Article

The Roman High- and Low-Avoidance rat strains differ in fear-potentiated startle and classical aversive conditioning

Psicothema, ISSN 0214-9915, Vol. 21, Nº. 1, 2009, pags. 27-32
Source: OAI

ABSTRACT

Las cepas de ratas Roman de alta y baja evitación difieren en respuesta de sobresalto potenciada por miedo y en condicionamiento clásico aversivo. Las sublíneas suizas de ratas Romanas «High»- (RHA/Verh) y «Low»-(RLA/Verh) «Avoidance» han sido seleccionadas genéticamente, desde 1972, en función de su excelente (RHA) o extremadamente pobre adquisición de la tarea de evitación activa en dos sentidos. Cepas consanguíneas (RHA-I y RLA-I), derivadas de las dos líneas anteriores, se mantienen en nuestro laboratorio desde 1997. En comparación con la cepa RHA-I, la cepa RLA-I muestra incrementos en las respuestas hormonales al estrés, así como en conductas de ansiedad/miedo en una variedad de pruebas y variables conductuales incondicionadas. Hasta la fecha, las cepas de ratas Romanas no han sido comparadas en procedimientos de condicionamiento clásico de miedo a contextos o estímulos discretos. El presente trabajo tuvo como objetivo comparar ambas en 1) dos procedimientos de medida de la respuesta de sobresalto potenciada por miedo; y, 2) en un procedimiento de condicionamiento clásico de miedo (petrificación condicionada). Los resultados indican que las ratas RLA-I muestran niveles mayores de condicionamiento de miedo (respuesta de sobresalto y respuesta de petrificación) que las RHA-I, reforzando así los perfiles diferenciales de ansiedad/miedo de las dos cepas.

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    • "Similar results (more behavioral inhibition in RLA rats vs. RHA rats) are found when the animals are exposed to anxiogenic situations related to novelty and exploration, such as the open field, the hole board, and the light/dark box (e.g., Fernández-Teruel et al., 1992; Fernández-Teruel, Escorihuela, Castellano, González, & Tobeña, 1997; Manzo, Gómez, Callejas-Aguilera, Donaire et al., 2014). In addition, RLA rats show higher rates of unconditioned and conditioned fear responses (e.g., defecation, freezing, grooming, startle response, and passive avoidance) than RHA rats (Escorihuela et al., 1999; López-Aumatell et al., 2009). However, there are contradictory results when using other tests of anxiety, such as the elevated plus-maze, the successive alley, and the mobility test, given that the expected greater tendency of RHA rats to explore open and novel spaces is not always observed (Donaire, Sabariego, Cano et al., 2013, unpublished results; Escorihuela et al., 1999). "

    Full-text · Article · Aug 2014 · Journal of Comparative Psychology
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    • "This hypothesis is not incompatible with previous data, and two different kinds of evidence could indirectly support it, First, in the inbred Roman rat (i.e. RHA-I and RLA-I) strains, which have been psychogeneticallyselected for their extreme responses in anxiety-related tasks, the low anxious (and high impulsive) RHA-I strain do not show fear-induced potentiation of startle in a typical cue-conditioning procedure, while the relatively high anxious (and low impulsive) RLA-I strain show clear fear-potentiated startle responses [12]. Second, some seminal conditioning studies in psychopaths using single cue paradigms and electrodermal activity showed less conditioning in these subjects compared with control participants [16] [17], and recent studies have also shown that psychopathic and antisocial individuals do not show increased skin conductance responses to CS+ stimuli in differential conditioning paradigms [18] [19]. "

    Full-text · Article · Jan 2013 · Open Journal of Psychiatry
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    • "RLA < RHA and RLA-I < RHA-I [11] [13] [41] EPHX2 * Saccharin preference RLA < RHA [16] [37] EPHX2 * Stress-induced prolactin response RLA > RHA RLA-I > RHA-I [18,41,42] [7] [9] PRL * Passive coping responses (e.g. self-grooming, freezing) under exposure to novelty RLA-I > RHA-I RLA > RHA and RLA-I > RHA-I [13] [41] CAMKK2 * Classical fear conditioning (freezing) and fear-potentiated startle RLA-I > RHA-I [28] [49] CAMMK2 * Stress-induced RLA > RHA [2] [7] [18] [41] [42] [46] CRHBP (CRH-dependent) HPA-axis hormonal responses RLA-I > RHA-I [6] [9] [11] * CRH receptors in hypothalamus and BNST RLA-I > RHA-I [6] CRHBP * Novelty-seeking behavior RHA > RLA RHA-I > RLA-I [16] [13] HOMER3 * Ethanol and cocaine-seeking behavior RHA > RLA [15] [16] [19] [37] HOMER3 * Impulsivity behavior and attention deficits RHA-I > RLA-I [33] "
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    ABSTRACT: Microarray technology was used to explore differences in brain gene expression under basal conditions in two strains of psychogenetically selected rats which differ in anxiety/stress responses, the inbred Roman High-(RHA-I) and Roman Low-(RLA-I) Avoidance rats. Microarray analysis detected 14 up-regulated and 24 down-regulated genes in RLA-I vs. RHA-I rats functionally related to neurobiological processes. The differentially expressed genes CAMKK2, CRHBP, EPHX2, HOMER3, NDN, PRL and RPL6 were selected for microarray validation using qRT-PCR. EPHX2, CAMKK2 (both up-regulated in RLA-I vs. RHA-I rats) and HOMER3 (down-regulated in RLA-I vs. RHA-I rats) showed a similar tendency and fold-change both in microarray and RT-PCR analyses; PRL (up-regulated in RLA-I vs. RHA-I rats), CRHBP and RPL6 (both down-regulated in RLA-I vs. RHA-I animals) showed a similar tendency but a different order of magnitude of change among experiments; finally, NDN was validated neither in tendency nor in magnitude of change.
    Full-text · Article · Sep 2011 · Neuroscience Letters
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