Neuroscience

eLife Assessment

Manley and Vaziri introduce an important new method for brain-wide imaging of cellular activity in zebrafish and provide evidence for the applicability of this technique. They use this method to explore the question of how neural variability gives rise to variability in behavior. The analyses used are mostly convincing, although questions regarding spatial and temporal imaging resolution and their effects on the study's interpretations and conclusions suggest only partial support for some of the central results.

eLife Assessment

This manuscript describes methods and software, called SMARTR, to map neuronal networks using markers of neuronal activity. They illustrate their approach using tissue from mice that have undergone behavioral tasks. The reviewers considered the study important to the field and compelling in that the methods and analyses were an advance over current tools.

eLife Assessment

This study represents valuable findings on the asymmetric connectivity pattern of two different types of CA3 pyramidal cell types showing that while athorny cells receive strong inputs from all other cell types, thorny cells receive weaker inputs from athorny neurons. Computational modeling is used to evaluate the impact of this connectivity scheme on the sequential activation of different cell types during sharp wave ripples. The evidence combining experimental and computational modelling approaches convincingly supports the authors' claims regarding the network mechanisms underlying the temporal sequences of neuronal activity during sharp-waves.

eLife Assessment

This important study details changes in the brain functional connectivity in a longitudinal cohort of Gambian children assessed outside a lab setup with functional near-infrared spectroscopy (fNIRS) from age 5 to 24 months, in relation to early physical growth and cognitive flexibility capacities at preschool age. While evidence supporting conclusions on the evolution of brain connectivity are solid, the statistical power was insufficient to perform proper analyses of longitudinal data and link the connectivity trajectories with early adverse conditions such as undernutrition and later cognitive development. This study will be of significant interest to neuroscientists, psychologists and neuroimaging researchers working on infant development in relation to environmental factors.

eLife Assessment

This work defines the response dynamics in forepaw-related cortical circuits of S1 and M1 following stimulation of peripheral mechanoreceptors in the mouse. In this revised version, the authors have addressed the reviewers' prior concerns. The results are convincing and present a valuable comparison to previously published work. This study has implications for understanding the interactions between primary somatosensory and motor cortex, required for active sensing, and will be of interest to scientists seeking to better understand the functions of somatosensory and motor circuits.

eLife Assessment

This valuable work explores how synaptic activity encodes information during memory tasks. All reviewers agree that the work is of very high quality and that the methodological approach is praiseworthy. Although the experimental data support the possibility that phospholipase diacylglycerol signaling and synaptotagmin 7 (Syt7) dynamically regulate the vesicle pool required for presynaptic release, concerns remain that the central finding of paired-pulse depression at very short intervals may be more likely due to Ca²⁺ channel inactivation rather than vesicle pool depletion. Overall, this is a solid study although the results warrant consideration of alternative interpretations.

eLife Assessment

This valuable study provides insights into a key question in comparative neuroanatomy and development. The authors provide evidence of the role for a particular micro-RNA in regulating the development of key transcription factors that control forebrain development. The study rests on clear but incomplete results.

eLife Assessment

This important resource paper presents a library of cell-type-specific genetic driver lines that label wing-related motor and premotor neurons in the ventral nerve cord of the fruit fly, Drosophila. The toolkit is systematically validated with compelling anatomical and behavioral evidence and will provide a resource for future studies of Drosophila flight and courtship.

eLife Assessment

This important work investigates how orientation signals detected in higher brain areas may be transformed into motor responses in behaving animals. The authors characterize two types of descending neurons (DNs) that connect the brain to motor units and are involved in different aspects of turning control. They further show that orientation signals act by preferentially increasing relative stimulation onto left- or right-turn-inducing DNs. These compelling results, together with the independent work that they have inspired, represent significant progress in our understanding of mechanisms of animal navigation.

eLife Assessment

This study investigates the neural basis of causal inference of illness, suggesting that it relies on semantic networks specific to living things in the absence of a generalized representation of causal inference across domains. The main hypothesis is compelling, and is supported by solid methods and data analysis. Overall, the findings make a valuable contribution to understanding the role of domain-specific semantic networks, particularly the precuneus, in implicit causal inference about illness.