A small population of hypothalamic neurons govern fertility: the critical role of VAX1 in GnRH neuron development and fertility maintenance

Population Density or Populations Size. Which Factor Determines Urban Traffic Congestion?

Sustainability ◽

10.3390/su13084280 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4280

Author(s):

Yu Sang Chang ◽

Sung Jun Jo ◽

Yoo-Taek Lee ◽

Yoonji Lee

Keyword(s):

Population Density ◽

Population Size ◽

Traffic Congestion ◽

Critical Role ◽

Small Population ◽

High Density ◽

Urban Traffic ◽

Contradictory Result ◽

Low Density

A large number of articles have documented that as population density of cities increases, car use declines and public transit use rises. These articles had a significant impact of promoting high-density compact urban development to mitigate traffic congestion. Another approach followed by other researchers used the urban scaling model to indicate that traffic congestion increases as population size of cities increases, thus generating a possible contradictory result. Therefore, this study examines the role of both density and population size on traffic congestion in 164 global cities by the use of Stochastic Impacts by Regression on Population, Affluence and Technology model. We divide 164 cities into the two subgroups of 66 low density cities and 98 high density cities for analysis. The findings from the subgroups analysis indicated a clear-cut difference on the critical role of density in low-density cities and the exclusive role of population size in high-density cities. Furthermore, using threshold regression model, 164 cities are divided into the two regions of large and small population cities to determine population scale advantage of traffic congestion. Our findings highlight the importance of including analysis of subgroups based on density and/or population size in future studies of traffic congestion.

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Critical role of TRPC1 in thyroid hormone-dependent dopaminergic neuron development

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research ◽

10.1016/j.bbamcr.2017.07.019 ◽

2017 ◽

Vol 1864 (10) ◽

pp. 1900-1912 ◽

Cited By ~ 4

Author(s):

Chunhai Chen ◽

Qinglong Ma ◽

Ping Deng ◽

Jianjing Yang ◽

Lingling Yang ◽

...

Keyword(s):

Thyroid Hormone ◽

Dopaminergic Neuron ◽

Critical Role ◽

Neuron Development

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Orexin/Hypocretin and Histamine Cross-Talk on Hypothalamic Neuron Counts in Mice

Frontiers in Neuroscience ◽

10.3389/fnins.2021.660518 ◽

2021 ◽

Vol 15 ◽

Author(s):

Chiara Berteotti ◽

Viviana Lo Martire ◽

Sara Alvente ◽

Stefano Bastianini ◽

Cristiano Bombardi ◽

...

Keyword(s):

Histidine Decarboxylase ◽

Neuron Development ◽

Wild Type ◽

Hypothalamic Neurons ◽

Neuron Number ◽

Knock Out ◽

Orexin Neuron ◽

Knock Out Mice ◽

Deficient Mice

The loss of hypothalamic neurons that produce wake-promoting orexin (hypocretin) neuropeptides is responsible for narcolepsy type 1 (NT1). While the number of histamine neurons is increased in patients with NT1, results on orexin-deficient mouse models of NT1 are inconsistent. On the other hand, the effect of histamine deficiency on orexin neuron number has never been tested on mammals, even though histamine has been reported to be essential for the development of a functional orexin system in zebrafish. The aim of this study was to test whether histamine neurons are increased in number in orexin-deficient mice and whether orexin neurons are decreased in number in histamine-deficient mice. The hypothalamic neurons expressing L-histidine decarboxylase (HDC), the histamine synthesis enzyme, and those expressing orexin A were counted in four orexin knock-out mice, four histamine-deficient HDC knock-out mice, and four wild-type C57BL/6J mice. The number of HDC-positive neurons was significantly higher in orexin knock-out than in wild-type mice (2,502 ± 77 vs. 1,800 ± 213, respectively, one-tailed t-test, P = 0.011). Conversely, the number of orexin neurons was not significantly lower in HDC knock-out than in wild-type mice (2,306 ± 56 vs. 2,320 ± 120, respectively, one-tailed t-test, P = 0.459). These data support the view that orexin peptide deficiency is sufficient to increase histamine neuron number, supporting the involvement of the histamine waking system in the pathophysiology of NT1. Conversely, these data do not support a significant role of histamine in orexin neuron development in mammals.

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Semaphorin Signaling in GnRH Neurons: From Development to Disease

Neuroendocrinology ◽

10.1159/000495916 ◽

2018 ◽

Vol 109 (3) ◽

pp. 193-199 ◽

Cited By ~ 5

Author(s):

Roberto Oleari ◽

Antonella Lettieri ◽

Alyssa Paganoni ◽

Luca Zanieri ◽

Anna Cariboni

Keyword(s):

Embryonic Development ◽

Mouse Models ◽

Neuronal Development ◽

Large Family ◽

Gonadotropin Releasing Hormone ◽

Final Position ◽

Gnrh Neuron ◽

Neuron Development ◽

Hypothalamic Neurons ◽

Gnrh Neurons

In mammals, fertility critically depends on the pulsatile secretion of gonadotropin-releasing hormone (GnRH) by scattered hypothalamic neurons (GnRH neurons). During development, GnRH neurons originate in the nasal placode and migrate first into the nasal compartment and then through the nasal/forebrain junction, before they reach their final position in the hypothalamus. This neurodevelopmental process, which has been extensively studied in mouse models, is regulated by a plethora of factors that might control GnRH neuron migration or survival as well as the fasciculation/targeting of the olfactory/vomeronasal axons along which the GnRH neurons migrate. Defects in GnRH neuron development or release can lead to isolated GnRH deficiency, with the underlying genetic causes still being partially unknown. Recently, semaphorins and their receptors neuropilins and plexins, a large family of molecules implicated in neuronal development and plasticity, are emerging as key regulators of GnRH neuron biology and deficiency. Specifically, semaphorins have been shown to play different roles in GnRH neuron biology by regulating migration and survival during embryonic development as well as secretion in adulthood.

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The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

Perspectives on Language Learning and Education ◽

10.1044/lle15.2.50 ◽

2008 ◽

Vol 15 (2) ◽

pp. 50-59 ◽

Cited By ~ 1

Author(s):

Amy Philofsky

Keyword(s):

Language Development ◽

Critical Role ◽

Children With Autism ◽

Autism Spectrum ◽

Children With Asd ◽

Prevalence Estimates ◽

Notable Increase ◽

Screening Assessment ◽

Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

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