Neuroscience

eLife assessment

The present paper describes an important methodological development that combines light (confocal) microscopy with scanning and transmission EM and EM tomography. The method expands the level of structural detail accessible to large-volume EM studies and thus represents an approach to integrate analyses of cellular and sub-cellular structures in biological samples. The study, which provides a compelling proof-of-principle, will be of particular value to cell biologists interested in the in-depth interpretation of high-resolution ultrastructural information from sparsely distributed targets - at multiple scales and in diverse biological structures.

eLife assessment

This valuable study provides new insights into the neural circuits involved in post-mating responses in Drosophila females. It presents convincing evidence that the circuits for mating receptivity and egg-laying are distinct. A more thorough discussion regarding the integration of the new findings into the current understanding of post-mating behavior as well as clarification of some experimental details would further improve the manuscript.

eLife assessment

This fundamental study provides a near-comprehensive anatomical description and annotation of neurons in a male Drosophila ventral nerve cord, based on large-scale circuit reconstruction from electron microscopy. This connectome resource will be of substantial interest to neuroscientists interested in sensorimotor control, neural development, and analysis of brain connectivity. However, although the evidence is extensive and compelling, the presentation of results in this very large manuscript lacks clarity and concision.

eLife assessment

This paper describes an important advance in an in vitro neural culture system to generate mature, functional, diverse, and geometrically consistent cultures, in a 384-well format with defined dimensions and the absence of the necrotic core, which persists for up to 300 days. The well-based format and conserved geometry make it a promising tool for arrayed screening studies. Some of the evidence is incomplete and could benefit from a more direct head-to-head comparison with more standard culture methods and standardization of cell seeding density as well as further data on reproducibility in each well and for each cell line.

eLife assessment

This study presents a useful method for the extraction of behaviour-related activity from neural population recordings based on a specific deep learning architecture, a variational autoencoder. Although the authors performed thorough benchmarking of their method in the context of decoding behavioural variables, the evidence supporting claims about encoding is incomplete as the results may stem, in part, from the properties of the method itself.

eLife assessment

Calcium channels are key regulators of synaptic strength and plasticity. The authors generate new endogenous tags of the Drosophila channel Cac as well as auxiliary subunits to investigate distinct calcium channel functions at the fly NMJ, Is and Ib. They demonstrate functions for voltage-gated calcium channel subunits in promoting synaptic strength, diversity, and plasticity with a series of convincing analyses. The work is important and has broad implications. In addition, the newly developed tools should be quite beneficial for fly biologists.

eLife assessment

This study presents an important finding on the relationship between brain activity related to sustained attention and substance use in adolescence/early adulthood with a large longitudinal dataset. The evidence supporting the claims of the authors is convincing. The work will be of interest to cognitive neuroscientists, psychologists, and clinicians working on substance use or addiction.

eLife assessment

This paper provides potentially useful insight into why memory consolidation may differ between children (5-7 years of age) and adults. The work hints at developmental differences in neural engagement during the retrieval of recent and remote memories. However, there are several major issues with the experimental design and analyses that render the evidence supporting the authors' main claims incomplete.

eLife assessment

The authors show that short bouts of chemical ischemia lead to presynaptic changes in glutamate release and long-term potentiation, whereas longer bouts of chemical ischemia lead to synaptic failure and presumably cell death. This convincing work relies on rigorous electrophysiology/imaging experiments and data analysis. It is important as it provides new mechanistic details on chemical ischemia, which could offer potential insights into ischemic stroke in vivo.

eLife assessment

The authors' innovative use of single-cell sequencing combined with physiological phenotyping of 5 different Parkinsons models in Drosophila provides compelling support for the important conclusion that these different models have a shared convergent effect on olfactory projection neuron (OPN) dysfunction. The effect on OPN occurs early in disease progression, and likely underlies anosmia observed as an early symptom of PD. Additional experiments and analysis are required to support the authors' suggestions that: (a) the defect in these models is specific to cholinergic OPNs; (b) that OPN degeneration is (causally) connected to dopaminergic neuron (DAN) degeneration; and also (c) that observed motor defects are reasonable measure of DAN dysfunction.