8 research outputs found
Psychopharmacology of memory and emotion in humans
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, Departamento de Psicología Básica I (Procesos Cognitivos), leída el 16-06-2017El principal propósito de esta tesis ha sido ahondar en el conocimiento del mecanismo neural subyacente a la influencia de la emoción y el sistema motor en la memoria. El primero de los estudios presentados incide sobre la posibilidad de disminuir la memoria episódica, mientras que el segundo estudio presentado incide sobre la viabilidad de aumentarla. En el primer capítulo, se resumen las principales teorías sobre los procesos de memoria, desde las teorías clásicas a las más actuales. El segundo capítulo repasa los principales sistemas de neurotransmisores del sistema nervioso central y su relación con la emoción y la memoria, presentando los principales estudios en humanos o en animales. En el tercer y cuarto capítulos, se presentan dos estudios novedosos, que son una réplica y ampliación de dos estudios previos. Las teorías clásicas han considerado la memoria como una facultad monolítica e inmutable de la mente. Sin embargo, las nuevas actualizaciones provenientes de las investigaciones realizadas en las últimas décadas, abren una puerta a la modificación de memorias previamente consolidadas. La teoría de la reconsolidación establece la posibilidad de reactivar de nuevo una memoria mediante la presentación de una “clave” relacionada con la misma. Una vez la memoria es reactivada es susceptible de ser modificada dentro de una ventana de tiempo, mediante la administración de diferentes tipos de manipulaciones, tanto de carácter conductual como farmacológico; necesitando ser consolidada de nuevo después de la reactivación. La reconsolidación de la memoria ha sido observada en diferentes especies animales y en humanos, así como con diferentes tareas y tipos de memoria...The main objective of this thesis has been to deepen the knowledge of the neural mechanism underlying the influence of emotion as well as the motor system in memory. The first of the studies presented focuses on the possibility of decreasing episodic memory, while the second study refers to the feasibility of increasing it. In the first chapter, the main theories about the processes of memory are summarized, from the classic theories to the more actual ones. The second chapter reviews the main neurotransmitter systems of the central nervous system and its relation to emotion and memory, presenting the main studies in humans or animals. In the third and fourth chapters, two novel studies are presented, which are a replication and extension of two previous studies. Classical theories have considered memory as a monolithic and immutable faculty of mind. However, new updates from the research carried out in the last decades, opens a door to the modification of previously consolidated memories. The theory of reconsolidation postulates that upon reactivation, memories can become labile and susceptible to manipulation, requiring a new restabilization process in order to maintain them. The reconsolidation of memory has been observed in different animal species and in humans, as well as with different tasks and types of memory. The first study presented (Chapter 3) is based on the hypothesis of the implication of the GABAergic system in the deterioration of the reconsolidation of an episodic emotional memory. For the accomplishment of this experiment it was counted on the participation of patients who were going to undergo an endoscopy procedure and therefore, to receive a scheduled sedation. The results show the impairment of the emotional memory by the administration of propofol, an anesthetic agent, immediately after the reactivation. A significant proportion of the population is affected by psychiatric disorders that have at their core a traumatic or maladaptive emotional memory. The possibility of modifying this type of memory opens a range to new treatments and adjuvant therapies to those already existing...Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEunpu
Bidirectional synaptic plasticity can explain bidirectional retrograde effects of emotion on memory
Emotional events can cither impair or enhance memory for
immediately preceding items, '["he GANK model explains this bidirectional effect as a glulamale "priority" signal that modulates nor adrenaline release depending on arousal state. We argue for an alternative explanation: that priority itself evokes phasic nor adrenaline release. Thus, contrasting K-l memory effects are explained by a
mechanism based on the Bienensloek-Cooper—Munro theory
Action boosts episodic memory encoding in humans via engagement of a noradrenergic system
We are constantly interacting with our environment whilst we encode memories. However, how actions influence memory formation remains poorly understood. Goal-directed movement engages the locus coeruleus (LC), the main source of noradrenaline in the brain. Noradrenaline is also known to enhance episodic encoding, suggesting that action could improve memory via LC engagement. Here we demonstrate, across seven experiments, that action (Go-response) enhances episodic encoding for stimuli unrelated to the action itself, compared to action inhibition (NoGo). Functional magnetic resonance imaging, and pupil diameter as a proxy measure for LC-noradrenaline transmission, indicate increased encodingrelated LC activity during action. A final experiment, replicated in two independent samples, confirmed a novel prediction derived from these data that emotionally aversive stimuli, which recruit the noradrenergic system, modulate the mnemonic advantage conferred by Go-responses relative to neutral stimuli. We therefore provide converging evidence that action boosts episodic memory encoding via a noradrenergic mechanism
Bidirectional synaptic plasticity can explain bidirectional retrograde effects of emotion on memory
Nucleus Accumbens Stimulation Modulates Inhibitory Control by Right Prefrontal Cortex Activation in Obsessive-Compulsive Disorder
Inhibitory control is considered a compromised cognitive function in obsessive-compulsive (OCD) patients and likely linked to corticostriatal circuitry disturbances. Here, 9 refractory OCD patients treated with deep brain stimulation (DBS) were evaluated to address the dynamic modulations of large-scale cortical network activity involved in inhibitory control after nucleus accumbens (NAc) stimulation and their relationship with cortical thickness. A comparison of DBS "On/Off" states showed that patients committed fewer errors and exhibited increased intraindividual reaction time variability, resulting in improved goal maintenance abilities and proactive inhibitory control. Visual P3 event-related potentials showed increased amplitudes during Go/NoGo performance. Go and NoGo responses increased cortical activation mainly over the right inferior frontal gyrus and medial frontal gyrus, respectively. Moreover, increased cortical activation in these areas was equally associated with a higher cortical thickness within the prefrontal cortex. These results highlight the critical role of NAc DBS for preferentially modulating the neuronal activity underlying sustained speed responses and inhibitory control in OCD patients and show that it is triggered by reorganizing brain functions to the right prefrontal regions, which may depend on the underlying cortical thinning. Our findings provide updated structural and functional evidence that supports critical dopaminergic-mediated frontal-striatal network interactions in OCD.31(5):2742-2758.
doi: 10.1093/cercor/bhaa39