Individual Differences In The Forced Swimming Test And The Effect Of Environmental Enrichment: Searching For An Interaction
Fecha
2014-02-05
Tipo
artículo original
Autores
Sequeira Cordero, Andrey
Mora Gallegos, Andrea
Cuenca Berger, Patricia
Fornaguera Trías, Jaime
Título de la revista
ISSN de la revista
Título del volumen
Editor
Neuroscience 265(1):95-107
Resumen
Animals with low and high immobility in the forced
swimming test (FST) differ in a number of neurobehavioral
factors. A growing body of evidence suggests that the exposure
to enriched environments mediates a number of
changes in the brain. Therefore, we studied if animals’ individuality
can somehow modulate the response to environmental
stimuli. Male rats were classified according to their
immobility time scores in theFSTtest session as animals with
low, medium or high immobility. Then, rats from groups with
low and high immobility were randomly distributed in two
groups to be reared in different housing conditions (i.e.,
enriched and standard conditions) during 8 weeks. Animals
were subjected to the open field test (OFT) before and
6 weeks after the start of housing protocol. Rats with high
immobility in the FST also showed high ambulation and high
rearing time in the first OFT. Such findings were not observed
in the second OFT. Conversely, an effect of environmental
enrichment was found in the second OFT where enriched animals
showed lower ambulation and higher grooming time
than the standard control group. Rats were sacrificed after
the housing protocol and neurochemical content and/or gene
expression were studied in three different brain regions: the
prefrontal cortex, the hippocampus and the nucleus accumbens.
Rats with low immobility showed significantly higher
accumbal 5-HT levels than animals with high immobility,
whereas no neurochemical differences were observed
between enriched and standard animals. Regarding expression
data, however, an effect of enrichment on accumbal corticotropin-releasing factor (CRF) and its receptor 1 (CRFR1)
levels was observed, and such effect depended on immobility
levels. Thus, our results not only allowed us to identify a number
of differences between animals with low and high immobility
or animals housed in standard and enriched
conditions, but also suggested that animals’ individuality
modulated in some way the response to environmental stimuli.
Descripción
artículo -- Universidad de Costa Rica, Centro de Investigación en Neurociencias e
Instituto de Investigaciones en Salud. 2014. Este documento es privado debido a limitaciones de derechos de autor.
Palabras clave
environmental enrichment, neurotransmitters, gene expression, nucleus accumbens