scholarly journals Faculty Opinions recommendation of Axodendritic versus axosomatic cochlear efferent termination is determined by afferent type in a hierarchical logic of circuit formation.

2021 ◽  
Author(s):  
Ebenezer Yamoah
Keyword(s):  
Circuit Formation

scholarly journals Implications of Extended Inhibitory Neuron Development

2021 ◽  
Vol 22 (10) ◽  
pp. 5113
Author(s):  
Jae-Yeon Kim ◽  
Mercedes F. Paredes
Keyword(s):  
Neural Circuit ◽  
Inhibitory Neuron ◽  
Postnatal Period ◽  
Specific Pattern ◽  
Inhibitory Neurons ◽  
Gabaergic Interneuron ◽  
Gabaergic Interneurons ◽  
Neuron Development ◽  
Cortical Regions ◽  
Circuit Formation

A prolonged developmental timeline for GABA (γ-aminobutyric acid)-expressing inhibitory neurons (GABAergic interneurons) is an amplified trait in larger, gyrencephalic animals. In several species, the generation, migration, and maturation of interneurons take place over several months, in some cases persisting after birth. The late integration of GABAergic interneurons occurs in a region-specific pattern, especially during the early postnatal period. These changes can contribute to the formation of functional connectivity and plasticity, especially in the cortical regions responsible for higher cognitive tasks. In this review, we discuss GABAergic interneuron development in the late gestational and postnatal forebrain. We propose the protracted development of interneurons at each stage (neurogenesis, neuronal migration, and network integration), as a mechanism for increased complexity and cognitive flexibility in larger, gyrencephalic brains. This developmental feature of interneurons also provides an avenue for environmental influences to shape neural circuit formation.

Optical survey of neural circuit formation in the embryonic chick vagal pathway

2004 ◽  
Vol 19 (5) ◽  
pp. 1217-1225 ◽  
Author(s):  
Katsushige Sato ◽  
Naohisa Miyakawa ◽  
Yoko Momose-Sato
Keyword(s):  
Neural Circuit ◽  
Embryonic Chick ◽  
Vagal Pathway ◽  
Circuit Formation

Role of microRNAs in Semaphorin function and neural circuit formation

2013 ◽  
Vol 24 (3) ◽  
pp. 146-155 ◽  
Author(s):  
Marie-Laure Baudet ◽  
Anaïs Bellon ◽  
Christine E. Holt
Keyword(s):  
Neural Circuit ◽  
Circuit Formation

Perinatal Development of the Medial Nucleus of the Trapezoid Body

2018 ◽  
pp. 244-272
Author(s):  
Shobhana Sivaramakrishnan ◽  
Ashley Brandebura ◽  
Paul Holcomb ◽  
Daniel Heller ◽  
Douglas Kolson ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Neural Circuit ◽  
Neural Cells ◽  
Calyx Of Held ◽  
Medial Nucleus ◽  
Target Neuron ◽  
Circuit Formation ◽  
Key Events ◽  
The Brain ◽  
Trapezoid Body

Bushy cells (BC) of the cochlear nucleus mono-innervate their target neuron, the principal cell of the medial nucleus of the trapezoid body (MNTB), via the calyx of Held (CH) terminal, which is a typically mammalian structure and perhaps the largest nerve terminal in the brain. CH:MNTB innervation has become an attractive model to study neural circuit formation because it forms quickly, passing through stages of competition in mice within 2–4 days. BCs innervate MNTB neurons by E17, but CHs do not begin to grow for another five days (P3). Progress has been made to identify molecular factors for axon guidance, CH growth, and physiological maturation of synaptic partners, but important details remain to be discovered. We summarize key events in CH formation and highlight unresolved issues in molecular and physiological signaling, roles for non-neural cells, and the nature of competition during the first postnatal week.

