Person:
Gruart, Agnès

Catedrático/a de Universidad
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First Name
Agnès
Last Name
Gruart
Affiliation
Universidad Pablo de Olavide
Department
Fisiología, Anatomía y Biología Celular
Research Center
Area
Fisiología
Research Group
Laboratorio de Neurociencias
PAIDI Areas
Biología y Biotecnología
PhD programs
Papel de las estructuras corticales (prefrontal, premotora, motora, hipocampal), subcorticales (estriado, amígdala, núcleo rojo, centros motores troncoencefálicos) y cerebelares en la adquisición de tareas de aprendizaje asociativo, Mecanismos Cerebrales Subyacentes a los Procesos de Memoria y su Deterioro
Identifiers
UPO investigaORCIDScopus Author IDDialnet IDGoogle Scholar ID

Search Results

Now showing 1 - 10 of 19
  • Publication
    Ciencia Internacional en la UPO
    (2018) Aram, Bethany; Marchena Fernández, Juan; Gutiérrez Montoya, Nayibe; Gruart, Agnès; Delgado-García, José María; Gómez Skarmeta, José Luis; Merino, Luis; Navas, Fátima; Escribano Páez, José Miguel; Pérez-García, Manuel; Monreal-Gimeno, M Carmen; Artal-Sanz, Marta; Muñoz Ruiz, Manuel Jesús; Moral Martos, Francisco; Málvarez, Gonzalo; Márquez-Ruiz, Javier; Martínez-Álvarez, Francisco; Calero, Sofia 
    La Biblioteca/CRAI acogió desde el 26 de febrero al 7 de marzo de 2018 la exposición "Ciencia Internacional en la UPO" organizada por el Vicerrectorado de Investigación y Transferencia de Tecnología de la Universidad y que pretende mostrar la investigación de excelencia que se desarrolla en la Olavide en el marco de Programas Internacionales de I+D+i. La muestra estaba constituida por una selección de proyectos internacionales de investigación liderados por la UPO o con participación relevante de sus investigadores/as, de distintas temáticas como la Historia, la Biología, la Ciencia de Materiales, las Neurociencias, los Estudios de Género, la Robótica o el Clima.
  • Publication
    A cognitive-related neural oscillation pattern, generated in the prelimbic cortex, can control operant learning in rats
    (2016) Hernández-González, Samuel; Gruart, Agnès; Delgado-García, José María; Andreu-Sánchez, Celia; Martín-Pascual, Miguel Ángel
  • Publication
    TIMING AND CAUSALITY IN THE GENERATION OF LEARNED EYELID RESPONSES
    (Frontiers Media, 2011-08-30) Sánchez-Campusano, Raudel; Gruart, Agnès
    The cerebellum-red nucleus-facial motoneuron (Mn) pathway has been reported as being involved in the proper timing of classically conditioned eyelid responses. This special type of associative learning serves as a model of event timing for studying the role of the cerebellum in dynamic motor control. Here, we have re-analyzed the firing activities of cerebellar posterior interpositus (IP) neurons and orbicularis oculi (OO) Mns in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. The aim was to revisit the hypothesis that the IP neurons can be considered a neuronal phase-modulating device supporting OO Mns firing with an emergent timing mechanism and an explicit correlation code during learned eyelid movements. Optimized experimental and computational tools allowed us to determine the different causal relationships (temporal order and correlation code) during and between trials. These intra- and inter-trial timing strategies expanding from sub-second range (millisecond timing) to longer-lasting ranges (interval timing) expanded the functional domain of cerebellar timing beyond motor control. Interestingly, the results supported the above-mentioned hypothesis. The causal inferences were influenced by the precise motor and premotor spike-timing in the cause-effect interval, and, in addition, the timing of the learned responses depended on cerebellar-Mn network causality. Furthermore, the timing of CRs depended upon the probability of simulated causal conditions in the cause-effect interval and not the mere duration of the inter-stimulus interval. In this work, the close relation between timing and causality was verified. It could thus be concluded that the firing activities of IP neurons may be related more to the proper performance of ongoing CRs (i.e., the proper timing as a consequence of the pertinent causality) than to their generation and/or initiation. *Raudel Sánchez-Campusano. Corresponding Author. Email: rsancam@upo.es
