Cell lines derived from hippocampal neurons of the normal and trisomy 16 mouse fetus (a model for Down syndrome) exhibit neuronal markers, cholinergic function, and functional neurotransmitter receptors

Abstract

We have established hippocampal cell lines from normal and trisomy 16 fetal mice, a model of human trisomy 21. Both cell lines, named H1b (derived from a normal animal) and HTk (trisomic) possess neuronal markers by immunohistochemistry (enolase, synaptophysin, microtubule associated protein-2, and choline acetyltransferase) and lack glial markers (glial fibrillary acidic protein and S-100). Also, we evaluated intracellular Ca2+ levels ([Ca2+]i) in response to neurotransmitter agonists, in cells loaded with the fluorescent Ca2+ indicators Indo-1 and Fluo-3. Both cell lines responded to glutamatergic stimuli induced by glutamate, N-methyl-D-aspartate, I-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazole propanoic acid or kainate. Glutamate responses were only partially prevented by addition of 5 mM EGTA and the metabotropic glutamate receptor agonist, trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid (ACPD), increased [Ca2+]i in both cell types. These results confirm the presence of glu