Neuronal (bi)polarity as a self-organized process with membrane growth

SILVIA A. MENCHÓN; GÄRTNER, ANNETTE; ROMÁN, PABLO; DOTTI, CARLOS

Congreso; European Biophysics Congress; 2011

Polarization refers to the asymmetric changes in cellular organization in response to external or internal signals. Neuronal polarization begins with the growth of a single neurite shortly after cell division, followed by the growth of a second neurite at the opposite pole. This early bipolar shape is critical for brain function, as it defines axis of migration and consequently proper three dimensional organization and nerve circuitry. However, it is not known if a direct relationship exists between the formation of the second, opposite, neurite and the mechanisms involved in the formation of the first. We tackled this issue through mathematical modeling, based on membrane traffic (exocytosis-endocytosis), and lateral diffusion. With this approach, we demonstrated that a single pole of molecular asymmetry is sufficient to induce a second one at the opposite side, upon induction of growth from the first pole. Our work gives mathematical proof that the occurrence of a single asymmetry in a round cell is sufficient to warrant morphological bipolarism.