Intrathecal morphine in mice: A new technique

A simple, rapid technique for intrathecal injections by lumbar puncture in unanesthetized mice is described. Intrathecal [3H]morphine base was not found in significant quantitities in either the midbrain or forebrain. Submicrogram quantities of morphine sulfate induced Straub tail response and tail-flick analgesia. These effects were dose related and antagonized by subcutaneous naloxone.