scholarly journals It Is Not Just in the Genes

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1815
Author(s):  
Martina Manns
Keyword(s):  
Nervous System ◽  
Functional Organization ◽  
Hemispheric Specialization ◽  
Animal Research ◽  
Fine Tuning ◽  
Cellular Mechanisms ◽  
Plastic Potential ◽  
Functional Lateralization ◽  
Level Model ◽  
Developmental Phases

Asymmetries in the functional and structural organization of the nervous system are widespread in the animal kingdom and especially characterize the human brain. Although there is little doubt that asymmetries arise through genetic and nongenetic factors, an overarching model to explain the development of functional lateralization patterns is still lacking. Current genetic psychology collects data on genes relevant to brain lateralizations, while animal research provides information on the cellular mechanisms mediating the effects of not only genetic but also environmental factors. This review combines data from human and animal research (especially on birds) and outlines a multi-level model for asymmetry formation. The relative impact of genetic and nongenetic factors varies between different developmental phases and neuronal structures. The basic lateralized organization of a brain is already established through genetically controlled embryonic events. During ongoing development, hemispheric specialization increases for specific functions and subsystems interact to shape the final functional organization of a brain. In particular, these developmental steps are influenced by environmental experiences, which regulate the fine-tuning of neural networks via processes that are referred to as ontogenetic plasticity. The plastic potential of the nervous system could be decisive for the evolutionary success of lateralized brains.

scholarly journals Incorporation of 5-Bromo-2′-deoxyuridine into DNA and Proliferative Behavior of Cerebellar Neuroblasts: All That Glitters Is Not Gold

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1453
Author(s):  
Joaquín Martí-Clúa
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Nervous System Development ◽  
Current Data ◽  
Cellular Mechanisms ◽  
Dividing Cells ◽  
The Central Nervous System ◽  
Repeated Doses ◽  
Pyrimidine Analog

The synthetic halogenated pyrimidine analog, 5-bromo-2′-deoxyuridine (BrdU), is a marker of DNA synthesis. This exogenous nucleoside has generated important insights into the cellular mechanisms of the central nervous system development in a variety of animals including insects, birds, and mammals. Despite this, the detrimental effects of the incorporation of BrdU into DNA on proliferation and viability of different types of cells has been frequently neglected. This review will summarize and present the effects of a pulse of BrdU, at doses ranging from 25 to 300 µg/g, or repeated injections. The latter, following the method of the progressively delayed labeling comprehensive procedure. The prenatal and perinatal development of the cerebellum are studied. These current data have implications for the interpretation of the results obtained by this marker as an index of the generation, migration, and settled pattern of neurons in the developing central nervous system. Caution should be exercised when interpreting the results obtained using BrdU. This is particularly important when high or repeated doses of this agent are injected. I hope that this review sheds light on the effects of this toxic maker. It may be used as a reference for toxicologists and neurobiologists given the broad use of 5-bromo-2′-deoxyuridine to label dividing cells.

Lineage-dependent spatial and functional organization of the mammalian enteric nervous system

Science ◽  
2017 ◽  
Vol 356 (6339) ◽  
pp. 722-726 ◽  
Author(s):  
Reena Lasrado ◽  
Werend Boesmans ◽  
Jens Kleinjung ◽  
Carmen Pin ◽  
Donald Bell ◽  
...  
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Functional Organization

scholarly journals Cephalopod Retinal Development Shows Vertebrate-like Mechanisms of Neurogenesis

2021 ◽  
Author(s):  
Francesca Napoli ◽  
Christina M Daly ◽  
Stephanie Neal ◽  
Kyle J McCulloch ◽  
Alexandra Zaloga ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nervous System ◽  
Progenitor Cells ◽  
Cellular Proliferation ◽  
Imaging Techniques ◽  
Nuclear Migration ◽  
Live Imaging ◽  
Cellular Mechanisms ◽  
High Resolution Data ◽  
Interkinetic Nuclear Migration

Neurogenesis, the regulation of cellular proliferation and differentiation in the developing nervous system, is the process that underlies the diversity of size and cell type found in animal nervous systems. Our understanding of how this process has evolved is limited because of the lack of high resolution data and live-imaging methods across species. The retina is a classic model for the study of neurogenesis in vertebrates and live-imaging of the retina has shown that during development, progenitor cells are organized in a pseudostratified neuroepithelium and nuclei migrate in coordination with the cell cycle along the apicobasal axis of the cell, a process called interkinetic nuclear migration. Eventually cells delaminate and differentiate within the boundaries of the epithelium. This process has been considered unique to vertebrates and thought to be important in maintaining organization during the development of a complex nervous system. Coleoid cephalopods, including squid, cuttlefish and octopus, have the largest nervous system of any invertebrate and convergently-evolved camera-type eyes, making them a compelling comparative system to vertebrates. Here we have pioneered live-imaging techniques to show that the squid, Doryteuthis pealeii, displays cellular mechanisms during cephalopod retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo interkinetic nuclear migration until they exit the cell cycle, we identify retinal organization corresponding to progenitor, post-mitotic and differentiated cells, and we find that Notch signaling regulates this process. With cephalopods and vertebrates having diverged 550 million years ago, these results suggest that mechanisms thought to be unique to vertebrates may be common to highly proliferative neurogenic primordia contributing to a large nervous system.

