Inherited mitochondrial dysfunction triggered by OPA1 mutation impacts the sensory innervation fibre identity, functionality and regenerative potential in the cornea.

Mitochondrial dysfunctions are detrimental to organ metabolism. The cornea, transparent outmost layer of the eye, is prone to environmental aggressions, such as UV light, and therefore dependent on adequate mitochondrial function. While several reports have linked corneal defects to mitochondrial dysfunction, the impact of OPA1 mutation, known to induce such dysfunction, has never been studied in this context.

A systematic review and multivariate meta-analysis of the physical and mental health benefits of touch interventions.

Receiving touch is of critical importance, as many studies have shown that touch promotes mental and physical well-being. We conducted a pre-registered (PROSPERO: CRD42022304281) systematic review and multilevel meta-analysis encompassing 137 studies in the meta-analysis and 75 additional studies in the systematic review (n = 12,966 individuals, search via Google Scholar, PubMed and Web of Science until 1 October 2022) to identify critical factors moderating touch intervention efficacy. Included studies always featured a touch versus no touch control intervention with diverse health outcomes as dependent variables.

Can mirror self-recognition in mice unpack the neural underpinnings of self-awareness?

In this issue of Neuron, Yokose et al. show that mice groom a mark on their forehead when exposed to a mirror. Comparing this behavior with hominids' helps carve self-awareness into its component parts and explore the neural mechanisms of its shared components.

Three Strategies to Induce Neurotrophic Keratitis and Nerve Regeneration in Murine Cornea.

The cornea is a transparent tissue that covers the eye and is crucial for clear vision. It is the most innervated tissue in the body. This innervation provides sensation and trophic function to the eye and contributes to preserving corneal integrity.

Predictability alters information flow during action observation in human electrocorticographic activity.

The action observation network (AON) has been extensively studied using short, isolated motor acts. How activity in the network is altered when these isolated acts are embedded in meaningful sequences of actions remains poorly understood. Here we utilized intracranial electrocorticography to characterize how the exchange of information across key nodes of the AON-the precentral, supramarginal, and visual cortices-is affected by such embedding and the resulting predictability.

Audible pain squeaks can mediate emotional contagion across pre-exposed rats with a potential effect of auto-conditioning.

Footshock self-experience enhances rodents' reactions to the distress of others. Here, we tested one potential mechanism supporting this phenomenon, namely that animals auto-condition to their own pain squeaks during shock pre-exposure. In Experiment 1, shock pre-exposure increased freezing and 22 kHz distress vocalizations while animals listened to the audible pain-squeaks of others.

Sharing Positive Affective States Amongst Rodents.

Group living is thought to benefit from the ability to empathize with others. Much attention has been paid to empathy for the pain of others as an inhibitor of aggression. Empathizing with the positive affect of others has received less attention although it could promote helping by making it vicariously rewarding.

Zebrafish cornea formation and homeostasis reveal a slow maturation process, similarly to terrestrial vertebrates' corneas.

Corneal blindness is the fourth leading cause of blindness worldwide. The superficial position of cornea on the eye makes this tissue prone to environmental aggressions, which can have a strong impact on sight. While most corneal pathology studies utilize terrestrial models, the knowledge on zebrafish cornea is too scarce to comprehend its strategy for the maintenance of a clear sight in aquatic environment.

AAV2/9-mediated gene transfer into murine lacrimal gland leads to a long-term targeted tear film modification.

Corneal blindness is the fourth leading cause of blindness worldwide. Since corneal epithelium is constantly renewed, non-integrative gene transfer cannot be used to treat corneal diseases. In many of these diseases, the tear film is defective.

Hypolacrimia and Alacrimia as Diagnostic Features for Genetic or Congenital Conditions.

As part of the lacrimal apparatus, the lacrimal gland participates in the maintenance of a healthy eye surface by producing the aqueous part of the tear film. Alacrimia and hypolacrimia, which are relatively rare during childhood or young adulthood, have their origin in a number of mechanisms which include agenesia, aplasia, hypoplasia, or incorrect maturation of the gland. Moreover, impaired innervation of the gland and/or the cornea and alterations of protein secretion pathways can lead to a defective tear film.

Zebrafish Corneal Wound Healing: From Abrasion to Wound Closure Imaging Analysis.

As the transparent surface of the eye, the cornea is instrumental for clear sight. Due to its location, this tissue is prone to environmental insults. Indeed, the eye injuries most frequently encountered clinically are those to the cornea.

Unilateral zebrafish corneal injury induces bilateral cell plasticity supporting wound closure.

The cornea, transparent and outermost structure of camera-type eyes, is prone to environmental challenges, but has remarkable wound healing capabilities which enables to preserve vision. The manner in which cell plasticity impacts wound healing remains to be determined. In this study, we report rapid wound closure after zebrafish corneal epithelium abrasion.

