Calyx (anatomy) kidney, a conglomeration of two or three minor calyces to form a major calyx, or the Calyx of Held, a particularly large synapse in the mammalian auditory central nervous system, named by H. Held in his 1893 article "Die centrale Gehörleitung", due to its flower-petal-like shape. In male insects, a funnel-shaped expansion of the basal part of the "vas deferens" (part of the seminal duct). Also in entomology, a flattened cap of neuropile in an insect brain (a component of the corpus pedunculatum) and by certain female insects, an expansion of the oviduct into which the ovarioles open. Calyx (anatomy)
Calyx of Held calcium into the mitochondria, and providing energy for glutamate synthesis. Various glial cells are also associated with the calyx of Held. Two types of glial cells surround the calyx: astrocytes and NG glial cells. The astrocytes express glutamate transporters to remove glutamate from the synapse. This is the only known mechanism for removal of glutamate from the synapse. The NG glial cells express AMPA receptors. At postnatal day two (P2), the immature calyx of Held is formed, easily distinguished by its characteristic sealed-spoon morphology. The primary synaptic contacts that form the calyx are assembled between neurons of the MNTB (medial