Origin and evolution of human cognition

A molecular and cellular perspective on human brain evolution and tempo

The evolution of the modern human brain was accompanied by distinct molecular and cellular specializations, which underpin our diverse cognitive abilities but also increase our susceptibility to neurological diseases. These features, some specific to humans and others shared with related species, manifest during different stages of brain development. In this multi-stage process, neural stem cells proliferate to produce a large and diverse progenitor pool, giving rise to excitatory or inhibitory neurons that integrate into circuits during further maturation. This process unfolds over varying time scales across species and has progressively become slower in the human lineage, with differences in tempo correlating with differences in brain size, cell number and diversity, and connectivity. Here we introduce the terms 'bradychrony' and 'tachycrony' to describe slowed and accelerated developmental tempos, respectively. We review how recent technical advances across disciplines, including advanced engineering of in vitro models, functional comparative genetics and high-throughput single-cell profiling, are leading to a deeper understanding of how specializations of the human brain arise during bradychronic neurodevelopment. Emerging insights point to a central role for genetics, gene-regulatory networks, cellular innovations and developmental tempo, which together contribute to the establishment of human specializations during various stages of neurodevelopment and at different points in evolution.

Role and limitation of cell therapy in treating neurological diseases

The central role of the brain in governing systemic functions within human physiology underscores its paramount significance as the focal point of physiological regulation. The brain, a highly sophisticated organ, orchestrates a diverse array of physiological processes encompassing motor control, sensory perception, cognition, emotion, and the regulation of vital functions, such as heartbeat, respiration, and hormonal equilibrium. A notable attribute of neurological diseases manifests as the depletion of neurons and the occurrence of tissue necrosis subsequent to injury. The transplantation of neural stem cells (NSCs) into the brain exhibits the potential for the replacement of lost neurons and the reconstruction of neural circuits. Furthermore, the transplantation of other types of cells in alternative locations can secrete nutritional factors that indirectly contribute to the restoration of nervous system equilibrium and the mitigation of neural inflammation. This review summarized a comprehensive investigation into the role of NSCs, hematopoietic stem cells, mesenchymal stem cells, and support cells like astrocytes and microglia in alleviating neurological deficits after cell infusion. Moreover, a thorough assessment was undertaken to discuss extant constraints in cellular transplantation therapies, concurrently delineating indispensable model-based methodologies, specifically on organoids, which were essential for guiding prospective research initiatives in this specialized field.

A Systematic Review of the Human Accelerated Regions in Schizophrenia and Related Disorders: Where the Evolutionary and Neurodevelopmental Hypotheses Converge

Schizophrenia is a psychiatric disorder that results from genetic and environmental factors interacting and disrupting neurodevelopmental trajectories. Human Accelerated Regions (HARs) are evolutionarily conserved genomic regions that have accumulated human-specific sequence changes. Thus, studies on the impact of HARs in the context of neurodevelopment, as well as with respect to adult brain phenotypes, have increased considerably in the last few years. Through a systematic approach, we aim to offer a comprehensive review of HARs' role in terms of human brain development, configuration, and cognitive abilities, as well as whether HARs modulate the susceptibility to neurodevelopmental psychiatric disorders such as schizophrenia. First, the evidence in this review highlights HARs' molecular functions in the context of the neurodevelopmental regulatory genetic machinery. Second, brain phenotypic analyses indicate that HAR genes' expression spatially correlates with the regions that suffered human-specific cortical expansion, as well as with the regional interactions for synergistic information processing. Lastly, studies based on candidate HAR genes and the global "HARome" variability describe the involvement of these regions in the genetic background of schizophrenia, but also in other neurodevelopmental psychiatric disorders. Overall, the data considered in this review emphasise the crucial role of HARs in human-specific neurodevelopment processes and encourage future research on this evolutionary marker for a better understanding of the genetic basis of schizophrenia and other neurodevelopmental-related psychiatric disorders. Accordingly, HARs emerge as interesting genomic regions that require further study in order to bridge the neurodevelopmental and evolutionary hypotheses in schizophrenia and other related disorders and phenotypes.

