Hemiellipsoid bodies: neural plasticity in the crab's "mushroom bodies"

FRANCISCO JAVIER MAZA; FERNANDO LOCATELLI; AVISHAG SHKEDY; JULIETA SZTARKER; ALEJANDRO DELORENZI

Mar del Plata

Congreso; XXX Reunión Anual de la Sociedad Argentina de Investigación en Neurociencias; 2015

Sociedad Argentina de Investigación en Neurociencias

The corpora pedunculata (or mushroom bodies) are complex paired structures in the brain of various invertebrate species and vastly studied in insects. Since their first description in the mid-1850, the corpora pedunculata were considered as higher-order brain centers involved in sensory integration and memory. Although morphologically diverse, a corpora pedunculata common ground plan was described across different invertebrates. Moreover, it has been proposed that the mushroom bodies and the vertebrate pallium evolved from the same structure in a common ancestor circa 600 million years ago. In crustaceans, neuropils sharing a similar ground pattern with the corpora pedunculata are the Hemiellipsoid bodies (HBs), which have been proposed to have an evolutionary common origin. Our group´s works in the crab Neohelice granulata shows morphological and immunohistochemical studies that parallel the results for well described HBs in other crustaceans, allowing an accurate identification of this neuropil in this crab (see poster Shkedy:au). Here we evaluate, in the crab N. granulata, context-signal memory related neural plasticity of the intrinsic neurons of the crab´s HBs by in vivo calcium imaging. We found neuronal responses to mechanical and visual stimulation and stimulus specific changes during and after training. These results provide the first in vivo physiologicalevidence that support the idea that the HBs, the crustaceans´ mushroom bodies, are involved in memory processes.