Neuroscience

eLife Assessment

The analysis of neural morphology across Heliconiini butterfly species revealed brain area-specific changes associated with new foraging behaviours. While the volume of the centre for learning and memory, the mushroom bodies, was known to vary widely across species, these new, valuable results show conservation of the volume of a center for navigation, the central complex, but with specific changes in neuropeptide expression in the noduli and in the numbers of ellipsoid body ring neurons. The presented evidence is convincing for both volumetric conservation in the central complex and fine neuroanatomical differences associated with pollen feeding, delivered by experimental approaches that are applicable to other insect species. This work will be of interest to evolutionary biologists, entomologists, and neuroscientists.

eLife Assessment

This is an important paper that reports in vivo physiological abnormalities in the hippocampus of a rat model of traumatic brain injury (TBI). In this study, authors focused on changes in theta-gamma phase coupling and action potential entrainment to theta, phenomena hypothesized to be critical for cognition. The authors provide convincing evidence of deficits in both features post-TBI and contributes new understanding to how disruptions in oscillatory coordination and spike timing may relate to cognitive impairment.

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. Evidence supporting conclusions on the evolution of brain connectivity is convincing and highlights a different trajectory compared with populations from high-income countries. However, analyses linking connectivity trajectories with early adverse conditions such as undernutrition and later cognitive development are only partially supported due to insufficient longitudinal data and statistical power. This study will be of significant interest to neuroscientists, psychologists and neuroimaging researchers working on infant development in relation to environmental factors.

eLife Assessment

Hoverflies are known for their sexually dimorphic visual systems and exquisite flight behaviors. This valuable study reports how two types of visual descending neurons differ between males and females in their motion- and speed-dependent responses, yet surprisingly, the behavior they control lacks any sexual dimorphism. The results convincingly support these findings, which will be of interest for studies of visuomotor transformations and network-level brain organization.

eLife Assessment

This study presents a valuable theoretical exploration on the electrophysiological mechanisms of ionic currents via gap junctions in hippocampal CA1 pyramidal-cell models, and their potentially unique contribution to local field potentials (LFPs). The biophysical foundations of transmembrane electric dipoles, and the associated argument points, are generally compelling. Experimental constraints on gap junctions and strictly quantitative matching between chemical vs. junctional inputs have been hard to achieve. This computational investigation thus offers a specific way to enhance conceptual understanding and provides interesting testable predictions, which would be of great interest to experimental neurophysiologists who interpret relevant recordings.

eLife Assessment

This study addresses an important question in gustatory neuroscience by developing a machine-learning classifier to identify distinct ingestive orofacial movement subtypes from electromyographic recordings and relating their dynamics to population-level activity in the gustatory cortex. The evidence that transitions in cortical ensemble firing are temporally associated with reorganization of ingestive movement patterns is convincing, though some aspects of the behavioral classification and neural analyses require further validation and clarification. The work provides a technically innovative framework for linking neural state dynamics to the motor expression of taste-guided decisions.

eLife Assessment

This fundamental study provides a major contribution to our understanding of Amyotrophic Lateral Sclerosis (ALS) pathogenesis by utilizing a primate model that overcomes the historical limitations of rodent paradigms. By demonstrating the retrograde and trans-synaptic spread of pathological TDP-43 from the periphery to the spinal cord and motor cortex, the authors propose a new model for the disease spreading. The evidence supporting these findings is compelling, characterized by rigorous post-mortem histological observations. This work will be of profound interest to neuroscientists and translational researchers seeking to decode the mechanisms of systemic disease progression in ALS.

eLife Assessment

This study investigates the role of developmental oligodendrocytes in synchronising spontaneous activity in neuronal circuits and influencing cerebellar-dependent behaviour. The authors use advanced viral targeting techniques to deplete oligodendrocytes in a cell-specific manner, paired with in vivo calcium imaging of Purkinje cells, to establish a relationship between oligodendrocyte-mediated neuronal synchrony and complex brain function. The authors present compelling evidence of oligodendrocyte-regulated neuronal synchrony. Overall, this manuscript holds promise as an important contribution to neurodevelopment research.

eLife Assessment

This important study introduces an experimental approach for studying Drosophila oviposition rhythms and identifies the subset of circadian clock neurons that mediate the circadian control of oviposition. The authors resolve an inherently noisy rhythm to provide convincing evidence by using statistical averaging techniques, which help reduce this noise but at the cost of variation across individual rhythms. This paper will be of interest to anyone interested in insect ovarian physiology, circadian biology, and reproductive fitness.

eLife Assessment

This study presents valuable computational findings on the neural basis of learning new motor memories and the savings using recurrent neural networks. The evidence supporting the claims of the authors is solid, but it would benefit from more detailed discussion on the specific conditions under which savings emerges from purely implicit mechanisms. This work will be of interest to computational and experimental neuroscientists working in motor learning.