White Matter, Behavioral Neurology, and the Influence of Corticocentrism

White matter in the human brain occupies roughly the same volume as gray matter but has received far less attention in behavioral neurology and related disciplines. In particular, the cerebral cortex has long dominated thinking about the organization of brain-behavior relationships. As a result, subcortical structures, including deep gray matter and, most notably, white matter, have been accorded relatively little neuroscientific study compared with the extensive work devoted to the cerebral cortex. The influence of corticocentrism can be explained by several factors, including historical precedent in neurology strongly emphasizing the importance of the cortex, a preponderance of investigative methods that selectively target this structure, and a misinterpretation of comparative neuroanatomic data gathered from normal brains. This paper will describe the background of the corticocentric bias and emphasize that white matter merits its own place within the study of the higher functions. Although corticocentrism continues to exert a powerful impact on behavioral neurology, considerable progress is being made in the study of white matter-a development that promises to expand our knowledge of the normal brain and lead to an improved understanding of how it mediates behavior. In turn, a range of vexing neurologic and psychiatric disorders may become better illuminated by considering pathology within, or dysfunction of, white matter tracts. A complete appreciation of brain-behavior relationships requires an understanding not only of the outermost layer of the cerebral hemispheres, but also of white matter connectivity that links gray matter regions into distributed neural networks that subserve cognition and emotion.

SETMAR, a case of primate co-opted genes: towards new perspectives

BACKGROUND

We carry out a review of the history and biological activities of one domesticated gene in higher primates, SETMAR, by discussing current controversies. Our purpose is to open a new outlook that will serve as a framework for future work about SETMAR, possibly in the field of cognition development.

MAIN BODY

What is newly important about SETMAR can be summarized as follows: (1) the whole protein sequence is under strong purifying pressure; (2) its role is to strengthen existing biological functions rather than to provide new ones; (3) it displays a tissue-specific pattern of expression, at least for the alternative-splicing it undergoes. Studies reported here demonstrate that SETMAR protein(s) may be involved in essential networks regulating replication, transcription and translation. Moreover, during embryogenesis, SETMAR appears to contribute to brain development.

SHORT CONCLUSION

Our review underlines for the first time that SETMAR directly interacts with genes involved in brain functions related to vocalization and vocal learning. These findings pave the way for future works regarding SETMAR and the development of cognitive abilities in higher primates.

Neurobiological Implications of Parent-Child Emotional Availability: A Review

Parental influences are important for a child's behavior, overall adjustment, as well as cognitive/language development. New research is exploring how relationships with parents can influence a child's neurobiological functioning and development. In this systematic review, our first aim is to describe how the caregiving environment influences these aspects of child development. The second and main aim is to review and recommend that the concept (and measurement) of "emotional availability" may provide a new window in this continued exploration. Emotional availability (EA) refers to the capacity of a dyad to share an emotionally healthy relationship. The EA Scales assess this construct using a multi-dimensional framework, with a method to measure the affect and behavior of both the child and adult partner (caregiver). In this review, we first provide an overview of child development research, with regards to stress physiology, neuroendocrine system, genetics and epigenetics, and brain mechanisms. We then summarize the results of specific EA research in these areas, and propose a theoretical model integrating these constructs. Finally, we offer areas for future research in this area.

PolyQ length co-evolution in neural proteins

Intermolecular co-evolution optimizes physiological performance in functionally related proteins, ultimately increasing molecular co-adaptation and evolutionary fitness. Polyglutamine (polyQ) repeats, which are over-represented in nervous system-related proteins, are increasingly recognized as length-dependent regulators of protein function and interactions, and their length variation contributes to intraspecific phenotypic variability and interspecific divergence. However, it is unclear whether polyQ repeat lengths evolve independently in each protein or rather co-evolve across functionally related protein pairs and networks, as in an integrated regulatory system. To address this issue, we investigated here the length evolution and co-evolution of polyQ repeats in clusters of functionally related and physically interacting neural proteins in Primates. We observed function-/disease-related polyQ repeat enrichment and evolutionary hypervariability in specific neural protein clusters, particularly in the neurocognitive and neuropsychiatric domains. Notably, these analyses detected extensive patterns of intermolecular polyQ length co-evolution in pairs and clusters of functionally related, physically interacting proteins. Moreover, they revealed both direct and inverse polyQ length co-variation in protein pairs, together with complex patterns of coordinated repeat variation in entire polyQ protein sets. These findings uncover a whole system of co-evolving polyQ repeats in neural proteins with direct implications for understanding polyQ-dependent phenotypic variability, neurocognitive evolution and neuropsychiatric disease pathogenesis.