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

FRANCISCO JAVIER MAZA; FERNANDO LOCATELLI; AVISAHG SHKEDY; ALEJANDRO DELORENZI

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

SAN

Hemiellipsoid bodies:neural plasticity in the crab´s "mushroom bodies" Maza,FJ;  Locatelli, F; Shkedy A.; Delorenzi A. The corporapedunculata (or mushroom bodies) are complex paired structures in the brain ofvarious invertebrate species and vastly studied in insects. Since their firstdescription in the mid-1850, the corpora pedunculata were considered ashigher-order brain centers been involved in sensory integration and memory.Although morphologically diverse, a corpora pedunculata common ground planacross diferent taxa was described. Moreover, it has been proposed that themushroom bodies and the vertebrate pallium evolved from the same structure in acommon ancestor circa 600 million years ago. In crustaceans, neuropils sharinga similar ground pattern with the corpora pedunculata are the Hemiellipsoid bodies(HBs), which have been proposed to have an evolutionary common origin. Ourgroup´s works in the crab Neohelice granulata shows morphological andimmunohistochemical studies that parallel the results for well described HBs ofother crustaceans, allowing an accurate identification of this neuropil in thiscrab (look for poster in the present meeting). Here we evaluate, in the crab N.granulata, context-signal memory related neural plasticity of the intrinsicneurons of the crab´s HBs by in vivo calcium imaging. We found neuronalresponses to mechanical and visual stimulation and stimulus specific changesduring and after training. These results provide the first in vivophysiological evidence that support the idea that the HBs of crustaceans areinvolved in memory processes.