Characterization of Spatial Learning and Sickness Responses in Aging Rats Following Recurrent Lipopolysaccharide Administration.
Biol Res Nurs
; 22(1): 92-102, 2020 01.
Article
em En
| MEDLINE
| ID: mdl-31601118
ABSTRACT
Infections in older individuals can result in cognitive function decline, yet research is limited on how recurrent infections affect cognitive responses. Activation of the immune system results in sickness responses mediated by cytokines. This pilot study examined effects of a model of recurrent infection in aged, male Brown Norway rats on sickness responses, including spatial learning, and cytokine levels. To model initial and recurrent infection, 300 µg/kg lipopolysaccharide (LPS) or saline was administered 1/day for 2 consecutive days during 2 weeks separated by 16 days. Testing occurred for 6 days during each LPS injection week using the Morris water maze, a measure used to evaluate spatial learning. Directional heading error (DHE) and swim time latency served as spatial learning indices. Retention tests and probe trials assessed memory. Plasma cytokine levels were assessed 5 and 24 hr after each LPS injection during Week 2. While food intake and weight decreased significantly in LPS-injected rats compared to controls during Week 1, both displayed increased DHE. Despite exhibiting lessened sickness behaviors during Week 2, experimental animals still displayed spatial learning deficits. Probe trials revealed memory deficits in LPS-injected animals. Interleukin 6 level was higher in the experimental group 5 and 24 hr after LPS injection on Day 1 compared to Day 2 and higher in the experimental compared to the control group at 5 hr on Day 1. Cognitive effects were dissociated from metabolic effects in aged rats, with recurring LPS exposure resulting in persistent cognitive impairment despite decreased sickness responses. Further research with older individuals is warranted.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lipopolissacarídeos
/
Interleucina-6
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Aprendizagem em Labirinto
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Comportamento de Doença
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Aprendizagem Espacial
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Transtornos da Memória
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Biol Res Nurs
Assunto da revista:
ENFERMAGEM
/
MEDICINA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos