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Haldan Keffer Hartline
Haldan Keffer Hartline (December 22, 1903 – March 17, 1983) was an American physiologist who was a co-recipient (with George Wald and Ragnar Granit) of the 1967 Nobel Prize in Physiology or Medicine for his work in analyzing the neurophysiological mechanisms of vision. Education Hartline did his undergraduate studies at Lafayette College in Easton, Pennsylvania, graduating in 1923. He began his study of retinal electrophysiology as a National Research Council Fellow at Johns Hopkins School of Medicine, receiving his medical degree in 1927. Career and research After attending the universities of Leipzig and Munich as an Eldridge Johnson traveling research scholar from the University of Pennsylvania, he returned to the US to take a position in the Eldridge Reeves Johnson Foundation for Medical Physics at Penn, which was under the directorship of Detlev W. Bronk at that time. In 1940–1941, he was Associate Professor of Physiology at Cornell Medical College in New York City, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloomsburg, Pennsylvania
Bloomsburg is a town and the county seat of Columbia County, Pennsylvania, United States. It is part of Northeastern Pennsylvania and is located southwest of Wilkes-Barre, Pennsylvania, Wilkes-Barre along the Susquehanna River. It is the only list of municipalities in Pennsylvania, Pennsylvania municipality incorporated as a town. As of the 2010 United States census, 2010 census, Bloomsburg had a population of 14,855, with an estimated population of 13,811 in 2019. Bloomsburg is one of two principal communities of the Bloomsburg-Berwick metropolitan area, Bloomsburg-Berwick, PA Metropolitan Statistical Area, a United States metropolitan area, metropolitan area that covers Columbia and Montour County, Pennsylvania, Montour counties, and had a combined population of 85,562 at the 2010 United States Census, 2010 census. History The first signs of European settlement date to the year 1772, when James McClure established a log cabin in the area. Until the mid-19th century, it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Maximilian University Of Munich
The Ludwig Maximilian University of Munich (simply University of Munich or LMU; german: Ludwig-Maximilians-Universität München) is a public research university in Munich, Germany. It is Germany's sixth-oldest university in continuous operation. Originally established in Ingolstadt in 1472 by Duke Ludwig IX of Bavaria-Landshut, the university was moved in 1800 to Landshut by King Maximilian I of Bavaria when the city was threatened by the French, before being relocated to its present-day location in Munich in 1826 by King Ludwig I of Bavaria. In 1802, the university was officially named Ludwig-Maximilians-Universität by King Maximilian I of Bavaria in honor of himself and Ludwig IX. LMU is currently the second-largest university in Germany in terms of student population; in the 2018/19 winter semester, the university had a total of 51,606 matriculated students. Of these, 9,424 were freshmen while international students totalled 8,875 or approximately 17% of the student pop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Inhibition
In neurobiology, lateral inhibition is the capacity of an excited neuron to reduce the activity of its neighbors. Lateral inhibition disables the spreading of action potentials from excited neurons to neighboring neurons in the lateral direction. This creates a contrast in stimulation that allows increased sensory perception. It is also referred to as lateral antagonism and occurs primarily in visual processes, but also in tactile, auditory, and even olfactory processing. Cells that utilize lateral inhibition appear primarily in the cerebral cortex and thalamus and make up lateral inhibitory networks (LINs). Artificial lateral inhibition has been incorporated into artificial sensory systems, such as vision chips, hearing systems, and optical mice. An often under-appreciated point is that although lateral inhibition is visualised in a spatial sense, it is also thought to exist in what is known as "lateral inhibition across abstract dimensions." This refers to lateral inhibition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoreceptor Cell
A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential. There are currently three known types of photoreceptor cells in mammalian eyes: rods, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form an image of the environment, sight. Rods primarily mediate scotopic vision (dim conditions) whereas cones primarily mediate to photopic vision (bright conditions), but the processes in each that supports phototransduction is similar. A third class of mammalian photoreceptor cell was discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optic Nerve
In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial nerve that transmits visual system, visual information from the retina to the brain. In humans, the optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells; it extends from the optic disc to the optic chiasma and continues as the optic tract to the lateral geniculate nucleus, Pretectal area, pretectal nuclei, and superior colliculus. Structure The optic nerve has been classified as the second of twelve paired cranial nerves, but it is technically part of the central nervous system, rather than the peripheral nervous system because it is derived from an out-pouching of the diencephalon (optic stalks) during embryonic development. As a consequence, the fibers of the optic nerve are covered with myelin produced by oligodendrocytes, rather than Schwann cells of the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlantic Horseshoe Crab
The Atlantic horseshoe crab (''Limulus polyphemus''), also known as the American horseshoe crab, is a species of marine and brackish chelicerate arthropod. Despite their name, horseshoe crabs are more closely related to spiders, ticks, and scorpions than to crabs. It is found in the Gulf of Mexico and along the Atlantic coast of North America. The main area of annual migration is Delaware Bay along the South Jersey Delaware Bayshore. Their eggs were eaten by Native Americans, but today Atlantic horseshoe crabs are caught for use as fishing bait, in biomedicine (especially for ''Limulus'' amebocyte lysate) and science. They play a major role in the local ecosystems, with their eggs providing an important food source for shorebirds, and the juveniles and adults being eaten by sea turtles. The other three extant (living) species in the family Limulidae are also called horseshoe crabs, but they are restricted to Asia. Names and classification This group of animals is also known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horseshoe Crab
Horseshoe crabs are marine and brackish water arthropods of the family Limulidae and the only living members of the order Xiphosura. Despite their name, they are not true crabs or crustaceans: they are chelicerates, most closely related to arachnids, such as spiders and scorpions. Horseshoe crabs live primarily in and around shallow coastal waters on soft, sandy or muddy bottoms. They are generally found in the intertidal zone at spring high tides. They are eaten in some parts of Asia, and used as fishing bait, in fertilizer and in science (especially ''Limulus'' amebocyte lysate). In recent years, population declines have occurred as a consequence of coastal habitat destruction and overharvesting. Tetrodotoxin may be present in one horseshoe crab species, '' Carcinoscorpius rotundicauda''. Fossil records for horseshoe crabs extend back as far as 480 million years ago, with extant forms being living fossils. A 2019 molecular analysis places them as the sister group of Ricinule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual System
The visual system comprises the sensory organ (the eye) and parts of the central nervous system (the retina containing photoreceptor cells, the optic nerve, the optic tract and the visual cortex) which gives organisms the sense of sight (the ability to perception, detect and process visible light) as well as enabling the formation of several non-image photo response functions. It detects and interprets information from the optical spectrum perceptible to that species to "build a representation" of the surrounding environment. The visual system carries out a number of complex tasks, including the reception of light and the formation of monocular neural representations, colour vision, the neural mechanisms underlying stereopsis and assessment of distances to and between objects, the identification of a particular object of interest, motion perception, the analysis and integration of visual information, pattern recognition, accurate motor coordination under visual guidance, and mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () ( chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rods and cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible for the perception of colour through the use of a range of opsins, as well as high-acuity vision used for task ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
