Tissue printed cells from teleost electrosensory and cerebellar structures

Abstract

A modification of the tissue printing technique was used to acutely isolate and culture cells from the electrosensory lateral line lobe (ELL), corpus cerebelli (CCb), and eminentia granularis pars posterior (EGp) of the adult weakly electric fish, Apteronotus leptorhynchus. Cells were isolated without the use of proteolytic enzymes and tissue printed as a monolayer onto glass coverslips through centrifugation in the presence of a medium designed to preserve cell structure. Tissue printed cells were reliably distributed in an organotypic fashion that allowed for the identification of anatomical boundaries between the ELL and cerebellar regions, distinct sensory maps in the ELL, and specific cell laminae. Many cells were isolated with an excellent preservation of soma-dendritic structure, permitting direct identification of all electrosensory cell classes according to morphological or immunocytochemical criteria. Several classes of glial cells were isolated, including small diameter microglia and the complex arborizations of oligodendrocytes. A plexus of fine processes were often isolated in conjunction with cell somata and dendrites, potentially preserving synaptic contacts in vitro. In particular, immunolabel for gamma-aminobutyric acid (GABA) revealed a previously unrecognized network of GABAergic axonal processes in the CCb and EGp granule cell body and molecular layers. Tissue printed cells were readily maintained with an organotypic distribution of glial and neuronal elements for up to 27 days in culture. This procedure will allow for the isolation of electrosensory cells from adult central nervous system for electrophysiological analyses of membrane properties or synaptic interactions between identified cells.