Prepulse inhibition modulation by contextual conditioning of dopaminergic activity

When a neutral stimulus is repeatedly paired with a drug, an association is established between them that can induce two different responses: either an opponent response that counteracts the effect of the drug, or a response thatis similar to thatinduced by the drug. In this paper, we focus on the analysis ofthe associations that can be established between the contextual cues and the administration of dopamine agonists or antagonists. Our hypothesis suggests that repeated administration of drugs that modulate dopaminergic activity in the presence of a specific context leads to the establishment of an association that subsequently results in a conditioned response to the context that is similar to that induced by the drug. To test this hypothesis, we conducted two experiments that revealed that contextual cues acquired the property to modulate pre-pulse inhibition by prior pairings of such context with the dopamine antagonist haloperidol (Experiment 1), and with the dopamine agonist d-amphetamine (Experiment 2). The implications of these results are discussed both at a theoretical level, and attending to the possibilities that could involve the use of context cues for the therapeutic administration of dopaminergic drugs.Junta de Andalucía SEJ-02618Ministerio de Ciencia e Innovación de España PSI2012-3207

Food and water deprivation disrupts latent inhibition with an auditory fear conditioning procedure

Latent inhibition (LI), operationally defined as the reduced conditioned response to a stimulus that has been preexposed before conditioning, seems to be determined by the interaction of different processes that includes attentional, associative, memory, motivational, and emotional factors. In this paper we focused on the role of deprivation level on LI intensity using an auditory fear conditioning procedure with rats. LI was observed when the animals were non-deprived, but it was disrupted when the rats were water- or food-deprived. We propose that deprivation induced an increase in attention to the tobe-CS, and, as a result, LI was disrupted in deprived animals. The implications ofthe results for the current interpretations of LI are also discussed.Ministerio de Economía y Competitividad de España PSI2012-3207

Contextual control of flavor neophobia

The role of context in the retrieval of learned information has been widely analyzed in the associative learning domain. However, evidence about the effect of context on flavor memory retrieval is more limited. We have carried out four experiments with rats testing for possible interactions between neophobia habituation and the context in which flavors are presented, by manipulating prior experience with contexts. Our results point to the relevance of context familiarity for the establishment and recovery of a safe taste memory trace. More specifically, the use of the animals' home cages as experimental context favored neophobia habituation (Experiments 1A and 2), reduced dopamine levels induced by administration of the dopamine D1-like receptor antagonist SCH-23390 disrupted neophobia habituation when tested in presence of a new context (Experiment 1B), and testing in the animal's home cage increases the amount of flavor consumed, even when such flavor had a previous history of aversive conditioning (Experiment 3). We propose that exploring context without aversive consequences generates a safe memory trace of such context that becomes in the basis of increased flavor consumption

Temporal factors modulate haloperidol-induced conditioned catalepsy

Repeated pairings of a neutral context and the effects of haloperidol give rise to conditioned catalepsy when the context is subsequently presented in a drug-free test. In order to confirm whether this response is based on Pavlovian processes, we conducted two experiments involving two manipulations that affect conditioning intensity in classical conditioning procedures: time of joint exposure to the conditioned and the unconditioned stimulus, and the length of the inter-stimulus interval (ISI). The results revealed that both an increase in the length of context-drug pairings during conditioning and a reduced ISI between drug administration and context exposure increased conditioned catalepsy. These results are discussed in terms of the temporal peculiarities of those procedures that involve drugs as the unconditioned stimulus along with the role of Pavlovian conditioning in context-dependent catalepsy.Agencia Estatal de Investigación PID2019-103982RBC42/AEI/10.13039/50110001103

Especificidad contextual de la inhibición latente en palomas (Columba livia): Atenuación del efecto de retraso en contextos familiares

En el presente artículo se describe un experimento, llevado a cabo con palomas (Columba livia) y con un procedimiento de supresión condicionada, diseñado para determinar si la atenuación de la Inhibición Latente, tras un cambio contextual entre las fases de pre-exposición y de prueba, se debe a un proceso de inhibición externa, tal y como propone la Teoría de la Atención Condicionada (Lubow y cols. 1981), o al establecimiento de una asociación en el almacén de memoria a largo plazo de los sujetos entre las claves contextuales en las que tiene lugar la pre-exposición y el estímulo pre-expuesto (Wagner, 1976, 1978). Pretendemos comprobar, de esta forma, si es el cambio contextual en sí mismo, el responsable de la atenuación de la Inhibición Latente. Los resultados muestran que, aparte de conseguir la generalización del fenómeno que nos ocupa a las palomas, es probablemente el cambio contextual en sí mismo el causante de la atenuación de la Inhibición Latente