Single-trial dynamics of hippocampal spatial representations are modulated by reward value.

Reward value is known to modulate learning speed in spatial memory tasks, but little is known about its influence on the dynamical changes in hippocampal spatial representations. Here, we monitored the trial-to-trial changes in hippocampal place cell activity during the acquisition of place-reward associations with varying reward size. We show a faster reorganization and stabilization of the hippocampal place map when a goal location is associated with a large reward.

Implantation of Neuropixels probes for chronic recording of neuronal activity in freely behaving mice and rats.

How dynamic activity in neural circuits gives rise to behavior is a major area of interest in neuroscience. A key experimental approach for addressing this question involves measuring extracellular neuronal activity in awake, behaving animals. Recently developed Neuropixels probes have provided a step change in recording neural activity in large tissue volumes with high spatiotemporal resolution.

Sox21 Regulates Anapc10 Expression and Determines the Fate of Ectodermal Organ.

The transcription factor Sox21 is expressed in the epithelium of developing teeth. The present study aimed to determine the role of Sox21 in tooth development. We found that disruption of Sox21 caused severe enamel hypoplasia, regional osteoporosis, and ectopic hair formation in the gingiva in Sox21 knockout incisors.

A Dual Reward-Place Association Task to Study the Preferential Retention of Relevant Memories in Rats.

Memories of past events and common knowledge are critical to flexibly adjust one's future behavior based on prior experiences. The formation and the transformation of these memories into a long-lasting form are supported by a dialogue between populations of neurons in the cortex and the hippocampus. Not all experiences are remembered equally well or equally long.

System for recording from multiple flexible polyimide neural probes in freely behaving animals.

Objective: Long-term electrophysiological recordings of neural activity in freely behaving animals are indispensable to advance the understanding of complex brain function. It is a technical challenge to chronically monitor the detailed activity across multiple distributed brain regions in freely behaving animals over a period of months. Here we present a new implant for inserting multiple flexible polyimide probes into freely behaving rats for monitoring the brain activity over a long time period.

Tooth bioengineering from single cell suspensions.

Recent advances in bioengineering and biomaterials, along with knowledge deriving from the fields of developmental biology and stem cell research, have rendered feasible functional replacement of full organs. Here, we describe the methodology for bioengineering a tooth, starting from embryonic epithelial and mesenchymal single cell suspensions. In addition, we describe the subsequent steps of processing this minute structure for use in applications such as histological examination, immunofluorescence and hybridisation.

Ectodysplasin-A signaling is a key integrator in the lacrimal gland-cornea feedback loop.

A lack of ectodysplasin-A (Eda) signaling leads to dry eye symptoms, which have so far only been associated with altered Meibomian glands. Here, we used loss-of-function () mutant mice to unravel the impact of Eda signaling on lacrimal gland formation, maturation and subsequent physiological function. Our study demonstrates that activity is dispensable during lacrimal gland embryonic development.

Post-learning Hippocampal Replay Selectively Reinforces Spatial Memory for Highly Rewarded Locations.

Offline replay of hippocampal neural patterns supports the acquisition of new tasks in novel contexts, but its contribution to consolidation of salient experiences in a familiar context is unknown. Here, we show that in a highly familiar spatial memory task, large rewards selectively enhanced performance for demanding task configurations. The reward-related enhancement was sensitive to ripple-specific disruption, and the proportion of replay events positively correlated with reward size and task demands.

Dental Epithelial Stem Cells Express the Developmental Regulator .

MEIS1 is a key developmental regulator of several organs and participates in stem cell maintenance in different niches. However, despite the murine continuously growing incisor being a well described model for the study of adult stem cells, has not been investigated in a dental context. Here, we uncover that expression in the tooth is confined to the epithelial compartment.

Real-Time Readout of Large-Scale Unsorted Neural Ensemble Place Codes.

Uncovering spatial representations from large-scale ensemble spike activity in specific brain circuits provides valuable feedback in closed-loop experiments. We develop a graphics processing unit (GPU)-powered population-decoding system for ultrafast reconstruction of spatial positions from rodents' unsorted spatiotemporal spiking patterns, during run behavior or sleep. In comparison with an optimized quad-core central processing unit (CPU) implementation, our approach achieves an ∼20- to 50-fold increase in speed in eight tested rat hippocampal, cortical, and thalamic ensemble recordings, with real-time decoding speed (approximately fraction of a millisecond per spike) and scalability up to thousands of channels.

Real-time classification of experience-related ensemble spiking patterns for closed-loop applications.

Communication in neural circuits across the cortex is thought to be mediated by spontaneous temporally organized patterns of population activity lasting ~50 -200 ms. Closed-loop manipulations have the unique power to reveal direct and causal links between such patterns and their contribution to cognition. Current brain-computer interfaces, however, are not designed to interpret multi-neuronal spiking patterns at the millisecond timescale.