China
Africa
Explore chapters and articles related to this topic
Pregnancy
Published in Michelle Tollefson, Nancy Eriksen, Neha Pathak, Improving Women's Health Across the Lifespan, 2021
Nancy L. Eriksen, Kristi R. VanWinden, Anne Bingham, John McHugh
High levels of stress can also negatively impact fetal brain development. Fetal magnetic resonance imaging scans show a decrease in hippocampal volume and a decrease in cortical gyrification in the frontal and temporal lobes of the brain in women with psychological distress leading to anxiety.191 In addition, stress can alter fetal brain connectivity between the brainstem and sensorimotor areas.192 Cumulatively, these findings suggest that high stress during pregnancy can result in fetal programming of the brain that goes on to affect their offspring.
Principles of neuromotor development
Published in Mijna Hadders-Algra, Kirsten R. Heineman, The Infant Motor Profile, 2021
Mijna Hadders-Algra, Kirsten R. Heineman
In the third trimester of gestation, the cortex increases in size, and gyrification starts (Kostović and Judas 2010). During this phase, the thickness of the subplate decreases, while the cortical plate increases. This also implies that the human cortex at this time is characterized by the co-existence of two separate but interconnected cortical circuitries: the transient foetal circuitries centred in the subplate and the immature, but progressively developing, permanent circuitry centred in the cortical plate. The double circuitry state ends when the subplate has dissolved. This situation is reached in the primary motor, sensory, and visual cortices around three months post-term, but first around the age of one year in the associative prefrontal cortex (Kostović et al. 2014b).
Neuroimaging in late-onset schizophrenia
Published in Anne M. Hassett, David Ames, Edmond Chiu, Psychosis in the Elderly, 2005
Mark Walterfang, Ramon Mocellin, Dennis Velakoulis, Christos Pantelis
The structural abnormalities reported in LOS have been described in EOS. These include enlarged global ventricular volume, lateral ventricles, and third but not fourth ventricle (Shelton et al, 1986; Shenton et al, 2001; Mark and Ulmer, 2004). In addition, the evidence of global cortical atrophy is similarly weak in EOS (Ward et al, 1996; Shenton et al, 2001), while evidence of abnormalities in the temporal lobe such as the superior temporal gyrus and amygdala are found regularly if not invariably (McCarley et al, 1999; Shenton et al, 2001; Liddle and Pantelis, 2003). However, some neurodevelopmental abnormalities reported with moderate frequency in EOS, such as cavum septum pellucidum, callosal dysgenesis, and abnormal gyrification have not been described in LOS (Almeida, 1999; McCarley et al, 1999). Volume reductions in the hippocampus have been robustly established in EOS (Nelson et al, 1998; Velakoulis et al, 1999), but only two studies in LOS have found conflicting findings (Howard et al, 1995b; Barta et al, 1997). This may be in some way due to the low base rate of neurodevelopmental abnormalities in both schizophrenic and control subject populations in combination with small sample sizes in most LOS studies, in addition to the dearth of studies examining specific medial temporal structures with volumetric methods.
The perversion of language: Jules Baillarger on aphasia, the lateralization of speech, and the Baillarger-Jackson principle
Published in Journal of the History of the Neurosciences, 2021
But how could the cortex, “which is barely one line and a half thick,”11Three-point four mm. (Baillarger 1840, 176). generate enough electricity to perform the operations of the brain? Baillarger proposed that the generation of electrical activity by the cortex is related not to its thickness but to its surface area, which is considerable when the gyral pattern is unfolded (Baillarger 1845). He concluded that, as gyrification reaches its maximum in the human brain, and as man is the most intelligent of creatures, the cortex must be the seat of human intelligence, as well as the generator of animal electricity (Baillarger 1840, 174–76). Such an idea implied that the generation of cortical activity is a self-generating, electro-chemical process independent of any metaphysical intervention.12This was demonstrated by Rafael Lorente de Nó (1902–1990; Lorente de Nó, 1938). Lorente de Nó was a student of Cajal, and his discovery of self-generation cortical circuits led Donald Hebb (1904–1985) to conceive of the engram (Hebb, 1980) In this, Baillarger reflected the strength of the Libre-pensée (Freethought) movement that was sweeping through France at the time, by which rational explanations, freed from myth and theology, were sought to explain natural phenomena (Lalouette 1997).13The Freethought movement was a determining factor in the localization of speech (Lalouette 1997, 27–28, 89; Leblanc, 2020).
