RESUMEN
The recent publications of the inter-areal connectomes for mouse, marmoset, and macaque cortex have allowed deeper comparisons across rodent vs. primate cortical organization. In general, these show that the mouse has very widespread, "all-to-all" inter-areal connectivity (i.e. a "highly dense" connectome in a graph theoretical framework), while primates have a more modular organization. In this review, we highlight the relevance of these differences to function, including the example of primary visual cortex (V1) which, in the mouse, is interconnected with all other areas, therefore including other primary sensory and frontal areas. We argue that this dense inter-areal connectivity benefits multimodal associations, at the cost of reduced functional segregation. Conversely, primates have expanded cortices with a modular connectivity structure, where V1 is almost exclusively interconnected with other visual cortices, themselves organized in relatively segregated streams, and hierarchically higher cortical areas such as prefrontal cortex provide top-down regulation for specifying precise information for working memory storage and manipulation. Increased complexity in cytoarchitecture, connectivity, dendritic spine density, and receptor expression additionally reveal a sharper hierarchical organization in primate cortex. Together, we argue that these primate specializations permit separable deconstruction and selective reconstruction of representations, which is essential to higher cognition.
Asunto(s)
Callithrix , Cognición , Conectoma , Macaca , Animales , Ratones , Cognición/fisiología , Red Nerviosa/fisiología , Vías Nerviosas/fisiología , Corteza Cerebral/fisiologíaRESUMEN
PURPOSE: More women diagnosed with breast cancer (BC) are living with oncology treatment-induced hot flushes (HFs). This Australian-based survey explores why some women experience more severe or ongoing HF and whether specific population characteristics are predictive of HF occurrence, frequency, and/or severity. METHODS: A non-probabilistic anonymous survey distributed online (Register4) and two Australian hospitals collected demographic and clinical information. Eligibility was consenting Australian-based women, 18 years and over, with a primary BC diagnosis. Analysis included linear and logistic regression models. RESULTS: A total of 324 survey responses were analyzed. Chemotherapy and hormone therapy were each associated with HF occurrence (aOR = 2.92, 95% CI [1.27, 6.70], p = 0.01; and aOR = 7.50, 95% CI [3.02, 18.62], p < 0.001) and in combination (aOR = 5.98, 95% CI [2.61, 13.69], p < 0.001). Increased self-reported anxiety at BC diagnosis was significantly associated with HF frequency and severity scores (aCO = 0.71, 95% CI [0.31, 1.12], p = 0.001; and aCO = 0.44, 95% CI [0.33, 0.55], p < 0.001). Postmenopausal women had significantly lower HF severity and frequency scores than premenopausal women (aCO = -0.93, 95% CI [-1.62, -0.25], p = 0.008; and aCO = -2.62, 95% CI [-5.14, -0.11], p = 0.041). CONCLUSIONS: Women with BC receiving chemotherapy and/or hormone therapy and premenopausal or experiencing elevated anxiety and/or stress will likely experience more severe oncology treatment-related HFs. IMPLICATIONS FOR CANCER SURVIVORS: HFs continue across the BC treatment trajectory with women >5-year survivorship still reporting life impacts, with premenopausal women at the time of BC diagnosis at higher risk of experiencing severe and more frequent oncology treatment-induced HFs than postmenopausal women. Women at high risk require information on methods to moderate HF potential life impacts and maintain treatment compliance.
RESUMEN
Recent advances in connectomics and neurophysiology make it possible to probe whole-brain mechanisms of cognition and behavior. We developed a large-scale model of the multiregional mouse brain for a cardinal cognitive function called working memory, the brain's ability to internally hold and process information without sensory input. The model is built on mesoscopic connectome data for interareal cortical connections and endowed with a macroscopic gradient of measured parvalbumin-expressing interneuron density. We found that working memory coding is distributed yet exhibits modularity; the spatial pattern of mnemonic representation is determined by long-range cell type-specific targeting and density of cell classes. Cell type-specific graph measures predict the activity patterns and a core subnetwork for memory maintenance. The model shows numerous attractor states, which are self-sustained internal states (each engaging a distinct subset of areas). This work provides a framework to interpret large-scale recordings of brain activity during cognition, while highlighting the need for cell type-specific connectomics.
Asunto(s)
Conectoma , Memoria a Corto Plazo , Animales , Ratones , Memoria a Corto Plazo/fisiología , Encéfalo/fisiología , Cognición/fisiología , Imagen por Resonancia MagnéticaRESUMEN
The somatosensory cortex is a brain region responsible for receiving and processing sensory information from across the body and is structurally and functionally heterogeneous. Since the chemoarchitectonic segregation of the cerebral cortex can be revealed by transmitter receptor distribution patterns, by using a quantitative multireceptor architectonical analysis, we determined the number and extent of distinct areas of the macaque somatosensory cortex. We identified three architectonically distinct cortical entities within the primary somatosensory cortex (i.e., 3bm, 3bli, 3ble), four within the anterior parietal cortex (i.e., 3am, 3al, 1 and 2) and six subdivisions (i.e., S2l, S2m, PVl, PVm, PRl and PRm) within the lateral fissure. We provide an ultra-high resolution 3D atlas of macaque somatosensory areas in stereotaxic space, which integrates cyto- and receptor architectonic features of identified areas. Multivariate analyses of the receptor fingerprints revealed four clusters of identified areas based on the degree of (dis)similarity of their receptor architecture. Each of these clusters can be associated with distinct levels of somatosensory processing, further demonstrating that the functional segregation of cortical areas is underpinned by differences in their molecular organization.
Asunto(s)
Mapeo Encefálico , Corteza Somatosensorial , Animales , Corteza Somatosensorial/fisiología , Macaca , Masculino , Macaca mulattaRESUMEN
BACKGROUND: People living with a cancer diagnosis often experience cancer-related fatigue (CRF). Between 9% and 45% of people report CRF as moderate to severe, negatively impacting their quality-of-life (QOL). The evidence-base for managing CRF recommends exercise-related therapies over pharmaceutical interventions. One such exercise-like therapy is Baduanjin mind-body exercise (MBE), which has additional benefits. A remotely delivered program may further benefit people with CRF. The primary objective of this pilot will test study feasibility of a remotely delivered Baduanjin MBE exercise program for people living with CRF. METHODS: This is a randomized wait-list controlled pilot study and will take place in Sydney, Australia. Subject to informed consent, 40 adults with moderate CRF levels and receiving or previously received adjuvant chemotherapy, will undertake a home-based 8-week Baduanjin MBE program supported by online resources and instructors. The primary feasibility outcomes are recruitment, enrollment, retention, and adherence rates; and safety as measured by tolerance and adverse-event frequency. Clinical outcomes (eg, changes in CRF, QOL, and participant perceptions) are assessed at pre-intervention, week 1, week 4, week 8, and post-intervention. Analyses follows the Intent-to-Treat (all participants as per randomization) and per-protocol (participants adhering to the protocol). Missing data will be imputed from previous data entries and regression models may be tested to predict missing outcomes. DISCUSSION: To our knowledge, this is the first study evaluating the feasibility and effects of Baduanjin MBE on CRF using a remote delivery method. These feasibility data will inform a fully powered future trial investigating evidence of effect on CRF and QOL.Trial registration: Australian and New Zealand Clinical Trials Registry (ANZCTR 12623000177651).Ringgold ID: 651498 Chinese Medicine Centre.