Biochemical analyses of tau and other neuronal markers in the submandibular gland and frontal cortex across stages of Alzheimer disease

•Select tau species and other neuronal proteins are detected in the submandibular gland of human cases.•The evaluated neuronal proteins experience differential protein levels based on anatomic region (submandibular gland or frontal cortex) and clinicopathological stage of AD.•Tissues innervated by the peripheral nervous system may experience unique selective vulnerabilities in AD.