Non-opioid nociceptive activity of human dynorphin mutants that cause neurodegenerative disorder spinocerebellar ataxia type 23

► Dynorphin A-R6W induces nociceptive responses in the mouse spinal cord. ► Dynorphin A-R6W-induced nociception was diminished by morphine and MK-801. ► Dynorphin A-R6W produces nociception via activation of NMDA receptor in mice.