Dentate granule cells encode auditory decisions after reinforcement learning in rats

Auditory-cued goal-oriented behaviors requires the participation of cortical and subcortical brain areas, but how neural circuits associate sensory-based decisions with goal locations through learning remains poorly understood. The hippocampus is critical for spatial coding, suggesting its possible involvement in transforming sensory inputs to the goal-oriented decisions. Here, we developed an auditory discrimination task in which rats learned to navigate to goal locations based on the frequencies of auditory stimuli. Using in vivo calcium imaging in freely behaving rats over the course of learning, we found that dentate granule cells became more active, spatially tuned, and responsive to task-related variables as learning progressed. Furthermore, only after task learning, the activity of dentate granule cell ensembles represented the navigation path and predicts auditory decisions as early as when rats began to approach the goals. Finally, chemogenetic silencing of dentate gyrus suppressed task learning. Our results demonstrate that dentate granule cells gain task-relevant firing pattern through reinforcement learning and could be a potential link of sensory decisions to spatial navigation.

[Systematic review of methodological quality and reporting quality in gastric cancer screening guidelines]

Objective: To systematically evaluate the quality of gastric cancer screening guidelines/recommendations, and provide a reference for the update of gastric cancer screening guidelines/recommendations in China. Methods: "guidelines/consensus/specifications/standards" , "stomach/gastric tumors" , "screening/diagnosis" , "guideline/recommendation" , "gastric cancer/gastric tumor," "early detection of cancer/screening" were searched as keywords in PubMed, Embase, Web of knowledge, China Knowledge Network, Wanfang, China Biomedical Literature Database, and Cochrane Library, as well as the US Preventive Services Working Group, the American Cancer Society, the International Agency for Research on Cancer, the Australia Cancer Council and the International Guide Collaboration Network at the end of July 2018. The inclusion criteria were independent guidelines/recommendation documents for gastric cancer screening. The exclusion criteria were guideline abstracts, interpretation and evaluation literature, duplicate publications, updated original guidelines, and clinical treatment or practice guidelines for gastric cancer. The language was limited to Chinese and English. The European Guide to Research and Evaluation Tools (AGREE Ⅱ) and Practice Guideline Reporting Standard (RIGHT) for Gastric Cancer Screening Guidelines/Recommendations were used to compare and evaluate the quality and reporting standard of gastric cancer screening guidelines/recommendations. Results: A total of five guides/recommendations were included. The results of the AGREE Ⅱ quality evaluation showed that the overall quality of five guides/recommendations was different, including one recommended for "A", one for "B", and three for "C". Each guide/recommendation scored higher in the scope and purpose, clarity, and scores were more significant in the areas of rigor and independence. In the participants, the application field scores were generally low. The RIGHT evaluation results showed that the quality of five guides/recommendations should be improved. The six items with poor report quality were background, evidence, recommendations, review and quality assurance, funding and conflict of interest statement and management, and other aspects. Conclusion: The quality of the included gastric cancer screening guidelines/recommendations is generally low, and the standardization should be strengthened.

Cortical ensemble activity discriminates auditory attentional states

Selective attention modulates sensory cortical activity. It remains unclear how auditory cortical activity represents stimuli that differ behaviorally. We designed a cross-modality task in which mice made decisions to obtain rewards based on attended visual or auditory stimuli. We recorded auditory cortical activity in behaving mice attending to, ignoring, or passively hearing auditory stimuli. Engaging in the task bidirectionally modulates neuronal responses to the auditory stimuli in both the attended and ignored conditions compared to passive hearing. Neuronal ensemble activity in response to stimuli under attended, ignored and passive conditions are readily distinguishable. Furthermore, ensemble activity under attended and ignored conditions are in closer states compared to passive condition, and they share a component of attentional modulation which drives them to the same direction in the population activity space. Our findings suggest that the ignored condition is very different from the passive condition, and the auditory cortical sensory processing under ignored, attended and passive conditions are modulated differently.

[Systematic review of the methodology quality and reporting quality in colorectal cancer screening guidelines]

Objective: To systematically review the quality and reporting quality of colorectal cancer screening guidelines, and to provide reference for the update of colorectal cancer screening guidelines and colorectal cancer screening in China. Methods: "Colorectal cancer", "colorectal tumor", "screening", "screening", "guide", "consensus", "Colorectal cancer", "Colorectal neoplasms", "Screening", "Early Detection of Cancer", "Guideline" and "recommendation" were used as search keywords. The literature retrieval for all the Chinese and English guidelines published before April 2018 was conducted by using PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Data, China Biology Medicine disc (CBMdisc), Cochrane Library, Guideline International Network, China Guidelines Clearinghouse (CGC) and the official website of the US Preventive Services Task Force (USPSTF), the American Cancer Society (ACS), International Agency for Research on Cancer (IARC), Australia Cancer Council (ACC) and Association of Coloproctology of Great Britain & Ireland (ACPGBI). The inclusion criteria were independent guidance documents for colorectal cancer screening. The language is limited to Chinese and English. The exclusion criteria were literature on interpretation, evaluation, introduction, etc., as well as the translated version of the guide and old guides. The quality and reporting norms of colorectal cancer screening guidelines were compared and evaluated using the European Guideline Research and Assessment Tool (AGREE Ⅱ) and the Practice Guideline Reporting Standard (RIGHT). Results: A total of 15 guides were included. The results of the AGREE Ⅱ quality evaluation showed that the overall quality of 15 guides was high. Among them, there were 9 guides with an overall score of 50 or more, 10 with a recommendation level of "A", and 2 with a rating of "B". There were 3 guides for "C"; each guide scores higher in scope and purpose, and clarity, and scores vary greatly in the areas of participants, rigor, applicability, and independence. The results of the RIGHT evaluation showed that 15 guides were insufficient in six areas except for background information, evidence, recommendations, reviews and quality assurance, funding and conflict of interest statements and management, and other aspects. Conclusion: The overall quality of included guidelines for colorectal cancer screening is high, but the normative nature needs to be strengthened.