Effects of Cisplatin on the Chick Embryo — A Model for the Analysis of Prenatal Toxicity
Sam Kacew in Drug Toxicity and Metabolism in Pediatrics, 1990
Several basic mechanisms govern the development of the nervous system.27,28 Cell proliferation is, of course, the main mechanism of growth. Mitotic figures can be seen most frequently located in the inner layer of the neural tube (germinal or ependymal layer). At certain sites (cerebral and cerebellar cortices), proliferating cells migrate to the periphery. At all places and times, a certain proportion of the cells resulting from the proliferative process undergoes differentiation into the neuronal or the neuroglial cell lines. In this way, despite the fact that fully differentiated and functional neurons are already present at the early embryonic stages, immature cells in different stages of the differentiation process can be found not only during the embryonic period, but also during most or all of the fetal period. While programmed cell death is a basic mechanism in normal development of the nervous system,28 nonprogrammed, excessive cell death is a frequent teratogenic mechanism. The effects are similar to those produced by inhibition of the mitotic rate as both result in a decreased growth rate. Thus, factors capable of inhibiting mitosis and/or killing immature cells are generally capable of inducing malformations of the disraphiae and obstructive hydrocephalus when acting during the embryonic period, yet are also capable of affecting the development of the brain when acting during the fetal period. Antineoplastic drugs are a good example of teratogens capable of this action.
Developmental Social Neuroscience and the Autism Spectrum of Disorders
Christopher J. Nicholls in Neurodevelopmental Disorders in Children and Adolescents, 2018
The most rapidly growing diagnosis in developmental neuroscience is that of the autism spectrum disorders (ASD). Individuals with autistic-like features and behaviors have existed throughout history and certainly before the term “autism” was formally adopted. In the late 1700s, a 12-year-old child who had grown up in the woods of the south of France, apparently having been without human contact for many years, was found and described as having an absence of speech, peculiar food preferences, and numerous scars on his body. It appeared that he had lived in the wilds for most of his life and was quite content to have done so. Initial efforts to civilize the boy, who became known as Victor, ultimately resulted in his being adopted by a young medical student, John Marc Gaspard Itard. Itard believed that two features separate humans from animals: the capacity to use language and the capacity for empathy (Itard, 1802). Itard attempted to teach Victor to use language and to communicate human emotions; however, he was minimally successful. Ultimately, Victor’s story became dramatized in François Truffaut’s 1970 film L’Enfant Sauvage (The Wild Child).
Caenorhabditis elegans in Computational Research
Theodore B. Achacoso, William S. Yamamoto in AY's Neuroanatomy of C. elegans for Computation, 2022
“…we must move on to other problems of biology which are new, mysterious and exciting…the fields which we should now enter are development and the nervous system,” reads Sydney Brenner’s draft paper, after a long series of conversations with Francis Crick in late 1962. Thus, in a letter dated June 5, 1963 addressed to his chief, Max Perutz, head of the Medical Research Council’s Laboratory of Molecular Biology in Cambridge, England, he wrote “…I would like to tame a small metazoan organism to study development directly.” It was not until 1965, however, that Brenner chose the free-living nematode Caenorhabditis elegans over Caenorhabditis briggsiae which he originally proposed in 1963 to be a model animal for a concerted genetic, ultrastructural, and behavioral investigation of development and function in a simple nervous system.
Attention-Deficit/Hyperactivity Disorder Symptoms, Gastrointestinal Symptoms, Sleep Problems, Challenging Behavior, Adaptive Behavior, and Quality of Life in Children and Adolescents with Autism Spectrum Disorder
Published in Developmental Neurorehabilitation, 2022
Geraldine Leader, Emma Dooley, Sally Whelan, Shawn P. Gilroy, June L. Chen, Autumn Farren Barton, Rory Coyne, Arlene Mannion
Autism Spectrum Disorder (ASD) is characterized by deficits in social interaction and communication as well as restrictive and repetitive patterns of behavior.1,2 In addition to the primary symptoms of ASD, individuals with this disorder often present with a range of related medical and behavioral challenges.3 Recent estimates suggest that over 70% of children diagnosed with ASD will meet the criteria for at least one other comorbid disorder.4 These co-occurring disorders can include sleep problems,5 gastrointestinal (GI) symptoms,6 toileting problems,7 epilepsy,8 behavior problems,9,10 mood disorders,11 fears and phobias,12 anxiety disorders,13 and Attention-Deficit/Hyperactivity Disorder (AD/HD).14 Among co-occurring challenges, individuals with ASD very often present with a range of inattentive and hyperactive behavior.15 Individuals with ASD often present with other neurodevelopmental disorders. A neurodevelopmental disorder is a lifelong condition that affects the development of the nervous system, which can result in atypical brain function and can impact psychological function.16
Exploring Cannabis and Alcohol Co-Use in Adolescents: A Narrative Review of the Evidence
Published in Journal of Dual Diagnosis, 2020
Hollis C. Karoly, J. Megan Ross, Jarrod M. Ellingson, Sarah W. Feldstein Ewing
Importantly, one path toward disaggregating the causal stream of adolescent cannabis use and its intersection with other substance use is through large-scale longitudinal studies, including The National Consortium on Alcohol and Neurodevelopment in Adolescence (N-CANDA), the Imagen Consortium, and the Adolescent Brain Cognitive Development (ABCD) project (Brown et al., 2015; Jernigan, Brown, & ABCD Consortium Coordinators, 2018; Whelan et al., 2012). These studies have large sample sizes and the ABCD study explicitly incorporates a twin design to better assess the nature and progression of substance use onset and its intersection with genetic, familial, peer, and other environmental factors. These projects are promising in terms of truly advancing the field of developmental neuroscience from one that has been largely cross-sectional (Feldstein Ewing et al., 2014) and complicated by small sample sizes to one that can empirically interrogate data over time to answer causal questions (Bjork, 2018).
Neuroethics in the Shadow of a Pandemic
Published in AJOB Neuroscience, 2020
Adina L. Roskies, Ashley Walton
There is significant work in social and developmental neuroscience regarding the effects of loss of control. The phenomenon of learned helplessness has been studied in rats and extended to people (Maier and Seligman 2016); it is more severe in cases of loss of control (Yao et al. 2019). Those who have gotten sick have often reported experiencing severe anxiety; many of those who are vulnerable or who have loved ones sick or at risk have as well. Loss of control, and the feelings of anxiety it provokes, lead to an upsurge in stress hormones (Maier and Seligman 2016). The extended nature of this crisis has led to protracted periods of stress for many, and chronic stress has been shown to have a constellation of negative effects, including neural changes, depression and suicidal ideation, obesity, and immune suppression (McEwen 2017).
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