scholarly journals Neurosteroid Biosynthesis and Action in the Purkinje Cell

2009 ◽  
Vol 2 ◽  
pp. JEN.S2290 ◽  
Author(s):  
Kazuyoshi Tsutsui
Keyword(s):  
Purkinje Cell ◽  
De Novo ◽  
Current Knowledge ◽  
Neuronal Circuit ◽  
Vertebrate Brain ◽  
Neonatal Life ◽  
Cerebellar Neuron ◽  
Brain Data ◽  
Circuit Formation ◽  
Biological Actions

It is now clearly established that steroids can be synthesized de novo by the vertebrate brain. Such steroids are called neurosteroids. To understand neurosteroid action in the brain, data on the regio- and temporal-specific synthesis of neurosteroids are needed. In the middle 1990s, the Purkinje cell, an important cerebellar neuron, was identified as a major site for neurosteroid formation in vertebrates. This discovery has allowed deeper insights into neuronal neurosteroidogenesis and biological actions of neurosteroids have become clear by the studies using the Purkinje cell as an excellent cellular model, which is known to play an important role in memory and learning processes. From the past 10 years of research on mammals, we now know that the Purkinje cell actively synthesizes progesterone and estradiol de novo from cholesterol during neonatal life, when cerebellar neuronal circuit formation occurs. Both progesterone and estradiol promote dendritic growth, spinogenesis, and synaptogenesis via each cognate nuclear receptor in the developing Purkinje cell. Such neurosteroid actions that may be mediated by neurotrophic factors contribute to the formation of cerebellar neuronal circuit during neonatal life. Allopregnanolone, a progesterone metabolite, is also synthesized in the cerebellum and acts on Purkinje cell survival in the neonate. The aim of this review is to summarize the current knowledge regarding the biosynthesis and biological actions of neurosteroids in the Purkinje cell during development.

Developmental shift in bidirectional functions of taurine-sensitive chloride channels during cortical circuit formation in postnatal mouse brain

2004 ◽  
Vol 60 (2) ◽  
pp. 166-175 ◽  
Author(s):  
Mika Yoshida ◽  
Satoshi Fukuda ◽  
Yusuke Tozuka ◽  
Yusei Miyamoto ◽  
Tatsuhiro Hisatsune
Keyword(s):  
Mouse Brain ◽  
Chloride Channels ◽  
Developmental Shift ◽  
Cortical Circuit ◽  
Circuit Formation

scholarly journals Behavioral and Neuroanatomical Consequences of Cell-Type Specific Loss of Dopamine D2 Receptors in the Mouse Cerebral Cortex

2022 ◽  
Vol 15 ◽  
Author(s):  
Gloria S. Lee ◽  
Devon L. Graham ◽  
Brenda L. Noble ◽  
Taylor S. Trammell ◽  
Deirdre M. McCarthy ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Motor Coordination ◽  
Cellular Level ◽  
D2 Receptors ◽  
Dopamine D2 Receptors ◽  
Inhibitory Neurons ◽  
Specific Loss ◽  
Dopamine D2 ◽  
And Behavior ◽  
Circuit Formation

Developmental dysregulation of dopamine D2 receptors (D2Rs) alters neuronal migration, differentiation, and behavior and contributes to the psychopathology of neurological and psychiatric disorders. The current study is aimed at identifying how cell-specific loss of D2Rs in the cerebral cortex may impact neurobehavioral and cellular development, in order to better understand the roles of this receptor in cortical circuit formation and brain disorders. We deleted D2R from developing cortical GABAergic interneurons (Nkx2.1-Cre) or from developing telencephalic glutamatergic neurons (Emx1-Cre). Conditional knockouts (cKO) from both lines, Drd2fl/fl, Nkx2.1-Cre+ (referred to as GABA-D2R-cKO mice) or Drd2fl/fl, Emx1-Cre+ (referred to as Glu-D2R-cKO mice), exhibited no differences in simple tests of anxiety-related or depression-related behaviors, or spatial or nonspatial working memory. Both GABA-D2R-cKO and Glu-D2R-cKO mice also had normal basal locomotor activity, but GABA-D2R-cKO mice expressed blunted locomotor responses to the psychotomimetic drug MK-801. GABA-D2R-cKO mice exhibited improved motor coordination on a rotarod whereas Glu-D2R-cKO mice were normal. GABA-D2R-cKO mice also exhibited spatial learning deficits without changes in reversal learning on a Barnes maze. At the cellular level, we observed an increase in PV+ cells in the frontal cortex of GABA-D2R-cKO mice and no noticeable changes in Glu-D2R-cKO mice. These data point toward unique and distinct roles for D2Rs within excitatory and inhibitory neurons in the regulation of behavior and interneuron development, and suggest that location-biased D2R pharmacology may be clinically advantageous to achieve higher efficacy and help avoid unwanted effects.

