title: Lidocaine, tetrodotoxin and their effect on consolidation of spatial memory.
abstract: This study was aimed at comparing the effect of unilateral hippocampal inactivation with tetrodotoxin (TTX) and lidocaine on spatial memory consolidation. Both drugs block voltage-dependent sodium channels. However, TTX and lidocaine differ in the duration of their effects, with maximum TTX effect between 30 min and 120 min, washing out in 24 hours. Lidocaine maximum effect occurs 20-30 minutes after administration. Our experimental subjects, twenty-four 3-month-old Wistar rats, were unilaterally implanted with stainless-steel cannulae aimed at the right dorsal hippocampus. Animals received four daily trials for 5 consecutive days. Control injections of 1 microl saline, or inactivating injections of 5 ng of TTX in 1 microl saline or lidocaine (2%) in 1 microl were made through a guide cannula 1 minute after the last trial from day 1 to day 4. Results showed that the groups that received TTX or lidocaine did not differ but were impaired regarding controls, suggesting that short-term consolidation processes can account for the memory impairment observed here.
authors.affiliation: Universidad de Almería, Facultad de Psicología, Almería, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Cimadevilla
authors.forename: Francisco
authors.initials: F
authors.lastname: López
authors.forename: Luz
authors.initials: L
authors.lastname: Nieto
authors.forename: Ma Jesús
authors.initials: MJ
authors.lastname: Aguirre
authors.forename: Rubén
authors.initials: R
authors.lastname: Fernández
mesh_terms: D000818:Animals; D008012:Lidocaine / Q000009:adverse effects / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D008569:Memory Disorders / Q000139:chemically induced; D051381:Rats; D017208:Rats, Wistar; D026941:Sodium Channel Blockers / Q000009:adverse effects / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000009:adverse effects / Q000494:pharmacology*
chemical_list: D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; D008012:Lidocaine