In situ and immunocytochemical localization of E-FABP mRNA and protein during neuronal migration and differentiation in the rat brain

The present study compares the temporal-spatial expression and tissue local ization of the rat epidermal type fatty acid binding protein (E-FABP) (DA11 /C-FABP/S-FABP/LEBP/KLBP) in the developing rat central nervous system (CNS ). In situ hybridization (ISI-I) and immunocytochemistry (ICC) studies demo nstrate that mRNA E-FABP and protein are expressed at high levels during ne urogenesis, neuronal migration, and terminal differentiation. Migrating pyr amidal cells in the cerebral cortex, Purkinje cells and deep nuclear neuron s in the cerebellum, and neurons in the olfactory bulb and retina exhibited a strong E-FABP-like immunoreactivity (E-FABP-LI) throughout the entire pr ocess of differentiation and migration. The levels of E-FABP mRNA and prote in were dramatically higher in prenatal and early postnatal neurons, as com pared to adult neurons. The E-FABP antibody immunoreacted with growing neur ites, and nuclear and cytoplasmic regions of neurons. The intracellular mul tiregional pattern of localization of E-FABP and its differential temporal expression during development, are consistent with its proposed role in tra nsporting long chain free fatty acids and/or other hydrophobic ligands duri ng neuronal differentiation and axon growth, (C) 2000 Elsevier Science B.V, All rights reserved.