scholarly journals The Hunchback temporal transcription factor determines motor neuron axon and dendrite targeting in Drosophila

2019 ◽  
Author(s):  
Austin Q. Seroka ◽  
Chris Q. Doe
Keyword(s):  
Transcription Factor ◽  
Motor Neurons ◽  
Neuronal Diversity ◽  
Molecular Identity ◽  
Extrinsic Cues ◽  
Circuit Development ◽  
Temporal Identity ◽  
Morphological Differences ◽  
And Behavior ◽  
Circuit Formation

AbstractThe generation of neuronal diversity is essential for circuit formation and behavior. Morphological differences in sequentially born neurons could be due to intrinsic molecular identity specified by temporal transcription factors (henceforth called intrinsic temporal identity) or due to changing extrinsic cues. Here we use the Drosophila NB7-1 lineage to address this question. NB7-1 sequentially generates the U1-U5 motor neurons; each has a distinct intrinsic temporal identity due to inheritance of a different temporal transcription factor at time of birth. Here we show that the U1-U5 neurons project axons sequentially, followed by sequential dendrite extension. We misexpress the earliest temporal transcription factor, Hunchback, to create “ectopic” U1 neurons with an early intrinsic temporal identity but later birth-order. These ectopic U1 neurons have axon muscle targeting and dendrite neuropil targeting consistent with U1 intrinsic temporal identity, rather than their time of birth or differentiation. We conclude that intrinsic temporal identity plays a major role in establishing both motor axon muscle targeting and dendritic arbor targeting, which are required for proper motor circuit development.

scholarly journals Efferent feedback enforces bilateral coupling of spontaneous activity in the developing auditory system

2020 ◽  
Author(s):  
Yixiang Wang ◽  
Maya Sanghvi ◽  
Alexandra Gribizis ◽  
Yueyi Zhang ◽  
Lei Song ◽  
...  
Keyword(s):  
Spontaneous Activity ◽  
Auditory System ◽  
Activity Patterns ◽  
Descending Pathways ◽  
Efferent System ◽  
Cholinergic Pathway ◽  
The Central Nervous System ◽  
Necessary And Sufficient ◽  
Circuit Formation

SummaryIn the developing auditory system, spontaneous activity generated in the cochleae propagates into the central nervous system to promote circuit formation before hearing onset. Effects of the evolving peripheral firing pattern on spontaneous activity in the central auditory system are not well understood. Here, we describe the wide-spread bilateral coupling of spontaneous activity that coincides with the period of transient efferent modulation of inner hair cells from the medial olivochlear (MOC) system. Knocking out the α9/α10 nicotinic acetylcholine receptor, a requisite part of the efferent cholinergic pathway, abolishes these bilateral correlations. Pharmacological and chemogenetic experiments confirm that the MOC system is necessary and sufficient to produce the bilateral coupling. Moreover, auditory sensitivity at hearing onset is reduced in the absence of pre-hearing efferent modulation. Together, our results demonstrate how ascending and descending pathways collectively shape spontaneous activity patterns in the auditory system and reveal the essential role of the MOC efferent system in linking otherwise independent streams of bilateral spontaneous activity during the prehearing period.

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