  • Publication
    PRESYNAPTIC GABAB RECEPTORS REGULATE HIPPOCAMPAL SYNAPSES DURING ASSOCIATIVE LEARNING IN BEHAVING MICE
    (Public Library of Science, 2016-02-05) M.T. Jurado-Parras, J.M. Delgado-García, R. Sánchez-Campusano, M. Gassmann, B. Bettler, A. Gruart; Sánchez-Campusano, Raudel; Gruart, Agnès
    GABAB receptors are the G-protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the central nervous system. Pharmacological activation of GABAB receptors regulates neurotransmission and neuronal excitability at pre- and postsynaptic sites. Electrophysiological activation of GABAB receptors in brain slices generally requires strong stimulus intensities. This raises the question as to whether behavioral stimuli are strong enough to activate GABAB receptors. Here we show that GABAB1a -/- mice, which constitutively lack presynaptic GABAB receptors at glutamatergic synapses, are impaired in their ability to acquire an operant learning task. In vivo recordings during the operant conditioning reveal a deficit in learning-dependent increases in synaptic strength at CA3-CA1 synapses. Moreover, GABAB1a -/- mice fail to synchronize neuronal activity in the CA1 area during the acquisition process. Our results support that activation of presynaptic hippocampal GABAB receptors is important for acquisition of a learning task and for learning-associated synaptic changes and network dynamics.
  • Publication
    THE EPIGENETIC FACTOR CBP IS REQUIRED FOR THE DIFFERENTIATION AND FUNCTION OF MEDIAL GANGLIONIC EMINENCE-DERIVED INTERNEURONS
    (Springer Nature, 2019-06) A. Medrano-Fernández, J.M. Delgado-García, B. Del-Blanco, M. Llinares, R. Sánchez-Campusano, R. Olivares, A. Gruart, A. Barco; Sánchez-Campusano, Raudel; Gruart, Agnès
    The development of inhibitory circuits depends on the action of a network of transcription factors and epigenetic regulators that are critical for interneuron specification and differentiation. Although the identity of many of these transcription factors is well established, much less is known about the specific contribution of the chromatin-modifying enzymes that sculpt the interneuron epigenome. Here, we generated a mouse model in which the lysine acetyltransferase CBP is specifically removed from neural progenitors at the median ganglionic eminence (MGE), the structure where the most abundant types of cortical interneurons are born. Ablation of CBP interfered with the development of MGE-derived interneurons in both sexes, causing a reduction in the number of functionally mature interneurons in the adult forebrain. Genetic fate mapping experiments not only demonstrated that CBP ablation impacts on different interneuron classes, but also unveiled a compensatory increment of interneurons that escaped recombination and cushion the excitatory-inhibitory imbalance. Consistent with having a reduced number of interneurons, CBPdeficient mice exhibited a high incidence of spontaneous epileptic seizures, and alterations in brain rhythms and enhanced low gamma activity during status epilepticus. These perturbations led to abnormal behavior including hyperlocomotion, increased anxiety and cognitive impairments. Overall, our study demonstrates that CBP is essential for interneuron development and the proper functioning of inhibitory circuitry in vivo.