scholarly journals Simultaneous high-speed imaging and optogenetic inhibition in the intact mouse brain

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Serena Bovetti ◽  
Claudio Moretti ◽  
Stefano Zucca ◽  
Marco Dal Maschio ◽  
Paolo Bonifazi ◽  
...  
Keyword(s):  
Mouse Brain ◽  
High Speed ◽  
Pyramidal Neurons ◽  
Functional Organization ◽  
Single Photon ◽  
Electrophysiological Recording ◽  
Mammalian Brain ◽  
Cellular Mechanisms ◽  
High Speed Imaging ◽  
Intact Mouse

Abstract Genetically encoded calcium indicators and optogenetic actuators can report and manipulate the activity of specific neuronal populations. However, applying imaging and optogenetics simultaneously has been difficult to establish in the mammalian brain, even though combining the techniques would provide a powerful approach to reveal the functional organization of neural circuits. Here, we developed a technique based on patterned two-photon illumination to allow fast scanless imaging of GCaMP6 signals in the intact mouse brain at the same time as single-photon optogenetic inhibition with Archaerhodopsin. Using combined imaging and electrophysiological recording, we demonstrate that single and short bursts of action potentials in pyramidal neurons can be detected in the scanless modality at acquisition frequencies up to 1 kHz. Moreover, we demonstrate that our system strongly reduces the artifacts in the fluorescence detection that are induced by single-photon optogenetic illumination. Finally, we validated our technique investigating the role of parvalbumin-positive (PV) interneurons in the control of spontaneous cortical dynamics. Monitoring the activity of cellular populations on a precise spatiotemporal scale while manipulating neuronal activity with optogenetics provides a powerful tool to causally elucidate the cellular mechanisms underlying circuit function in the intact mammalian brain.

scholarly journals Functional Aspects of Hypothalamic Asymmetry

2020 ◽  
Vol 10 (6) ◽  
pp. 389
Author(s):  
David Sandor Kiss ◽  
Istvan Toth ◽  
Gergely Jocsak ◽  
Zoltan Barany ◽  
Tibor Bartha ◽  
...  
Keyword(s):  
Hemispheric Specialization ◽  
Functional Asymmetry ◽  
Vast Number ◽  
Brain Functions ◽  
Functional Aspects ◽  
Functional Lateralization ◽  
High Level ◽  
Brain Processing ◽  
Higher Brain Functions ◽  
The Brain

Anatomically, the brain is a symmetric structure. However, growing evidence suggests that certain higher brain functions are regulated by only one of the otherwise duplicated (and symmetric) brain halves. Hemispheric specialization correlates with phylogeny supporting intellectual evolution by providing an ergonomic way of brain processing. The more complex the task, the higher are the benefits of the functional lateralization (all higher functions show some degree of lateralized task sharing). Functional asymmetry has been broadly studied in several brain areas with mirrored halves, such as the telencephalon, hippocampus, etc. Despite its paired structure, the hypothalamus has been generally considered as a functionally unpaired unit, nonetheless the regulation of a vast number of strongly interrelated homeostatic processes are attributed to this relatively small brain region. In this review, we collected all available knowledge supporting the hypothesis that a functional lateralization of the hypothalamus exists. We collected and discussed findings from previous studies that have demonstrated lateralized hypothalamic control of the reproductive functions and energy expenditure. Also, sporadic data claims the existence of a partial functional asymmetry in the regulation of the circadian rhythm, body temperature and circulatory functions. This hitherto neglected data highlights the likely high-level ergonomics provided by such functional asymmetry.

Proprioception From a Spinocerebellar Perspective

2001 ◽  
Vol 81 (2) ◽  
pp. 539-568 ◽  
Author(s):  
G. Bosco ◽  
R. E. Poppele
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Functional Organization ◽  
Body Position ◽  
Historical Context ◽  
Sensory Information ◽  
Functional Relationships ◽  
Central Neurons ◽  
Global Representation ◽  
Limb Kinematics

This review explores how proprioceptive sensory information is organized at spinal cord levels as it relates to a sense of body position and movement. The topic is considered in an historical context and develops a different framework that may be more in tune with current views of sensorimotor processing in other central nervous system structures. The dorsal spinocerebellar tract (DSCT) system is considered in detail as a model system that may be considered as an end point for the processing of proprioceptive sensory information in the spinal cord. An analysis of this system examines sensory processing at the lowest levels of synaptic connectivity with central neurons in the nervous system. The analysis leads to a framework for proprioception that involves a highly flexible network organization based in some way on whole limb kinematics. The functional organization underlying this framework originates with the biomechanical linkages in the limb that establish functional relationships among the limb segments. Afferent information from limb receptors is processed further through a distributed neural network in the spinal cord. The result is a global representation of hindlimb parameters rather than a muscle-by-muscle or joint-by-joint representation.

Sign in / Sign up

Export Citation Format

Share Document