title: Lithium prevents REM sleep deprivation-induced impairments on memory consolidation.
abstract: BACKGROUND
  Pre-training rapid eye movement sleep (REMS) deprivation affects memory acquisition and/or consolidation. It also produces major REMS rebound at the cost of waking and slow wave sleep (SWS). Given that both SWS and REMS appear to be important for memory processes, REMS rebound after training may disrupt the organization of sleep cycles, i.e., excessive amount of REMS and/or little SWS after training could be harmful for memory formation.
  
  
  OBJECTIVE
  To examine whether lithium, a drug known to increase SWS and reduce REMS, could prevent the memory impairment induced by pre-training sleep deprivation.
  
  
  METHODS
  Animals were divided in 2 groups: cage control (CC) and REMS-deprived (REMSDep), and then subdivided into 4 subgroups, treated either with vehicle or 1 of 3 doses of lithium (50, 100, and 150 mg/kg) 2 h before training on the multiple trial inhibitory avoidance task. Animals were tested 48 h later to make sure that the drug had been already metabolized and eliminated. Another set of animals was implanted with electrodes and submitted to the same experimental protocol for assessment of drug-induced sleep-wake changes.
  
  
  METHODS
  Wistar male rats weighing 300-400 g.
  
  
  RESULTS
  Sleep deprived rats required more trials to learn the task and still showed a performance deficit during test, except from those treated with 150 mg/kg of lithium, which also reduced the time spent in REM sleep during sleep recovery.
  
  
  CONCLUSIONS
  Lithium reduced rapid eye movement sleep and prevented memory impairment induced by sleep deprivation. These results indicate that these phenomena may be related, but cause-effect relationship cannot be ascertained.
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Simone M
authors.initials: SM
authors.lastname: Ota
authors.forename: Karin Di Monteiro
authors.initials: KD
authors.lastname: Moreira
authors.forename: Deborah
authors.initials: D
authors.lastname: Suchecki
authors.forename: Maria Gabriela M
authors.initials: MG
authors.lastname: Oliveira
authors.forename: Paula A
authors.initials: PA
authors.lastname: Tiba
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D004569:Electroencephalography; D016651:Lithium Carbonate / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D012890:Sleep / Q000187:drug effects; D012892:Sleep Deprivation / Q000150:complications*
chemical_list: D016651:Lithium Carbonate
keywords: Multiple trial inhibitory avoidance task; lithium; sleep rebound; slow wave sleep