A method of reversible inactivation of small regions of brain tissue.
A method is described for reversibly inactivating small, precisely localized regions of brain tissue with injections of nanoliter quantities of the local anesthetic lidocaine hydrochloride. The injections are made through a combined recording-injection probe consisting of a glass micropipette onto whose outer surface is plated a metallic cylinder for recording extracellular action potentials. The recording cylinder for recording extracellular action potentials. The recording cylinder, located a known distance from the pipette tip, picks up a continuous, large-amplitude, multiunit response which can be used to accurately position the tip according to physiological criteria. It also provides a means of determining the duration of the anesthetic block and estimating its spreat. This devise has been used to selectively block 200--400 micrometers regions of individual laminae of the lateral geniculate nucleus centered within 50 micrometers of a retinotopically defined target site. The blocks last from 3 to 10 min and can be repeated many times at the same location.
D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D005829:Geniculate Bodies / Q000187:drug effects / Q000502:physiology*; D000882:Haplorhini; D008012:Lidocaine / Q000008:administration & dosage* / Q000494:pharmacology; D008839:Microelectrodes; D008845:Microinjections / Q000295:instrumentation*; D009482:Neurophysiology / Q000295:instrumentation / Q000379:methods; D013672:Technology
D008012:Lidocaine