title: Characterization of the sleep-wake cycle of the Neotropical rodent Proechimys guyannensis.
abstract: OBJECTIVE
  To better understand the sleep-wake cycle characteristics in the female Neotropical rodent Proechimys guyannensis related to comparative neurobiology.
  
  
  METHODS
  Surface neocortical and hippocampal electrodes were chronically implanted in the brains of female Wistar and Proechimys animals. In addition, electrodes for the study of muscle activity were implanted into the neck muscle of both species. After surgical recovery and a period of adaptation, animals were continuously registered for periods as long as 48 h.
  
  
  RESULTS
  In both the light and dark phases of the cycle, significant differences in some electrographic patterns were observed between the Proechimys and Wistar animals. Although Proechimys has nocturnal activities and a pattern of polyphasic sleep similar to Wistar rats, the analysis of its sleep-wakefulness cycle indicates that the Neotropical rodent sleeps less with consequent longer periods of wakefulness when compared to Wistar rats.
  
  
  CONCLUSIONS
  Together with previous findings of different neuroanatomical, neurophysiologic and behavioral characteristics, this study allow us to better understand adaptive differences of the Neotropical rodent Proechimys.
authors.affiliation: Disciplina de Neurologia Experimental/Departamento de Neurologia e Neurocirurgia, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: José Cláudio
authors.initials: JC
authors.lastname: da Silva
authors.affiliation: Departamento de Psicobiologia, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: de Matos Barbosa Pimenta
authors.affiliation: Departamento de Psicobiologia, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Monica Levy
authors.initials: ML
authors.lastname: Andersen
authors.affiliation: Departamento de Fisiologia Cardiovascular e Respiratória, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Gerhardus Hermanus Maria
authors.initials: GH
authors.lastname: Schoorlemmer
authors.affiliation: Departamento de Psicobiologia, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Tufik
authors.affiliation: Disciplina de Neurologia Experimental/Departamento de Neurologia e Neurocirurgia, Escola Paulista de Medicina/UNIFESP, Sao Paulo, Brazil.
authors.forename: Esper Abrão
authors.initials: EA
authors.lastname: Cavalheiro
keywords: Proechimys; Sleep; Wistar; electrographic recordings