Spatial learning in the genetically heterogeneous NIH-HS rat stock and RLA-I/RHA-I rats: revisiting the relationship with unconditioned and conditioned anxiety.
Physiol Behav
; 144: 15-25, 2015 May 15.
Article
em En
| MEDLINE
| ID: mdl-25747770
ABSTRACT
To characterize learning/memory profiles for the first time in the genetically heterogeneous NIH-HS rat stock, and to examine whether these are associated with anxiety, we evaluated NIH-HS rats for spatial learning/memory in the Morris water maze (MWM) and in the following anxiety/fear tests the elevated zero-maze (ZM; unconditioned anxiety), a context-conditioned fear test and the acquisition of two-way active avoidance (conditioned anxiety). NIH-HS rats were compared with the Roman High- (RHA-I) and Low-Avoidance (RLA-I) rat strains, given the well-known differences between the Roman strains/lines in anxiety-related behavior and in spatial learning/memory. The results show that (i) As expected, RLA-I rats were more anxious in the ZM test, displayed more frequent context-conditioned freezing episodes and fewer avoidances than RHA-I rats. (ii) Scores of NIH-HS rats in these tests/tasks mostly fell in between those of the Roman rat strains, and were usually closer to the values of the RLA-I strain. (iii) Pigmented NIH-HS (only a small part of NIH-HS rats were albino) rats were the best spatial learners and displayed better spatial memory than the other three (RHA-I, RLA-I and NIH-HS albino) groups. (iv) Albino NIH-HS and RLA-I rats also showed better learning/memory than the RHA-I strain. (v) Within the NIH-HS stock, the most anxious rats in the ZM test presented the best learning and/or memory efficiency (regardless of pigmentation). In summary, NIH-HS rats display a high performance in spatial learning/memory tasks and a passive coping strategy when facing conditioned conflict situations. In addition, unconditioned anxiety in NIH-HS rats predicts better spatial learning/memory.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ansiedade
/
Ratos Endogâmicos
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Especificidade da Espécie
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Heterogeneidade Genética
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Condicionamento Psicológico
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Aprendizagem Espacial
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Physiol Behav
Ano de publicação:
2015
Tipo de documento:
Article