The microtubule-associated protein (MAP) tau is found primarily in neurons and errors in its regulation are associated with Alzheimer's disease and other neurodegenerative disorders. Tau expression is transcriptionally regulated and tissue-specific. In this study, starting with a approximately 7500-bp fragment from the mouse tau gene, which includes tau exon -1, we define regions preferentially conferring tissue-specific expression. Furthermore, gel shift assays indicate that transcriptional regulators SP-1 and AP-2 are important for basal expression but not necessary for neuron-specific expression of the tau transcript.