Design-Based Stereology in Brain Aging Research
David R. Riddle in Brain Aging, 2007
The most challenging issue is to identify reliably cortical areas in the human brain. Cortical areas are delineated by the pial surface, the cortex-white matter transition, and their borders with neighboring areas. Defining the pial surface and the cortex-white matter border is usually not a problem on histological sections. However, the crucial step in identifying a cortical area is the localization of its borders with neighboring areas. In this respect, a cortical area is defined as a cortical tissue volume characterized by a homogeneous microstructural organization (i.e., by its cytoarchitecture). Thus, a regional border must be established at locations where the cytoarchitecture of the cortex changes considerably. All classical anatomical maps of the primate cerebral cortex (including human) are based on this axiom, but they suffer from several limitations. In particular, these maps do not reflect intersubject variability in the size of cortical areas and the location of their borders [86], although several cytoarchitectural studies have indicated the existence of a considerable degree of intersubject variability [87–90]. In addition, these “classical” cortical maps are usually two-dimensional, highly schematic drawings, which do not provide the information necessary for correlations with recently developed functional imaging techniques in the living human brain. Finally, there are striking differences between the maps of different authors in terms of the number, localization, extent, and contour of cortical areas (see [91]).
ENTRIES A–Z
Philip Winn in Dictionary of Biological Psychology, 2003
The visual cortex is located in the occipital lobes (see OCCIPITAL LOBE). Because the visual pathway is partially crossed, the left visual cortex receives from the left side of each retina and represents the right visual field. The term visual cortex refers strictly to area V1 (see AREAS V1-V5) in PRIMATES. Also known as PRIMARY VISUAL CORTEX, or STRIATE CORTEX or area 17 (see BRODMANN'S AREAS), it contains a complete map of its half of the visual field. The higher-order visual areas are located in areas 18 and 19 and other regions. The term VISUAL CORTEX is often used to refer to the collection of areas including both the striate cortex and the EXTRASTRIATE CORTEX which have been heavily implicated in the processing of visual information (such as and are concerned with motion, depth, colour and orientation of edges). There are at least 25 such areas expanding over all four lobes of the CEREBRAL CORTEX, with several hundred connections between them and may account for over 50% of the primate cortical area.
Brain Motor Centers and Pathways
Nassir H. Sabah in Neuromuscular Fundamentals, 2020
Movements are planned or programmed in the motor association areas of the cerebral cortex with the involvement of other brain regions, depending on the type of movement concerned. Planning of a movement generally involves: (i) knowledge of the surroundings and of the position of the body with respect to these surroundings, based on sensory inputs, which may include visual, auditory, and proprioceptive inputs; and (ii) a decision on what is judged to be the appropriate action, based on factors such as past experience (memory), motivation, and emotional state. Hence, planning of movement generally involves other, non-motor, cortical, and brain regions, which necessitates connections between these regions and motor association area, particularly parietal regions (for sensory inputs) and frontal regions (for higher mental functions). Anatomically, the motor areas are located between these two regions.
Effects of 1800 MHz RF-EMF exposure on DNA damage and cellular functions in primary cultured neurogenic cells
Published in International Journal of Radiation Biology, 2018
Liling Su, Aziguli Yimaer, Zhengping Xu, Guangdi Chen
Astrocytes and microglia, two major types of glial cells, involved in the regulation of the immune response to pathological processes as well as in the development of brain cancer. The cerebral cortex is the largest region of the mammalian brain and plays a key role in memory, attention, perception and cognition. Cortical neurons are crucially involved in associative brain functions and have been proven to be a valuable cell model to study neuronal function and developmental neurotoxicity. Therefore, we included primary cultured astrocytes, microglia and cortical neurons in our study to evaluate the genotoxicity of 1800 MHz RF-EMF by detection of γH2AX foci formation, an early marker of DNA double-strand breaks (DSB) (Rogakou et al. 1998). Because of the diverse functions of different neurogenic cells, we also investigated the immunological roles of astrocytes and microglia and neuronal development in cortical neurons upon RF-EMF exposure.
Approaches for CNS delivery of drugs – nose to brain targeting of antiretroviral agents as a potential attempt for complete elimination of major reservoir site of HIV to aid AIDS treatment
Published in Expert Opinion on Drug Delivery, 2019
Shweta Gupta, Rajesh Kesarla, Abdelwahab Omri
The brain is the largest portion of the CNS and is the main structure referred to when considering the nervous system. The brain is the major functional unit of the CNS and a highly protected organ from the periphery by two major barriers, the BBB and the BCSFB. In a typical human, the cerebral cortex (the largest part) is estimated to contain 15–33 billion neurons [38], each connected by synapses to several thousand neurons. Microglia is a type of glial cell located throughout the brain and spinal cord [39]. Microglia comprises 10–15% of all cells found within the brain. As the resident macrophage cells, they act as the first and main form of active immune defense in CNS [40]. Microglia (and other glia including astrocytes) are distributed in large non-overlapping regions throughout the CNS [41].
Reduced astrocyte density underlying brain volume reduction in activity-based anorexia rats
Published in The World Journal of Biological Psychiatry, 2018
Linda Frintrop, Johanna Liesbrock, Lisa Paulukat, Sonja Johann, Martien J. Kas, Rene Tolba, Nicole Heussen, Joseph Neulen, Kerstin Konrad, Beate Herpertz-Dahlmann, Cordian Beyer, Jochen Seitz
Regions of interest were digitally recorded using the Leica DM 6000 microscope (Leica microsystems, Bensheim, Germany). The numbers of GFAP-, Map2- and APC-positive cells were analysed by manual counting with ImageJ 3 software (1.48v, Wayne Rasband, National Institutes of Health) by two observers blinded to the groups, and the results were averaged and expressed as cells/mm2. Only cells with a visible nucleus were counted. Immunoreactive areas of GFAP and Map2 cells were determined with ImageJ software by quantifying the GFAP and Map2 signalling as the area in percent. For the corpus callosum analysis, recordings from three different regions (medial, sub cingulum and lateral) were averaged. Also three different areas (retrosplenial granular cortex, primary motor cortex and primary somatosensory cortex) were averaged for the cerebral cortex analysis.
Related Knowledge Centers
- Allocortex
- Cerebral Hemisphere
- Corpus Callosum
- Neocortex
- Nervous Tissue
- Cerebrum
- Brain
- Cortex
- Longitudinal Fissure
- Neuron