Neuroanniversary 2021
Published in Journal of the History of the Neurosciences, 2021
Thomas Willis (1621–1675) established neurology as a distinct discipline and made numerous significant original contributions to many related fields, including anatomy, pathology, cardiology, endocrinology, and gastroenterology. He was a founding member of the Royal Society. His anatomy of the brain and nerves is described in his Cerebri Anatome of 1664, and in this book he coined the term “neurology.” In 1667, Willis published, Pathologicae Cerebri, et Nervosi Generis Specimen [An Essay of the Pathology of the Brain and Nervous Stock), primarily dealing with pathology and neurophysiology of the brain. In it he developed a new theory of the cause of epilepsy and other convulsive diseases, and contributed to the development of psychiatry. In 1672, he published the earliest English work on medical psychology, Two Discourses Concerning the Soul of Brutes, Which Is That of the Vital and Sensitive of Man. Willis was the first to number the cranial nerves in the order in which they are now usually enumerated by anatomists (six of which are still classified in the same way today). He described the corpora striata and optic thalami; the four orbicular eminences, with the bridge, which he first named annular protuberance; and the white mammillary eminences, behind the infundibulum. He described in the cerebellum the arborescent arrangement of the white and gray matter and gave a good account of the internal carotids and the connection with the branches of the basilar artery. He deduced that the ventricles contained cerebrospinal fluid that collected waste products. He regarded the cortex as the substrate of cognition, and he claimed that the gyrification was related to a progressive increase in the complexity of cognition. He coined the term “mellitus” in diabetes mellitus, also called Willis’s disease in the past. He was also first to describe myasthenia gravis, in 1671.
Pathways of atopic disease and neurodevelopmental impairment: assessing the evidence for infant antibiotics
Published in Expert Review of Clinical Immunology, 2022
Elizabeth Volker, Carmen Tessier, Nicole Rodriguez, Jerome Yager, Anita Kozyrskyj
Human brain development continues through our lifespan as a finely-tuned and well-organized sequence of events beginning with the differentiation of embryonic stem cells into neurons (neurogenesis) and glial cells (gliogenesis) [1]. This is followed with the formation of the neural tube, the earliest phase of the entire central nervous system, at 3–4 weeks of gestation. With closure of the neural tube, tremendous cell proliferation and migration follow, resulting in the formation of different ‘modules’ of the brain that ultimately form the cortex and its neural connectivity with other parts of the brain. Brain development is well orchestrated by gene expression, in a spacio-temporal fashion, leading to layering of neurons in the cortex. Over the course of gestation, gyrification (or folding of the cortex) occurs predominantly in the last trimester. Key cells in this process are: i) astrocytes that guide migration of neurons from the deeper to the superficial cortex, ii) oligodendrocytes that myelinate neuronal axons, and iii) microglia, the brain’s resident immune cells which control cell proliferation and differentiation, and modify and prune neuronal synapses [2]. Alongside the migration of cortical neurons and expansion of neural connectivity, an increase in number of astrocytes, oligodendrocytes, and microglial cells contributes to cortical expansion and gyrification. While the degree of cortical folding remains constant after birth, gyrification continues throughout infancy and is primarily affected by microglial pruning of synapses [3]. This complexity of gyrification provides for the advanced cognition, intelligence, emotionality and reasoning, characteristic of the human brain. Its complex nature also renders many critical windows of vulnerability to genetic and environmental factors, such that a malfunctioning cortex (due to microglial dysfunction, for example), is associated with a broad range of cognitive deficits, including attention-deficit disorder (ADHD) and autism spectrum disorder (ASD) [4,5].