  • Publication
    TRANSCRANIAL DIRECT-CURRENT STIMULATION MODULATES SYNAPTIC MECHANISMS INVOLVED IN ASSOCIATIVE LEARNING IN BEHAVING RABBITS
    (Proceedings of the National Academy of Sciences of the United States of America, 2012-04-24) J. Márquez-Ruiz, R. Leal-Campanario, R. Sánchez-Campusano, B. Molaee-Ardekani, F. Wendling, P.C. Miranda, G. Ruffini, A. Gruart, and J.M. Delgado-García; Leal Campanario, Rocío; Sánchez-Campusano, Raudel; Gruart, Agnès
    Transcranial direct-current stimulation (tDCS) is a noninvasive brain stimulation technique that has been successfully applied for modulation of cortical excitability. tDCS is capable of inducing changes in neuronal membrane potentials in a polarity-dependent manner. When tDCS is of sufficient length, synaptically driven aftereffects are induced. The mechanisms underlying these after-effects are largely unknown, and there is a compelling need for animal models to test the immediate effects and after-effects induced by tDCS in different cortical areas and evaluate the implications in complex cerebral processes. Here we show in behaving rabbits that tDCS applied over the somatosensory cortex modulates cortical processes consequent to localized stimulation of the whisker pad or of the corresponding area of the ventroposterior medial (VPM) thalamic nucleus. With longer stimulation periods, poststimulation effects were observed in the somatosensory cortex only after cathodal tDCS. Consistent with the polarity-specific effects, the acquisition of classical eyeblink conditioning was potentiated or depressed by the simultaneous application of anodal or cathodal tDCS, respectively, when stimulation of the whisker pad was used as conditioned stimulus, suggesting that tDCS modulates the sensory perception process necessary for associative learning. We also studied the putative mechanisms underlying immediate effects and after-effects of tDCS observed in the somatosensory cortex. Results when pairs of pulses applied to the thalamic VPM nucleus (mediating sensory input) during anodal and cathodal tDCS suggest that tDCS modifies thalamocortical synapses at presynaptic sites. Finally, we show that blocking the activation of adenosine A1 receptors prevents the long-term depression (LTD) evoked in the somatosensory cortex after cathodal tDCS.
  • Publication
    THE ACTIVITY OF THE PRELIMBIC CORTEX IN RATS IS ENHANCED DURING THE COOPERATIVE ACQUISITION OF AN INSTRUMENTAL LEARNING TASK
    (Elsevier Ltd, 2019-09-12) A.R. Conde-Moro, F. Rocha-Almeida, R. Sánchez-Campusano, J.M. Delgado-García, A. Gruart; Sánchez-Campusano, Raudel; Gruart, Agnès
    The objective of this study was to identify the functional properties of the prefrontal cortex that allow animals to work together to obtain a mutual reward. We induced pairs of male rats to develop a cooperative behavior in two adjacent Skinner boxes divided by a metallic grille. The experimental boxes allowed the two rats to see and to smell each other and to have limited physical contact through the grille. Rats were progressively trained to climb onto two separate platforms (and stay there simultaneously for>0.5 s) to get food pellets for both. This set-up was compatible with the in vivo recording of local field potentials (LFPs) at the prelimbic (PrL) cortex throughout the task. A dominant delta/theta activity appeared mostly during the period in which rats were located on the platforms. Spectral powers were larger when rats had to stay together on the platforms than when they jumped individually onto them. When paired together, rats presented significant differences in the power of delta and low theta bands depending if they were leading or following the joint activity. PrL cortex encodes neural commands related to the individual and joint acquisition of an operant conditioning task by behaving rats.
  • Publication
    THE CLAUSTRUM IS INVOLVED IN COGNITIVE PROCESSES RELATED TO THE CLASSICAL CONDITIONING OF EYELID RESPONSES IN BEHAVING RABBITS
    (Oxford University Press, 2021-01) M. Mar Reus-García, R. Sánchez-Campusano, J. Ledderose, G.K. Dogbevia, M. Treviño, M.T. Hasan, A. Gruart, J.M. Delgado-García; Sánchez-Campusano, Raudel; Gruart, Agnès
    It is assumed that the claustrum (CL) is involved in sensorimotor integration and cognitive processes.We recorded the firing activity of identified CL neurons during classical eyeblink conditioning in rabbits, using a delay paradigm in which a tone was presented as conditioned stimulus (CS), followed by a corneal air puff as unconditioned stimulus (US). Neurons were identified by their activation from motor (MC), cingulate (CC), and medial prefrontal (mPFC) cortices. CL neurons were rarely activated by single stimuli of any modality. In contrast, their firing was significantly modulated during the first sessions of paired CS/US presentations, but not in well-trained animals. Neuron firing rates did not correlate with the kinematics of conditioned responses (CRs). CL local field potentials (LFPs) changed their spectral power across learning and presented well-differentiated CL–mPFC/CL–MC network dynamics, as shown by crossfrequency spectral measurements. CL electrical stimulation did not evoke eyelid responses, even in trained animals. Silencing of synaptic transmission of CL neurons by the vINSIST method delayed the acquisition of CRs but did not affect their presentation rate. The CL plays an important role in the acquisition of associative learning,mostly in relation to the novelty of CS/US association, but not in the expression of CRs.
