Parvalbumin is calcium binding albumin protein, which binds two calcium ions. Parvalbumin has 3 EF hand motifs and is structurally related to calmodulin and troponin C. Pvalb is localized in fast-contracting muscles, where its levels are highest, in the brain and some endocrine tissues. Parvalbumin is found in GABAergic interneurons in the nervous system, primarily expressed by chandelier and basket cells in the cortex. Parvalbumin interneurons' connections are generally perisomatic (surrounding the cell body of neurons). In the hippocampus, PV+ interneurons are subdivided into basket, axo-axonic, bistratified, and oriens-lacunosum moleculare (O-LM) cells, each subtype targeting distinct domains of pyramidal cells. The majority of the Parvalbumin interneurons are fast-spiking, and are thought to generate gamma waves recorded in EEG. Pvalb -expressing interneurons represent roughly 25 % of GABA cells in the primate DLPFC. Decreased Parvalbumin and GAD67 expression was found in PV+ GABAergic interneurons in schizophrenia. Parvalbumin is identified as an allergen causing seafood allergy. Pvalb may have evolved from an ancestral four domain calcium binding protein Synonyms: Pvalb, Pva, PALB1, Parvalbumin.