Current Biology : CB

Neurons have differential and fluctuating energy needs across distinct cellular compartments, shaped by brain electrochemical activity associated with cognition. In vitro studies show that mitochondria transport from soma to axons is key to maintaining neuronal energy homeostasis. Nevertheless, whether the spatial distribution of neuronal mitochondria is dynamically adjusted in vivo in an experience-dependent manner remains unknown. In Drosophila, associative long-term memory (LTM) formation is initiated by an early and persistent upregulation of mitochondrial pyruvate flux in the axonal compartment of neurons in the mushroom body (MB)...

The ability of fungi to establish mycorrhizal associations with plants and enhance the acquisition of mineral nutrients stands out as a key feature of terrestrial life. Evidence indicates that arbuscular mycorrhizal (AM) association is a trait present in the common ancestor of land plants,1 , 2 , 3 , 4 suggesting that AM symbiosis was an important adaptation for plants in terrestrial environments.5 The activation of nuclear calcium signaling in roots is essential for AM within flowering plants.6 Given that the earliest land plants lacked roots, whether nuclear calcium signals are required for AM in non-flowering plants is unknown...

Substantial progress has been made in understanding the genetic architecture of phenotypes involved in a variety of evolutionary processes. Behavioral genetics remains, however, among the least understood. We explore the genetic architecture of spatial cognitive abilities in a wild passerine bird, the mountain chickadee (Poecile gambeli). Mountain chickadees cache thousands of seeds in the fall and require specialized spatial memory to recover these caches throughout the winter. We previously showed that variation in spatial cognition has a direct effect on fitness and has a genetic basis...

The insular cortex, or insula, is a large brain region involved in the detection of thirst and the regulation of water intake. However, our understanding of the topographical, circuit, and molecular mechanisms for controlling water intake within the insula remains parcellated. We found that type-1 cannabinoid (CB1 ) receptors in the insular cortex cells participate in the regulation of water intake and deconstructed the circuit mechanisms of this control. Topographically, we revealed that the activity of excitatory neurons in both the anterior insula (aIC) and posterior insula (pIC) increases in response to water intake, yet only the specific removal of CB1 receptors in the pIC decreases water intake...

Honey bees play a major role in crop pollination but have experienced declining health throughout most of the globe. Despite decades of research on key honey bee stressors (e.g., parasitic Varroa destructor mites and viruses), researchers cannot fully explain or predict colony mortality, potentially because it is caused by exposure to multiple interacting stressors in the field. Understanding which honey bee stressors co-occur and have the potential to interact is therefore of profound importance. Here, we used the emerging field of systems theory to characterize the stressor networks found in honey bee colonies after they were placed in fields containing economically valuable crops across Canada...

Migration can be an energetically costly behavior with strong fitness consequences in terms of mortality and reproduction.1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 Migrants should select migratory routes to minimize their costs, but both costs and benefits may change with experience.12 , 13 , 14 This raises the question of whether experience changes how individuals select their migratory routes. Here, we investigate the effect of age on route selection criteria in a collectively migrating soaring bird, the white stork (Ciconia ciconia)...

Learning to discriminate overlapping gustatory stimuli that predict distinct outcomes-a feat known as discrimination learning-can mean the difference between ingesting a poison or a nutritive meal. Despite the obvious importance of this process, very little is known about the neural basis of taste discrimination learning. In other sensory modalities, this form of learning can be mediated by either the sharpening of sensory representations or the enhanced ability of "decision-making" circuits to interpret sensory information...

The primary visual cortex (V1) and the superior colliculus (SC) both occupy stations early in the processing of visual information. They have long been thought to perform distinct functions, with the V1 supporting the perception of visual features and the SC regulating orienting to visual inputs. However, growing evidence suggests that the SC supports the perception of many of the same visual features traditionally associated with the V1. To distinguish V1 and SC contributions to visual processing, it is critical to determine whether both areas causally contribute to the detection of specific visual stimuli...

Environmental enrichment (EE) improves memory, particularly the ability to discriminate similar past experiences.1 , 2 , 3 , 4 , 5 , 6 The hippocampus supports this ability via pattern separation, the encoding of similar events using dissimilar memory representations.7 This is carried out in the dentate gyrus (DG) and CA3 subfields.8 , 9 , 10 , 11 , 12 Upregulation of adult neurogenesis in the DG improves memory through enhanced pattern separation.1 , 2 , 3 , 4 , 5 , 6 , 11 , 13 , 14 , 15 , 16 Adult-born granule cells (abGCs) in DG are suggested to contribute to pattern separation by driving inhibition in regions such as CA3,13 , 14 , 15 , 16 , 17 , 18 leading to sparser, nonoverlapping representations of similar events (although a role for abGCs in driving excitation in the hippocampus has also been reported16 )...

Self-incompatibility (SI) has evolved independently multiple times and prevents self-fertilization in hermaphrodite angiosperms. Several groups of Oleaceae such as jasmines exhibit distylous flowers, with two compatibility groups each associated with a specific floral morph.1 Other Oleaceae species in the olive tribe have two compatibility groups without associated morphological variation.2 , 3 , 4 , 5 The genetic basis of both homomorphic and dimorphic SI systems in Oleaceae is unknown. By comparing genomic sequences of three olive subspecies (Olea europaea) belonging to the two compatibility groups, we first locate the genetic determinants of SI within a 700-kb hemizygous region present only in one compatibility group...

