Neuroscience

eLife assessment

In this manuscript, Gonzalez et al investigated the dynamics of dopamine signals in the lateral shell of the nucleus accumbens (LNAc) in response to different types of carefully defined visual stimuli. Contrary to reigning theories of dopamine signaling, the authors presented convincing evidence that LNAcc dopamine transients tracked visual sensory transitions rather than any immediately apparent motivational variable. These important findings based on compelling evidence point to a potentially new role for dopamine signaling in the ventral striatum.

eLife assessment

This important study should be of interest to vision scientists and those seeking to model naturalistic image processing for humans in simulated or real navigational [walking] situations. The experiments aim to provide information about the statistics of "retinal" motion patterns generated by human participants physically walking a straight path in real terrains that differ in "smoothness". State-of-the-art eye, head, and body tracking allowed simultaneous assessment of eye movements, head movements, and gait, with convincing evidence for an asymmetrical gradient of flow speeds during walking, tied predominantly to vertical gaze angle, together with a radial motion direction distribution tied most critically on horizontal gaze angle. While not a major weakness per se, additional details on analytical methods used and estimations of variance across observers would strengthen these results and clarify the basis of the global claims made about visual motion information across the visual field in walking humans.

eLife assessment

This work provides a promising first pass at providing an integrative model for how decisions arise from neural circuits. The approach is novel but lacks a more rigorous vetting against alternative model formulations to be able to determine its true significance. More stringent evaluations of the model in the context of existing work, as well as a clearer description of the goals and implementation of the approach, would help to address these concerns.

eLife assessment

The authors revisit fundamentals of synaptic transmission using a combination of advanced optical methods capable of visualizing calcium influx and neurotransmitter release at single release sites. By doing so, the authors present evidence for silencing of neurotransmitter release at single release sites as a function of external calcium. The data have relevance to a wide range of phenomena including neural plasticity and inhibitory modulation of synaptic communication.

eLife assessment

This important landmark paper identifies three distinct stellate ganglion nerve cell subtypes stratifiable in terms of their neuropeptide Y expression correlating these with gene expression and electrophysiological properties. Their innovative use of viral tracing techniques compellingly established their conclusions. This major contribution to cardiac sympathetic excitation is relevant to a wide scientific and clinical audience.

eLife assessment

This important work demonstrates a significant asymmetry between the connectivity statistics of the left and right hemispheres of the Drosophila larva brain. The evidence supporting the conclusions is compelling and represents a first step toward the development of statistical tests for comparing pairs of connectomes more generally. This work will therefore be of interest to the broad neuroscience community.

eLife assessment

Gordon-Fennell et al. present a low-cost, open-source platform for measuring action elicitation and consummatory behavior in head-fixed animals. The findings are important because they allow animals to perform a truly voluntary action whilst their head is held still, and the evidence supporting them is both comprehensive and compelling (in some cases even exceptional). The results have the potential to have a broad impact in the field as many labs start to move towards measuring head-fixed behavior effectively, although this is said with the caveat that such behavior will never be an ideal replication of naturalistic behavior.

eLife assessment

This valuable paper examines the effect of deiodinase polymorphism on thyroid hormone signaling in the brain by employing a transgenic animal model and then switching to studying T3 axonal transport using microfluid devices. Although methodologically extensive this paper has several claims that are not convincingly supported by the current experiments and furthermore some disjoint is observed between the two halves of the study. The therapeutic implications of understanding T3 signaling in the brain makes it a potentially important manuscript.

eLife assessment

This is an important study that asks why odors smell similar even though their chemical structures appear quite different. The authors use machine-learning to make a compelling case to map the odor-relatedness of compounds to their place in metabolic pathways and propose that this is a general feature of odor perception across the animal kingdom. The conclusions could be strengthened by considering published physiological data.

eLife assessment

This study uses behavioral monitoring and cutting-edge calcium imaging approaches to track the activity of cholinergic and noradrenergic axons in cortex of head-fixed mice, and correlate activity with behavioral state. While the evidence that behaviorally related signals are broadly broadcasted to the dorsal cortex is clear from the data, the conclusion that there is also heterogeneity across axons and areas is of less certain significance and might be undermined by methodological artifacts.