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  2. Neuromelanin - Wikipedia

    en.wikipedia.org/wiki/Neuromelanin

    Neuromelanin gives specific brain sections, such as the substantia nigra or the locus coeruleus, distinct color. It is a type of melanin and similar to other forms of peripheral melanin. It is insoluble in organic compounds, and can be labeled by silver staining. It is called neuromelanin because of its function and the color change that ...

  3. Melanin - Wikipedia

    en.wikipedia.org/wiki/Melanin

    In the brain, tissues with melanin include the medulla and pigment-bearing neurons within areas of the brainstem, such as the locus coeruleus. It also occurs in the zona reticularis of the adrenal gland. [18] The melanin in the skin is produced by melanocytes, which are found in the basal layer of the epidermis. Although, in general, human ...

  4. Corpora arenacea - Wikipedia

    en.wikipedia.org/wiki/Corpora_arenacea

    Corpora arenacea (singular: corpus arenaceum, [1] also called brain sand or acervuli [2] [3] or psammoma bodies [4] or pineal concretions [4]) are calcified structures in the pineal gland and other areas of the brain such as the choroid plexus. Older organisms have numerous corpora arenacea, whose function, if any, is unknown.

  5. Rod cell - Wikipedia

    en.wikipedia.org/wiki/Rod_cell

    When light hits photoreceptive pigments within the photoreceptor cell, the pigment changes shape. The pigment, called rhodopsin (conopsin is found in cone cells) comprises a large protein called opsin (situated in the plasma membrane), attached to which is a covalently bound prosthetic group: an organic molecule called retinal (a derivative of ...

  6. Calcium in biology - Wikipedia

    en.wikipedia.org/wiki/Calcium_in_biology

    The US Institute of Medicine (IOM) established Recommended Dietary Allowances (RDAs) for calcium in 1997 and updated those values in 2011. [6] See table. The European Food Safety Authority (EFSA) uses the term Population Reference Intake (PRIs) instead of RDAs and sets slightly different numbers: ages 4–10 800 mg, ages 11–17 1150 mg, ages 18–24 1000 mg, and >25 years 950 mg. [10]

  7. Melanopsin - Wikipedia

    en.wikipedia.org/wiki/Melanopsin

    Melanopsin is a type of photopigment belonging to a larger family of light-sensitive retinal proteins called opsins and encoded by the gene Opn4. [5] In the mammalian retina, there are two additional categories of opsins, both involved in the formation of visual images: rhodopsin and photopsin (types I, II, and III) in the rod and cone photoreceptor cells, respectively.

  8. Unlike other photoreceptor pigments, melanopsin has the ability to act as both the excitable photopigment and as a photoisomerase. Unlike the visual opsins in rod cells and cone cells , which rely on the standard visual cycles for recharging all-trans -retinal back into the photosensitive 11-cis -retinal , melanopsin is able to isomerize all ...

  9. Pigment dispersing factor - Wikipedia

    en.wikipedia.org/wiki/Pigment_dispersing_factor

    Pigment dispersing factor (pdf) is a gene that encodes the protein PDF, which is part of a large family of neuropeptides. [1] Its hormonal product, pigment dispersing hormone (PDH), was named for the diurnal pigment movement effect it has in crustacean retinal cells upon its initial discovery in the central nervous system of arthropods. [1]