behavior-level functions of two projection-defined subtypes of cortical projection neurons.

Esophageal bronchogenic cyst excised by endoscopic submucosal tunnel dissection: A case report.

BACKGROUND: Esophageal bronchogenic cyst (EBC) is a rare congenital disease that is difficult to diagnose preoperatively, and treatment remains controversial. CASE SUMMARY: We report a 53-year-old Chinese woman hospitalized in our hospital following the discovery of a submucosal protruding mass of the esophagus by upper endoscopy. A preliminary diagnosis of EBC was made by endoscopic ultrasonography (EUS), and treatment was accomplished by endoscopic submucosal tunnel dissection (ESTD). The pathological results verified the diagnosis. No scar changes or cystic lesion within the original lesion were found under EUS after a 3-mo follow-up. CONCLUSION: EUS is valuable for the preliminary diagnosis of EBC and surveillance. ESTD is a safe and effective treatment for EBC. Further evaluation of complications and long-term follow-ups are required.

Giant laryngeal angioleiomyomas: a case report with review of literature.

We report a recently encountered case of vascular leiomyoma in the larynx, a benign tumor that is rare in the organ, in a 52-year-old man. Chief complaints were a progressive hoarseness, laryngeal pain, deglutitive uncomfortableness and dyspnea in the supine position. Laryngoscope revealed many spherical tumors interlacing together with a smooth surface, measuring approximately 2x4 cm and covered with normal mucosa, found at the side of laryngeal epiglottis from its margin to supraglottis. Tracheotomy was performed under local anesthesia, and laryngosurgery was then carried out under general anesthesia. Histologic study showed smooth muscle cell proliferation, especially surrounded by an abundance of blood vessels, and the tumor was diagnosed as a vascular leiomyoma. Its complete resection was the best therapeutic option. Tracheotomy was required in this case depending on the occurrence site if the tumor and its size.

Multiple gastric angiolipomas: A case report.

BACKGROUND: Angiolipoma is a benign tumor and is generally found in subcutaneous tissues. Angiolipomas are rare in the gastrointestinal tract, including the stomach. Preoperative diagnosis of the tumor is difficult, although there are several radiological examinations such as computed tomography and endoscopic ultrasound. CASE SUMMARY: We report a 24-year-old Chinese man with multiple gastric angiolipomas, with a positive stool occult blood examination. Endoscopic biopsy only showed nonspecific inflammation. Histological examination of the specimen by endoscopic snare resection showed that the tumor consisted of adipose tissues and blood vessels. We also performed a literature review. After the use of proton pump inhibitor, the fecal occult blood test was negative. Due to the difficulty of resecting multiple lesions in the stomach completely and the benign characteristics of angiolipoma, we chose to have regular upper gastrointestinal endoscopy evaluation of the lesion. No evidence of significant change in lesion size was detected after 3-years follow-up. CONCLUSION: Gastric angiolipoma is rare, and benign neoplasm should be considered when lesions occur submucosally in the gastrointestinal tract.