Startle response and prepulse inhibition modulation by positive- and negative-induced affect

The startle response, a set of reflex behaviours intended to prepare the organism to face a potentially threatening stimulus, can be modulated by several factors as, for example, changes in affective state, or previous presentation of a weak stimulus (a phenomenon termed Pre-Pulse Inhibition [PPI]). In this paper we analyse whether the induction of positive or negative affective states in the participants modulates the startle response and the PPI phenomenon. The results revealed a decrease of the startle response and an increase of the PPI effect when registered while the participants were exposed to pleasant images (Experiment 1), and an increase of the startle response and of the PPI effect when they were exposed to a video-clip of unpleasant content (Experiment 2). These data are interpreted considering that changes in affective states correlate with changes in the startle reflex intensity, but changes in PPI might be the result of an attentional processMinisterio de Economía y Competitividad de España PSI2012-32077Junta de Andalucía SEJ-0261

Efecto de un intervalo de retención entre la pre-exposición y el condicionamiento sobre la inhibición latente en humanos con un procedimiento de condicionamiento palpebral

El fenómeno de la inhibición latente se refiere al retraso que se observa cuando se presenta repetidamente sin consecuencias un estímulo que va a ser posteriormente condicionado. En este trabajo empleamos un procedimiento de condicionamiento palpebral para analizar la inhibición latente en participantes humanos. El Experimento 1 reveló que el procedimiento empleado era adecuado para reproducir el efecto de inhibición latente. En el Experimento 2, la introducción de un intervalo de tres minutos entre las fases de pre-exposición y condicionamiento dio lugar a la atenuación de la inhibición latente. Estos resultados contribuyen a la identificación de los mecanismos que participan en la pre-exposición y posterior condicionamiento de un estímulo, aspectos particularmente importantes si tenemos en cuenta que el fenómeno de la inhibición latente ha sido utilizado repetidamente como un instrumento para analizar el curso del proceso atencional tanto en poblaciones normales como con determinadas psicopatologías.Latent inhibition, retarded learning after pre-exposure to the to-be-conditioned stimulus, was examined using a blink conditioned procedure in humans. Experiment 1 showed that the procedure is suited to inducing the latent inhibition effect. In Experiment 2, the introduction of a 3-minute interval between pre-exposure and conditioning phases attenuated latent inhibition. These results contribute to identify the mechanisms involved in pre-exposure and subsequent conditioning of a stimulus, which is particularly important if we bear in mind that latent inhibition has been used repeatedly as an instrument to analyse the course of attentional processes in normal and pathological populations

Interrupción del efecto de inhibición latente por la administración de Mk-801

Los receptores -metil-D-aspartato (NMDA) parecen estar implicados en el retraso en la adquisición de una asociación pavloviana tras la preexposición sin consecuencias al que se va a convertir en estímulo condicionado, efecto al que se suele denominar Inhibición Latente (IL). Concretamente, la administración de compuestos antagonistas en la fase de preexposición o en las fases de preexposición y condicionamiento produce un efecto disruptivo sobre la expresión de la IL cuando se utiliza un procedimiento de aversión condicionada al sabor. En este trabajo describimos tres experimentos que replican el efecto del MK-801 sobre la IL (Experimento 1) y que demuestran la persistencia de la influencia de la droga independientemente del número de ensayos de preexposición (Experimento 2), o de la intensidad del EC empleado (Experimento 3). Los resultados se interpretan en relación a los modelos psicológicos y farmacológicos relacionados con la investigación y el tratamiento clínico de diversos desordenes neurocognitivos

En torno a la tesis doctoral de Edward Lee Thorndike

La obra científica de Thorndike se desarrolla durante un período de grandes cambios institucionales y profesionales en la psicología norteamericana. En el seno de estos cambios, la obra de este autor sobresale como uno de los referentes más claros, permanentes y respetados. Probablemente, ello se deba a que en su trabajo destacan como características más básicas el uso de métodos experimentales, la simplicidad conceptual, el rigor y la consistencia interna. Rasgos que se encuentran ya en su tesis doctoral, una de las pocas que se han convertido en un clásico.Thorndike’ scientific works developed within an epoch in which North American Psychology underwent deep institutional and professional changes. During those changes, his work was one of the most enduring, respected and clearer standard. Probably, as a result of its main features: experimental methods, conceptual simplicity, meticulousness and internal consistency. All these features can be found in his thesis, one of the few one that has become a classic.Dirección General de Investigación Científica y Técnica PB95-0529-C0