Neuroscience

eLife assessment

This manuscript makes a major contribution to the study of early visual representation in primates by showing that intermediate cortical areas V2 and V4, as well as primary cortical area V1 (previously shown), contain orthogonal maps of orientation and spatial frequency, which are recursive across the visual field representation. This is a fundamental principle of functional mapping across the two-dimensional cortical surface that ensures and optimizes the complete representation of all combinations across two coding dimensions.

eLife assessment

This paper deploys elegant genetic tools to understand how synapses are formed in the Drosophila central nervous system. The synaptic connections between two identified neurons in the Drosophila central nervous system are used as a system to document the role of cell ablation and activity in dendrite growth and circuit wiring. In so doing, they identify a brief window of time that appears critical for these wiring and growth decisions.

eLife assessment

This paper is expected to be of interest to systems neuroscientists in the fields of emotion, hippocampal function, and anxiety-related behavior. The authors performed recordings in ventral hippocampus and show that 1) place fields become concentrated near the open areas of a maze, 2) direction-dependent coding decreases in these open areas, and 3) ventral hippocampal population activity in the closed area can be used to predict how mice explore the open area in the immediate future. These valuable findings support a potential role for the ventral hippocampus in the exploration of anxiety-provoking environments, however, the manuscript in its current form is incomplete, with some support for the main findings but also some limitations.

eLife assessment

This is a useful study exploring multi-modality brain age (structural plus resting state MRI) in people in the early stages or at risk of Alzheimer's disease. They found solid evidence that people with cognitive impairment had older-appearing brains and that older-appearing brains were related to Alzheimer's risk factors such as amyloid and tau deposition. They claim to show that the multi-modality brain age model is more accurate than a unimodal structural MRI model, though the evidence for that is incomplete.

eLife assessment

This is an important and fundamental, well-written and easily comprehended quantitative imaging study, analyzing the motion of endo-lysosomal compartments within axons in vivo using simultaneous multiphoton imaging in the mammalian brain. Taken together, this is a significant technical advance with interesting observations that substantively move the field forward.

eLife assessment

Hebart et al., present a new massive multi-model dataset to support the study of visual object representation, including data measured from functional magnetic resonance imaging, magnetoencephalography, and behavioral similarity judgments. The general, condition-rich design, conducted over a thoughtfully curated and sampled set of object concepts will be highly valuable to the cognitive/computational/neuroscience community, yielding data that will be amenable to many empirical questions beyond the field of visual object recognition. The dataset is accompanied by quality control evaluations as well as examples of analyses that the community can re-run and further explore for building new hypotheses that can be tested with such a rich dataset.

eLife assessment

This manuscript is relevant to experimental and theoretical neuroscientists interested in the trade-off between chaos and reliability in the brain, and may also pique the interest of the machine learning community, particularly those seeking to understand the computational capacity of recurrent neural networks. The findings are valuable, with practical and theoretical implications for this subfield. Using a spiking neural network model firmly anchored in experimental data from the turtle brain, the authors examine the reliability and flexibility of spike train sequences and determine the differential roles of strong and weak connections. The results show clearly that strong but sparse connections in a sub-network can produce a highly reliable response to single spikes, with reliability and multiplexing across sub-networks controlled by weak connectivity. The strength of evidence for the claims is convincing, using appropriate and validated methodology in line with current state-of-the-art.

eLife assessment

In this manuscript, the authors address the variable results and data regarding the role of the FAAH variant (C385A at the nucleotide level and P129T at the protein level) in the control of feeding. The authors hypothesize that the variable results might be due to the environmental context, specifically stress related conditions. They designed studies to address the role of glucocorticoids in regulating feeding and metabolism.

eLife assessment

In this study the authors show that neural tuning for object orientation in IT is unaffected by whole-body tilt, suggesting that neurons are encoding objects relative to the gravitational vertical. However, these observations could also be because IT neurons may encode object orientation relative to cues and not due to gravity, or due to dynamic, compensatory torsional eye movements made by the animals. With these concerns adequately addressed, this would be an important study showing that IT neurons may play a role not only in object recognition but more broadly in physical scene understanding.

eLife assessment

This fundamental work reveals a novel direct projection from the lateral entorhinal cortex to the medial entorhinal cortex. Using multiple techniques, the authors provide compelling evidence that fan cells from the lateral entorhinal cortex project to superficial neurons in the medial entorhinal cortex. This newly identified connection may support the combination of spatial inputs with sensory or high-order signals, providing novel insight into potentially how the 'what' (lateral entorhinal cortex) and 'where' (medial entorhinal cortex) features of memory are incorporated.