Data/hora: 16/06/2024 09:25:45

Provedor de dados: | 56
País: | Brazil
Título: | Sleep pattern and learning in knockdown mice with reduced cholinergic neurotransmission
Autores: | Queiroz,C.M.; Tiba,P.A.; Moreira,K.M.; Guidine,P.A.M.; Rezende,G.H.S.; Moraes,M.F.D.; Prado,M.A.M.; Prado,V.F.; Tufik,S.; Mello,L.E.
Data: | 2013-10-01
Ano: | 2013
Palavras-chave: | Sleep-wake cycle; Intermediate sleep; Acetylcholine; Contextual fear conditioning; Memory; Neurodegenerative disorders.
Resumo: | Impaired cholinergic neurotransmission can affect memory formation and influence sleep-wake cycles (SWC). In the present study, we describe the SWC in mice with a deficient vesicular acetylcholine transporter (VAChT) system, previously characterized as presenting reduced acetylcholine release and cognitive and behavioral dysfunctions. Continuous, chronic ECoG and EMG recordings were used to evaluate the SWC pattern during light and dark phases in VAChT knockdown heterozygous (VAChT-KDHET, n=7) and wild-type (WT, n=7) mice. SWC were evaluated for sleep efficiency, total amount and mean duration of slow-wave, intermediate and paradoxical sleep, as well as the number of awakenings from sleep. After recording SWC, contextual fear-conditioning tests were used as an acetylcholine-dependent learning paradigm. The results showed that sleep efficiency in VAChT-KDHET animals was similar to that of WT mice, but that the SWC was more fragmented. Fragmentation was characterized by an increase in the number of awakenings, mainly during intermediate sleep. VAChT-KDHET animals performed poorly in the contextual fear-conditioning paradigm (mean freezing time: 34.4±3.1 and 44.5±3.3 s for WT and VAChT-KDHET animals, respectively), which was followed by a 45% reduction in the number of paradoxical sleep episodes after the training session. Taken together, the results show that reduced cholinergic transmission led to sleep fragmentation and learning impairment. We discuss the results on the basis of cholinergic plasticity and its relevance to sleep homeostasis. We suggest that VAChT-KDHET mice could be a useful model to test cholinergic drugs used to treat sleep dysfunction in neurodegenerative disorders.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013001000844
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/1414-431X20133102
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.46 n.10 2013
Fonte: | info:eu-repo/semantics/openAccess