Hippocalcin is a Ca2+-binding protein, which belongs to the family of neuronal Cahe brain have not been investigated in detail. the brain have not been investigated in detail. Th e molecular mechanism, by which hippocalcin operates, is thought to be a Ca2+-myristoyl switch (Burgoyne, 2007). Hippocalcin is N-terminally myristoylated and myristoyl group is sequestered in the Ca2+ free form of the protein and following Ca2+-binding a substantial conformational change allows extrusion of the lipophilic myristoyl group (Ames et al., 1997) resulting in the protein translocation from cytosol to membranes. It is obvious that neurons might use this property of hippocalcin in signal transduction processes (Kobayashi et al., 1993; O'Callaghan et al., 2003). Hippocalcin as well as other neuronal Ca2+ sensor proteins are discussed to play many roles in calcium-dependent signal transduction of physiological and pathological processes in the central nervous system. In spite of clear importance of hippocalcindependent processes in neuronal functioning hippocalcin translocation during intrinsic neuronal activity in living hippocampal neurons have not been investigated yet. Recently we have observed spontaneous translocation of hippocalcin tagged by Yellow Fluorescent Protein (HPCA-YFP) in dendrites of hippocampal neurons growing in primary cultures (Markova et al., 2008). In the present short report we have studied spatio-temporal profi les of this translocation.