Effective spread and timecourse of neural inactivation caused by lidocaine injection in monkey cerebral cortex

J Neurosci Methods. 1997 Jun 6;74(1):17-26. doi: 10.1016/s0165-0270(97)02229-2.


We studied the effective spread of lidocaine to inactivate neural tissue in the frontal cortex of the rhesus monkey. Injections of 2% lidocaine at 4 microl/min were made while units were recorded 1 or 2 mm away. To inactivate units 1 mm away from the injection site 100% of the time, 7 microl of lidocaine had to be injected. To inactivate units 2 mm away from the injection site 100% of the time, 30 microl of lidocaine were required. Units were maximally inactivated around 8 min after the start of a lidocaine injection, and they gradually recovered, regaining most of their initial activity by around 30 min after the start of an injection. The volume of lidocaine required to inactivate neurons > 90% of the time could be estimated by the spherical volume equation, V = 4/3 pi (r)3. To prolong the inactivation, a slower infusion of lidocaine subsequent to an initial bolus was effective. Saline control injections had no effect. These results allow both a prediction of the timecourse of neural inactivation and an estimate of the spread of neural inactivation following injection of lidocaine into the monkey cerebral cortex.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cerebral Cortex / anatomy & histology
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiology*
  • Infusions, Parenteral / instrumentation
  • Infusions, Parenteral / methods
  • Lidocaine / administration & dosage
  • Lidocaine / pharmacology*
  • Macaca mulatta
  • Microinjections / instrumentation
  • Microinjections / methods
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / physiology*
  • Probability
  • Time Factors


  • Lidocaine