Neuroscience

eLife Assessment

Bonnifet et al. present data on the expression and interacting partners of the transposable element L1 in the mammalian brain. The work includes important findings addressing the potential role of L1 in aging and neurodegenerative disease. The reviewers conclude that several aspects of the study are well done. However, the experimental evidence presented supporting the L1 increase with aging is not fully conclusive and this finding remains incomplete in its current form.

eLife Assessment

This fundamental study describes patterns of anatomical connectivity between the cortex and the thalamus using magnetic resonance imaging data in humans and non-human primates. The measures are related to numerous other modalities to develop a robust understanding of the organisation of the system. The authors provide convincing evidence that there is a difference between sensory and association cortices in terms of their connectivity with the thalamus, which may have downstream effects on brain function. This work will be of interest to neuroscientists interested in the organization and dynamics of cortico-thalamic circuits.

eLife Assessment

This paper shows that it is possible to optogenetically activate single retinal ganglion cells in vivo in monkeys. This is an important step towards towards causal tests of the role of specific ganglion cell types in visual perception. The paper presents convincing evidence for the promise of the approach but further work will be needed to full explore its limitations and specificity.

eLife Assessment

Using a combination of connectomics, optogenetics, behavioral analysis, and modeling, this study provides important findings on the role of two populations of inhibitory neurons in the generation of leg grooming movements in Drosophila. The data as presented provide incomplete evidence that the identified neuronal populations contribute to the alternation of flexion and extension by inhibiting specific sets of motor neurons while disinhibiting their counterparts. While the manuscript provides comprehensive details about the 13A/B neuronal populations involved in grooming control, updates on statistics, and explicit mentioning of experimental/modeling caveats would strengthen the study. The work will interest neuroscientists, and particularly those working on motor control.

eLife Assessment

This is a valuable and rigorous study that addresses the question of what determines the spatial organization of endocytic zones at synapses. The authors use compelling approaches, in both Drosophila and rodent model systems, to define the role of activity and active zone structure on the organization of the peri-active zone. While the findings are primarily negative, they are carefully executed and contribute to the field by refining existing models of presynaptic organization.

eLife Assessment

This manuscript provides valuable information on the neurodynamics of emotional processing while participants were watching movie clips. The methods and results were solid in deciphering the temporal-spatial dynamics of emotional processing. This work will be of interest to affective neuroscientists.

eLife Assessment

Karimian et al. present a valuable new model to explain how gamma-band synchrony (30-80 Hz) can support human visual feature binding by selectively grouping image elements, countering recent criticisms that the stimulus dependence of gamma oscillations limits their functional role. Grounded in the theory of weakly coupled oscillators and informed by primate electrophysiology, the model captures behavioural patterns observed in human psychophysics, offering support for the potential role of synchrony-based mechanisms, but incomplete evidence for a specific role of gamma oscillations. This work could be strengthened by more direct evidence for the proposed mechanism, and expanding beyond figure-only model inputs with limited ecological validity.

eLife Assessment

The authors design and implement an elegant strategy to delete genomic sequences encoding the dopamine receptor dop1R2 from specific subsets of mushroom body neurons (ab, a'b' and gamma) and show that while none of these manipulations affect short term appetitive or aversive memory, loss of dop1R2 from ab or a'b' block the ability of flies to display measurable forms of longer forms of memory. These findings are important in confirming and extending prior observations, and well supported by convincing evidence that build on precise techniques for genetic perturbation.

eLife Assessment

In this valuable study, Nold et al. examined exercise-induced pain modulation in a pharmacological within-subject fMRI study using the opioid-antagonist naloxone and different levels of aerobic exercise intensity and pain. This investigation provides solid evidence to show that the intensity of exercise does not seem to impact the hypoalgesic effect. Moreover, exploratory analysis identified that fitness level and sex may potentially play a role in exercise-induced hypoalgesia, and that further confirmatory studies are required in order to verify these findings.

eLife Assessment

The study is a timely and important contribution to our knowledge of the circuit mechanisms of fear analgesia. The novel cue-induced analgesia paradigm allowed a compelling identification of a brainstem circuit element, i.e., somatostatin-expressing neurons within the ventrolateral periaqueductal grey that project to the rostroventral medulla, in mediating fear analgesia. The vlPAG is a known region of pain modulation, and this study adds key insight to the circuit involved in fear-associated analgesia. This work will be of interest to systems and behavioral neuroscientists, especially those interested in emotional behavior, pain, and/or brainstem function.