Effects of intrathecal local anesthetics on spinal excitability and on the development of autotomy
Related Experiment Video
Updated: Aug 1, 2026

Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention
Published on: October 16, 2013
Lei Luo1, Zsuzsanna Wiesenfeld-Hallin
1Karolinska Institute, Department of Medical Laboratory Sciences and Technology, Section of Clinical Neurophysiology, Huddinge University Hospital, S-141 86 Huddinge, Sweden.
Abstract:
The effect of 500 micrograms intrathecal (i.t.) lidocaine and tocainide injected prior to unilateral sciatic nerve section on the development of autotomy behavior was examined in rats. Neither drug inhibited autotomy compared with saline controls. The effect of lidocaine and tocainide on the flexor reflex in decerebrate, spinalized rats was also examined. Both drugs at 500 micrograms i.t. totally blocked the flexor reflex and hyperexcitability following acute nerve section, with a longer duration of action with tocainide. Recovery from the drugs was followed by a prolonged period of reflex hyperexcitability, even without axotomy. Lower dose lidocaine (100 micrograms) briefly blocked the reflex and recovery was followed by reflex hyperexcitability. Very low dose i.t. lidocaine (1 and 10 micrograms) did not block the flexor reflex, but only induced a prolonged increase in reflex magnitude. The possible mechanisms underlying these observations are discussed. The results suggest that i.t. local anesthetic pretreatment alone may not be beneficial for the prevention of the development of postoperative or neuropathic pain.
Related Concept Videos
Local Anesthetics: Chemistry and Structure-Activity Relationship
Local Anesthetics: Mechanism of Action
Local anesthetics are amphiphilic molecules consisting of a hydrophobic aromatic part linked to a hydrophilic group by an ester or amide linkage. They are weak bases and are usually available as salts, which increases their solubility and stability. Once administered, LAs exist in the body either...
Local Anesthetics: Pharmacokinetics
Local Anesthetics: Differential Sensitivity of Nerve Fibers
Local Anesthetics: Clinical Application as Spinal Anesthesia
Local Anesthetics: Clinical Application as Epidural Anesthesia
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...