In flowering plants, outcrossing is commonly ensured by self-incompatibility (SI) systems. These can be homomorphic (typically with many different allelic specificities) or can accompany flower heteromorphism (mostly with just two specificities and corresponding floral types). The SI system of the Oleaceae family is unusual, with the long-term maintenance of only two specificities but often without flower morphology differences. To elucidate the genomic architecture and molecular basis of this SI system, we obtained chromosome-scale genome assemblies of Phillyrea angustifolia individuals and related them to a genetic map...

It is unclear how animals with radial symmetry control locomotion without a brain. Using a combination of experiments, mathematical modeling, and robotics, we tested the extent to which this control emerges in sea stars (Protoreaster nodosus) from the local control of their hundreds of feet and their mechanical interactions with the body. We discovered that these animals compensate for an experimental increase in their submerged weight by recruiting more feet that synchronize in the power stroke of the locomotor cycle during their bouncing gait...

Low genomic diversity is generally indicative of small population size and is considered detrimental by decreasing long-term adaptability.1 , 2 , 3 , 4 , 5 , 6 Moreover, small population size may promote gene flow with congeners and outbreeding depression.7 , 8 , 9 , 10 , 11 , 12 , 13 Here, we examine the connection between habitat availability, effective population size (Ne ), and extinction by generating a 40× nuclear genome from the extinct blue antelope (Hippotragus leucophaeus). Historically endemic to the relatively small Cape Floristic Region in southernmost Africa,14 , 15 populations were thought to have expanded and contracted across glacial-interglacial cycles, tracking suitable habitat...

Prefrontal (PFC) and hippocampal (HPC) sequences of neuronal firing modulated by theta rhythms could represent upcoming choices during spatial memory-guided decision-making. How the PFC-HPC network dynamically coordinates theta sequences to predict specific goal locations and how it is interrupted in memory impairments induced by amyloid beta (Aβ) remain unclear. Here, we detected theta sequences of firing activities of PFC neurons and HPC place cells during goal-directed spatial memory tasks. We found that PFC ensembles exhibited predictive representation of the specific goal location since the starting phase of memory retrieval, earlier than the hippocampus...

Aberrant cognitive network activity and cognitive deficits are established features of chronic pain. However, the nature of cognitive network alterations associated with chronic pain and their underlying mechanisms require elucidation. Here, we report that the claustrum, a subcortical nucleus implicated in cognitive network modulation, is activated by acute painful stimulation and pain-predictive cues in healthy participants. Moreover, we discover pathological activity of the claustrum and a region near the posterior inferior frontal sulcus of the right dorsolateral prefrontal cortex (piDLPFC) in migraine patients during acute pain and cognitive task performance...

The anterior cingulate cortex (ACC) is critical for the perception and unpleasantness of pain.1 , 2 , 3 , 4 , 5 , 6 It receives nociceptive information from regions such as the thalamus and amygdala and projects to several cortical and subcortical regions of the pain neuromatrix.7 , 8 ACC hyperexcitability is one of many functional changes associated with chronic pain, and experimental activation of ACC pyramidal cells produces hypersensitivity to innocuous stimuli (i.e., allodynia).9 , 10 , 11 , 12 , 13 , 14 A less-well-studied projection to the ACC arises from a small forebrain region, the claustrum...

Researchers investigating the evolution of human aggression look to our closest living relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes), as valuable sources of comparative data.1 , 2 Males in the two species exhibit contrasting patterns: male chimpanzees sexually coerce females3 , 4 , 5 , 6 , 7 , 8 and sometimes kill conspecifics,9 , 10 , 11 , 12 whereas male bonobos exhibit less sexual coercion13 , 14 and no reported killing.13 Among the various attempts to explain these species differences, the self-domestication hypothesis proposes negative fitness consequences of male aggression in bonobos...

Different signaling mechanisms concur to ensure robust tissue patterning and cell fate instruction during animal development. Most of these mechanisms rely on signaling proteins that are produced, transported, and detected. The spatiotemporal dynamics of signaling molecules are largely unknown, yet they determine signal activity's spatial range and time frame. Here, we use the Caenorhabditis elegans embryo to study how Wnt ligands, an evolutionarily conserved family of signaling proteins, dynamically organize to establish cell polarity in a developing tissue...

Prophages, viral sequences integrated into bacterial genomes, can be beneficial and costly. Despite the risk of prophage activation and subsequent bacterial death, active prophages are present in most bacterial genomes. However, our understanding of the selective forces that maintain prophages in bacterial populations is limited. Combining experimental evolution with stochastic modeling, we show that prophage maintenance and loss are primarily determined by environmental conditions that alter the net fitness effect of a prophage on its bacterial host...

In face-to-face interactions with infants, human adults exhibit a species-specific communicative signal. Adults present a distinctive "social ensemble": they use infant-directed speech (parentese), respond contingently to infants' actions and vocalizations, and react positively through mutual eye-gaze and smiling. Studies suggest that this social ensemble is essential for initial language learning. Our hypothesis is that the social ensemble attracts attentional systems to speech and that sensorimotor systems prepare infants to respond vocally, both of which advance language learning...