Person: Perezzan, Ramiro
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Ramiro
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Perezzan
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Ciencias Experimentales
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Item Time Series Analysis Applied to EEG Shows Increased Global Connectivity during Motor Activation Detected in PD Patients Compared to Controls.(Applied Sciences, 2020) Maitín, Ana María; Perezzan, Ramiro; Herráez Aguilar, Diego; Serrano, José Ignacio; Del Castillo, María Dolores; Arroyo, Aída; Andreo, Jorge; Romero Muñoz, Juan PabloBackground: Brain connectivity has shown to be a key characteristic in the study of both Parkinson’s Disease (PD) and the response of the patients to the dopaminergic medication. Time series analysis has been used here for the first time to study brain connectivity changes during motor activation in PD. Methods: A 64-channel EEG signal was registered during unilateral motor activation and resting-state in 6 non-demented PD patients before and after the administration of levodopa and in 6 matched healthy controls. Spectral entropy correlation, coherence, and interhemispheric divergence differences among PD patients and controls were analyzed under the assumption of stationarity of the time series. Results: During the motor activation test, PD patients showed an increased correlation coefficient (both hands p < 0.001) and a remarkable increase in coherence in all frequency range compared to the generalized reduction observed in controls (both hands p < 0.001). The Kullback–Leibler Divergence (KLD) of the Spectral Entropy between brain hemispheres was observed to increase in controls (right hand p = 0.01; left hand p = 0.015) and to decrease in PD patients (right hand p = 0.02; left hand p = 0.002) with motor activation. Conclusions: Our results suggest that the oscillatory activity of the different cortex areas within healthy brains is relatively independent of the rest. PD brains exhibit a stronger connectivity which grows during motor activation. The levodopa mitigates this anomalous performance.Item Adolescent exposure to the Spice/K2 cannabinoid JWH-018 impairs sensorimotor gating and alters cortical perineuronal nets in a sex-dependent manner.(Translational Psychiatry, 2023) Izquierdo Luengo, Cristina; Ten Blanco, Marc; Ponce Renilla, María; Perezzan, Ramiro; Pereda Pérez, Inmaculada; Berrendero, FernandoThe consumption of synthetic cannabinoids during adolescence is reported to be a risk factor for the appearance of psychiatric disorders later in life. JWH-018 was identified as one of the primary psychoactive components present in Spice/K2 preparations. This study evaluated the short- and long-term consequences of exposure to JWH-018 during the adolescence in anxiety-like behavior, fear extinction, and sensorimotor gating in male and female mice. Alterations in anxiety varied depending on the time interval between treatment and behavioral analysis along with sex, while no changes were observed in the extinction of fear memory. A decrease in prepulse inhibition of the startle reflex was revealed in male, but not female, mice at short- and long-term. This behavioral disturbance was associated with a reduction in the number of perineuronal nets in the prelimbic and infralimbic regions of the prefrontal cortex in the short-term. Furthermore, adolescent exposure to JWH-018 induced an activation of microglia and astrocytes in the prefrontal cortex of male mice at both time intervals. A transitory decrease in the expression of GAD67 and CB2 cannabinoid receptors in the prefrontal cortex was also found in male mice exposed to JWH-018. These data reveal that the treatment with JWH-018 during the adolescence leads to long-lasting neurobiological changes related to psychotic-like symptoms, which were sex-dependent.Item Seminarios como herramienta para el encuentro eficiente entre profesor y alumno en asignaturas de Química del Grado de Farmacia.(Octaedro, 2023) Perezzan, Ramiro; Herráez Aguilar, Diego; Montalvo Quiros, SandraItem Chlorination and Solvothermal Treatment of Zr(C5H5)2Cl2: a Synthetic Combination to Produce Nanometric Tetragonal ZrO2.(Inorganic Chemistry, 2011) Ávila Brande, D.; Perezzan, Ramiro; Urones Garrote, E.; Otero Díaz, L.C.A novel synthetic strategy based on the combination of the chlorination of an organometallic precursor followed by solvothermal treatment is found to be successful in the synthesis of tetragonal nano-ZrO2 or nano-ZrO2, embedded in an amorphous carbon matrix, depending on the solvent employed in the solvothermal step. The chemical and structural features (chemical composition, size and surface defects) of the intermediate and final materials have been determined experimentally mainly by high resolution transmission electron microscopy, electron energy loss spectroscopy, and Z-contrast images. These local techniques reveal that the nanoparticles consist of tetragonal ZrO2 with an average size of 1.7 ± 0.4 and 6.2 ± 0.9 nm for the embedded in carbon and the free nano-ZrO2, respectively.Item Electron Microscopy Characterization of Nanometric ZrO2 and Er2O2S Synthetized from Organometallic Precursors.(Microscopy and Microanalysis, 2012) Ávila Brande, D.; González Rubio, G.; Otero Díaz, L.; Perezzan, Ramiro; Urones Garrote, E.