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Tufted Cell
Tufted cells are found within the olfactory glomeruli. They receive input from the receptor cells of the olfactory epithelium found in areas of the nose able to sense smell. Both tufted cells and mitral cells are projection neurons. Projection neurons send the signals from the glomeruli deeper into the brain. The actual signal sent through these projection cells has been sharpened or filtered by a process called lateral inhibition. Both the periglomerular cells and the granule cells contribute to lateral inhibition. Projection neurons therefore transmit a sharpened olfactory signal to the deeper parts of the brain. Tufted cells project onto the anterior piriform cortex. See also *Mitral cell Mitral cells are neurons that are part of the olfactory system. They are located in the olfactory bulb in the mammalian central nervous system. They receive information from the axons of olfactory receptor neurons, forming synapses in neuropils ...—Another neuron in the olfactory glomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glomerulus (olfaction)
The glomerulus (: glomeruli) is a spherical structure located in the olfactory bulb of the brain where synapses form between the terminals of the olfactory nerve and the dendrites of mitral, periglomerular and tufted cells. Each glomerulus is surrounded by a heterogeneous population of juxtaglomerular neurons (that include periglomerular, short axon, and external tufted cells) and glial cells. All glomeruli are located near the surface of the olfactory bulb. The olfactory bulb also includes a portion of the anterior olfactory nucleus, the cells of which contribute fibers to the olfactory tract. They are the initial sites for synaptic processing of odor information coming from the nose. A glomerulus is made up of a globular tangle of axons from the olfactory receptor neurons, and dendrites from the mitral and tufted cells, as well as, from cells that surround the glomerulus such as the external tufted cells, periglomerular cells, short axon cells, and astrocytes. In mammals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory Epithelium
The olfactory epithelium is a specialized epithelium, epithelial tissue inside the nasal cavity that is involved in olfaction, smell. In humans, it measures and lies on the roof of the nasal cavity about above and behind the nostrils. The olfactory epithelium is the part of the olfactory system directly responsible for detecting odors. Structure Olfactory epithelium consists of four distinct cell types: * Olfactory receptor neuron, Olfactory sensory neurons * Supporting cells * Basal cells * Brush cells Olfactory sensory neurons The olfactory receptor neurons are sensory neurons of the olfactory epithelium. They are bipolar neurons and their apical poles express odorant receptors on cilium, non-motile cilia at the ends of the dendritic knob, which extend out into the airspace to interact with odorants. Odorant receptors bind odorants in the airspace, which are made soluble by the serous secretions from olfactory glands located in the lamina propria of the mucosa.Ross, MH, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projection Neuron
Projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord. In human neuroanatomy, bundles of axons (nerve fibers) called nerve tracts, within the brain, can be categorized by their function into association tracts, projection tracts, and commissural tracts. In the neocortex, projection neurons are excitatory neurons that send axons to distant brain targets. Considering the six histologically distinct layers of the neocortex, ''associative projection neurons'' extend axons within one cortical hemisphere; ''commissural projection neurons'' extend axons across the midline to the contralateral hemisphere; and ''corticofugal projection neurons'' extend axons away from the cortex. That said, some neurons are multi-functional and can therefore be categorized into more than one such category. Efferent The principal efferent fibers are: * (1) the motor tract, occupying the genu and anterior two-thirds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piriform Cortex
The piriform cortex, or pyriform cortex, is a region in the brain, part of the rhinencephalon situated in the cerebrum. The function of the piriform cortex relates to the sense of smell. Structure The piriform cortex is part of the rhinencephalon situated in the cerebrum. In human anatomy, the piriform cortex has been described as consisting of the cortical amygdala, uncus, and anterior parahippocampal gyrus. More specifically, the human piriform cortex is located between the insula and the temporal lobe, anteriorly and laterally of the amygdala.Howard, J. D., Plailly, J., Grueschow, M., Haynes, J. D., & Gottfried, J. A. (2009). Odor quality coding and categorization in human posterior piriform cortex. Nature neuroscience, 12(7), 932-938. Supplementary material, p.4 Function The function of the piriform cortex relates to olfaction, which is the perception of smell. This has been particularly shown in humans for the posterior piriform cortex. The piriform cortex in rodents a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory Bulb Mitral Cell
Mitral cells are neurons that are part of the olfactory system. They are located in the olfactory bulb in the mammalian central nervous system. They receive information from the axons of olfactory receptor neurons, forming synapses in neuropils called glomeruli. Axons of the mitral cells transfer information to a number of areas in the brain, including the piriform cortex, entorhinal cortex, and amygdala. Mitral cells receive excitatory input from olfactory sensory neurons and external tufted cells on their primary dendrites, whereas inhibitory input arises either from granule cells onto their lateral dendrites and soma or from periglomerular cells onto their dendritic tuft. Mitral cells together with tufted cells form an obligatory relay for all olfactory information entering from the olfactory nerve. Mitral cell output is not a passive reflection of their input from the olfactory nerve. In mice, each mitral cell sends a single primary dendrite into a glomerulus receiving input ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory System
The olfactory system, is the sensory nervous system, sensory system used for the sense of smell (olfaction). Olfaction is one of the special senses directly associated with specific organs. Most mammals and reptiles have a main olfactory system and an accessory olfactory system. The main olfactory system detects airborne substances, while the accessory system senses fluid-phase stimuli. The senses of smell and taste (gustatory system) are often referred to together as the chemosensory system, because they both give the brain information about the chemical composition of objects through a process called transduction (physiology), transduction. Structure Peripheral The peripheral olfactory system consists mainly of the nostrils, ethmoid bone, nasal cavity, and the olfactory epithelium (layers of thin tissue covered in mucus that line the nasal cavity). The primary components of the layers of epithelial tissue are the mucous membranes, olfactory glands, olfactory receptor neurons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