  • Publication
    THE CEREBELLAR INTERPOSITUS NUCLEUS AND THE DYNAMIC CONTROL OF LEARNED MOTOR RESPONSES
    (Society for Neuroscience, 2007-06-20) R. Sánchez-Campusano, A. Gruart, and J.M. Delgado-García; Sánchez-Campusano, Raudel; Gruart, Agnès
    The role played by the cerebellum in movement control requires knowledge of interdependent relationships between kinetic neural commands and the performance (kinematics) of learned motor responses. The eyelid motor system is an excellent model for studying how simple motor responses are elaborated and performed. Kinetic variables (n 24) were determined here by recording the firing activities of orbicularis oculi motoneurons and cerebellar interpositus neurons in alert cats during classical conditioning, using a delay paradigm. Kinematic variables (n 36) were selected from eyelid position, velocity, and acceleration traces recorded during the conditioned stimulus– unconditioned stimulus interval. Optimized experimental and analytical tools allowed us to determine the evolution of kinetic and kinematic variables, the dynamic correlation functions relating motoneuron and interpositus neuron firing to eyelid conditioning responses, the falling correlation property of the interpositus nucleus across the successive training sessions, the time and significance of the linear relationships between these variables, and finally, the phase-inversion property of interpositus neurons with respect to acquired conditioned responses. Whereas motoneurons encoded eyelid kinematics at every instant of the dynamic correlation range and generated the natural oscillatory properties of the neuromuscular elements involved in eyeblinks, interpositus neurons did not directly encode eyelid performance: namely, their contribution was only slightly significant in the dynamic correlation range, and this regularity caused the integrated neuronal activity to oscillate by progressively inverting phase information. Therefore, interpositus neurons seem to play a modulating role in the dynamic control of learned motor responses, i.e., they could be considered a neuronal phase-modulating device.
  • Publication
    A Differential and Timed Contribution of Identified Hippocampal Synapses to Associative Learning in Mice
    (Oxford University Press, 2015-09) Gruart, Agnès; Sánchez-Campusano, Raudel; Fernández-Guizán, A.; Delgado-García, J.M.
    Although it is generally assumed that the hippocampus is involved in associative learning, the specific contribution of the different synapses present in its intrinsic circuit or comprising its afferents and efferents is poorly defined. We studied here activity-dependent changes in synaptic strength of 9 hippocampal synapses (corresponding to the intrinsic hippocampal circuitry and to its main inputs and outputs) during the acquisition of a trace eyeblink conditioning in behaving mice. The timing and intensity of synaptic changes across the acquisition process was determined. The evolution of these timed changes in synaptic strength indicated that their functional organization did not coincide with their sequential distribution according to anatomical criteria and connectivity. Furthermore, we explored the functional relevance of the extrinsic and intrinsic afferents to CA3 and CA1 pyramidal neurons, and evaluated the distinct input patterns to the intrinsic hippocampal circuit. Results confirm that the acquisition of a classical eyeblink conditioning is a multisynaptic process in which the contribution of each synaptic contact is different in strength, and takes place at different moments across learning. Thus, the precise and timed activation of multiple hippocampal synaptic contacts during classical eyeblink conditioning evokes a specific, dynamic map of functional synaptic states in that circuit.