Trends in Neurosciences最新文献

Several recent studies, enabled by advances in neuroimaging methods and large-scale datasets, have identified areas in human ventral visual cortex that respond more strongly to food images than to images of many other categories, adding to our knowledge about the broad network of regions that are responsive to food. This finding raises important questions about the evolutionary and developmental origins of a possible food-selective neural population, as well as larger questions about the origins of category-selective neural populations more generally. Here, we propose a framework for how visual properties of food (particularly color) and nonvisual signals associated with multimodal reward processing, social cognition, and physical interactions with food may, in combination, contribute to the emergence of food selectivity. We discuss recent research that sheds light on each of these factors, alongside a broader account of category selectivity that incorporates both visual feature statistics and behavioral relevance.

Parkinson's disease (PD) is a significant source of morbidity, especially with an aging population. Gait problems, particularly freezing of gait (FOG), remain a persistent issue, causing falls and reduced quality of life without consistent responses to therapies. PD and related symptoms have classically been attributed to dopamine deficiency secondary to substantia nigra degeneration from Lewy body (LB) and Lewy neurite (LN) infiltration. However, Lewy-related pathology is present in other areas of the brainstem and spinal cord that control gait function, yet these other circuits have not been routinely considered in the design of current therapeutic options. In this review, we summarize changes in brainstem and spinal cord circuits in individuals affected by PD and the implications for understanding of gait dysfunction in PD.

Despite accounting for only ~0.001% of all neurons in the human brain, midbrain dopaminergic neurons control numerous behaviors and are associated with many neuropsychiatric disorders that affect our physical and mental health. Dopaminergic neurons form various anatomically and functionally segregated pathways. Having such defined dopaminergic pathways is key to controlling varied sets of brain functions; therefore, segregated dopaminergic pathways must be properly and uniquely formed during development. How are these segregated pathways established? The three key developmental stages that dopaminergic neurons go through are cell migration, axon guidance, and synapse formation. In each stage, dopaminergic neurons and their processes receive unique molecular cues to guide the formation of specific dopaminergic pathways. Here, we outline the molecular mechanisms underlying the establishment of segregated dopaminergic pathways during each developmental stage in the mouse brain, focusing on the formation of the three major dopaminergic pathways: the nigrostriatal, mesolimbic, and mesocortical pathways. We propose that multiple stage-specific molecular gradients cooperate to establish functionally segregated dopaminergic circuits.

Memory consolidation requires rapid energy supply to neurons. In a recent study, Francés et al. revealed the signal by which a neuron commands glia to limit fatty acid synthesis in favor of metabolite export during memory formation in Drosophila melanogaster. This mechanism coordinates just-in-time glial energy delivery in response to dynamic neuronal needs.

The precise organization of the complex set of synaptic proteins at the nanometer scale is crucial for synaptic transmission. At the heart of this nanoscale architecture lies the nanocolumn. This aligns presynaptic neurotransmitter release with a high local density of postsynaptic receptor channels, thereby optimizing synaptic strength. Although synapses exhibit diverse protein compositions and nanoscale organizations, the role of structural diversity in the notable differences observed in synaptic physiology remains poorly understood. In this review we examine the current literature on the molecular mechanisms underlying the formation and maintenance of nanocolumns, as well as their role in modulating various aspects of synaptic transmission. We also discuss how the reorganization of nanocolumns contributes to functional dynamics in both synaptic plasticity and pathology.

Chemotherapy treatment can significantly increase the survival of patients with cancer, but it also causes collateral damage in the body that can lead to treatment dose reductions and can reduce patient quality of life. One understudied side effect of chemotherapy is circadian disruption, which is associated with lasting biological and behavioral toxicities. Mechanisms of how chemotherapy alters circadian rhythms remain largely unknown, although leveraging rodent models may provide insights into causes and consequences of this disruption. Here, we review physiological, molecular, and behavioral evidence of central and peripheral circadian disruption in various rodent models of chemotherapy and discuss possible mechanisms driving these circadian disruptions. Overall, restoring circadian rhythms following treatment-induced disruptions may be a novel target by which to improve the health and quality of life of survivors.

The evolution of vertebrates from protochordate ancestors marked the beginning of the gradual transition to predatory lifestyles. Enabled by the acquisition of multipotent neural crest and cranial placode cell populations, vertebrates developed an elaborate peripheral nervous system, equipped with paired sense organs, which aided in adaptive behaviors and ultimately, successful colonization of diverse environmental niches. Underpinning the enduring success of vertebrates is the highly adaptable nature of the peripheral nervous system, which is enabled by the exceptional malleability of the neural crest and placode developmental programs. Here, we explore the embryonic origins of the vertebrate senses from the neural crest and cranial placodes and discuss the evolutionary trajectory of the senses in the context of adaptation to novel environments.

Despite extensive functional mapping studies using rodent functional magnetic resonance imaging (fMRI), interpreting the fMRI signals in relation to their neuronal origins remains challenging due to the hemodynamic nature of the response. Ultra high-resolution rodent fMRI, beyond merely enhancing spatial specificity, has revealed vessel-specific hemodynamic responses, highlighting the distinct contributions of intracortical arterioles and venules to fMRI signals. This 'single-vessel' fMRI approach shifts the paradigm of rodent fMRI, enabling its integration with other neuroimaging modalities to investigate neuro-glio-vascular (NGV) signaling underlying a variety of brain dynamics. Here, we review the emerging trend of combining multimodal fMRI with opto/chemogenetic neuromodulation and genetically encoded biosensors for cellular and circuit-specific recording, offering unprecedented opportunities for cross-scale brain dynamic mapping in rodent models.

How do you know you have heard right? Metacognition, the ability to assess and monitor one's own cognitive state, is key to understanding human communication in complex environments. However, the foundational role of metacognition in hearing and communication is only beginning to be explored, and the neuroscience behind it is an emerging field: how does confidence express in neural dynamics of the listening brain? What is known about auditory metaperceptual alterations as a hallmark phenomenon in psychosis, dementia, or hearing loss? Building on Bayesian ideas of auditory perception and auditory neuroscience, 'meta-listening' offers a framework for more comprehensive research into how metacognition in humans and non-humans shapes the listening brain.

Somatostatin-expressing (SST) neurons are a major class of electrophysiologically and morphologically distinct inhibitory cells in the mammalian neocortex. Transcriptomic data suggest that this class can be divided into multiple subtypes that are correlated with morpho-electric properties. At the same time, availability of transgenic tools to identify and record from SST neurons in awake, behaving mice has stimulated insights about their response properties and computational function. Neocortical SST neurons are regulated by sleep and arousal, attention, and novelty detection, and show marked response plasticity during learning. Recent studies suggest that subtype-specific analysis of SST neurons may be critical for understanding their complex roles in cortical function. In this review, we discuss and synthesize recent advances in understanding the diversity, circuit integration, and functional properties of this important group of GABAergic neurons.