Building the Human Brain: Molecular Logic of Neural Circuit Development and Evolution

The organ of Corti, the sensory epithelium of the mammalian auditory system, uses afferent and efferent synapses for encoding auditory signals and top-down modulation of cochlear function. During development, the final precisely ordered sensorineural circuit is established following excessive formation of afferent and efferent synapses and subsequent refinement. Here, we review the development of innervation of the mouse organ of Corti and its regulation.

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Challenges in Modeling Human Neural Circuit Formation via Brain Organoid Technology

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2020.607399 ◽

2020 ◽

Vol 14 ◽

Author(s):

Takeshi K. Matsui ◽

Yuichiro Tsuru ◽

Ken-ichiro Kuwako

Keyword(s):

Human Brain ◽

Brain Development ◽

Neural Circuit ◽

Disease Modeling ◽

Three Dimensional ◽

Neural Lineage ◽

Human Brain Development ◽

Brain Organoid ◽

Circuit Formation

Human brain organoids are three-dimensional self-organizing tissues induced from pluripotent cells that recapitulate some aspects of early development and some of the early structure of the human brain in vitro. Brain organoids consist of neural lineage cells, such as neural stem/precursor cells, neurons, astrocytes and oligodendrocytes. Additionally, brain organoids contain fluid-filled ventricle-like structures surrounded by a ventricular/subventricular (VZ/SVZ) zone-like layer of neural stem cells (NSCs). These NSCs give rise to neurons, which form multiple outer layers. Since these structures resemble some aspects of structural arrangements in the developing human brain, organoid technology has attracted great interest in the research fields of human brain development and disease modeling. Developmental brain disorders have been intensely studied through the use of human brain organoids. Relatively early steps in human brain development, such as differentiation and migration, have also been studied. However, research on neural circuit formation with brain organoids has just recently began. In this review, we summarize the current challenges in studying neural circuit formation with organoids and discuss future perspectives.

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Neurotrophin, p75, and Trk Signaling Module in the Developing Nervous System of the Marine AnnelidPlatynereis dumerilii

BioMed Research International ◽

10.1155/2016/2456062 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

Antonella Lauri ◽

Paola Bertucci ◽

Detlev Arendt

Keyword(s):

Nervous System ◽

Neuronal Development ◽

Neural Circuit ◽

Circuit Development ◽

Circuit Formation ◽

Neurotrophic Signaling ◽

High Degree ◽

Developing Nervous System

In vertebrates, neurotrophic signaling plays an important role in neuronal development, neural circuit formation, and neuronal plasticity, but its evolutionary origin remains obscure. We found and validated nucleotide sequences encoding putative neurotrophic ligands (neurotrophin, NT) and receptors (Trk and p75) in two annelids,Platynereis dumerilii(Errantia) andCapitella teleta(Sedentaria, for which some sequences were found recently by Wilson, 2009). Predicted protein sequences and structures ofPlatynereisneurotrophic molecules reveal a high degree of conservation with the vertebrate counterparts; some amino acids signatures present in the annelid Trk sequences are absent in the basal chordate amphioxus, reflecting secondary loss in the cephalochordate lineage. In addition, expression analysis of NT, Trk, and p75 duringPlatynereisdevelopment by whole-mount mRNAin situhybridization supports a role of these molecules in nervous system and circuit development. These annelid data corroborate the hypothesis that the neurotrophic signaling and its involvement in shaping neural networks predate the protostome-deuterostome split and were present in bilaterian ancestors.

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