Browsing by Author "Gajardo Gómez, Rosario"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Cannabinoids Prevent the Amyloid beta-Induced Activation of Astroglial Hemichannels: A Neuroprotective Mechanism
    (2017) Gajardo Gómez, Rosario; Labra, Valeria C.; Maturana, Carola J.; Shoji Sánchez, Kenji Fabricio; Sáez, Juan Carlos; Orellana Roca, Juan Andrés
  • Thumbnail Image
    Item
    Connexin 43 Hemichannel Activity Promoted by Pro-Inflammatory Cytokines and High Glucose Alters Endothelial Cell Function
    (2018) Sáez, Juan Carlos; Contreras-Duarte, Susana; Gomez, Gonzalo I.; Labra, Valeria C.; Santibanez, Cristian A.; Gajardo Gómez, Rosario; Avendano, Beatriz C.; Diaz, Esteban F.; Montero, Trinidad D.; Velarde, Victoria; Orellana Roca, Juan Andrés
  • Thumbnail Image
    Item
    Connexins and pannexins : new insights into microglial functions and dysfunctions
    (2016) Gajardo Gómez, Rosario; Labra, V.; Orellana Roca, Juan Andrés
  • Thumbnail Image
    Item
    HIV GP120 protein increases the function of connexin 43 hemichannels and pannexin-1 channels in astrocytes: Repercussions on astroglial function
    (2020) Gajardo Gómez, Rosario; Santibáñez, Cristian A.; Labra Ramírez, Valeria Cristina; Gómez, Gonzalo I.; Eugenin, Eliseo A.; Orellana Roca, Juan Andrés
    At least half of human immunodeficiency virus (HIV)-infected individuals suffer from a wide range of cognitive, behavioral and motor deficits, collectively known as HIV-associated neurocognitive disorders (HAND). The molecular mechanisms that amplify damage within the brain of HIV-infected individuals are unknown. Recently, we described that HIV augments the opening of connexin-43 (Cx43) hemichannels in cultured human astrocytes, which result in the collapse of neuronal processes. Whether HIV soluble viral proteins such as gp120, can regulate hemichannel opening in astrocytes is still ignored. These channels communicate the cytosol with the extracellular space during pathological conditions. We found that gp120 enhances the function of both Cx43 hemichannels and pannexin-1 channels in mouse cortical astrocytes. These effects depended on the activation of IL-1 beta/TNF-alpha, p38 MAP kinase, iNOS, cytoplasmic Ca2+ and purinergic signaling. The gp120-induced channel opening resulted in alterations in Ca2+ dynamics, nitric oxide production and ATP release. Although the channel opening evoked by gp120 in astrocytes was reproduced in ex vivo brain preparations, these responses were heterogeneous depending on the CA1 region analyzed. We speculate that soluble gp120-induced activation of astroglial Cx43 hemichannels and pannexin-1 channels could be crucial for the pathogenesis of HAND.
  • Thumbnail Image
    Item
    Identification of electroencephalography and psychophysical parameters with potential diagnostic use for suicidal patients
    (2023) Gajardo Gómez, Rosario; Aboitiz, Francisco; Pontificia Universidad Católica de Chile. Facultad de Medicina
    Suicide is a global public health concern, with women showing a higher prevalence of suicidal thoughts and attempts compared to men. The shift from suicidal ideation to suicidal attempts involves individual, social, and environmental factors, with impulsivity playing a significant role. Early detection of suicide risk is vital, and early biological markers are urgently needed. An interesting candidate marker is the Loudness Dependence of Auditory Evoked Potentials (LDAEP). While LDAEP shows promise in characterizing patients with depression and impulsivity, it has been largely used with emotionally neutral stimuli. Thus, its characterization in response to emotional auditory stimuli could represent an improvement as a neuropsychiatric risk marker. This study addresses this gap by examining neural and emotional processing in female patients with depressive episodes, suicidal ideation, and recent suicidal attempts. Our hypothesis posits that female patients with depressive episodes and recent suicide attempts will exhibit greater impairments in neural and emotional processing, but lower levels of impulsivity compared to female patients with depressive episodes and suicidal ideation but no recent suicida attempts. To achieve this, this study explored the interplay between behavior, electrophysiology, and psychology in 19 female patients, including 10 subjects with Suicidal Ideation (SI) and 9 subjects with Suicide Attempt (SA), all admitted to the psychiatric hospitalization service of San Carlos de Apoquindo Clinical Center. Socioeconomic and demographic factors were comparable between groups, emphasizing the role of individual experiences. The LDAEP component was assessed in response to tonal and emotional auditory stimuli. False alarms, accuracy, and response times were analyzed. A multiple correlation matrix with false discovery rate (FDR) correction revealed associations between clinical psychological evaluations and electrophysiological data. Linear regression analysis uncovered mediating factors shaping these relationships. All patients had depressive episodes, with common triggers being suicidal thoughts, interpersonal issues, family conflicts, and academic stressors. Most had received therapy, and self-harm was prevalent, especially in SA. Findings revealed shorter reaction times (RT) in SI the group to neutral stimuli, suggesting impulsive tendencies. RT frequency distributions in the SA group displayed a faster response to negative stimuli, indicating a negative bias associated with depressive states. LDAEP analysis of tonal and emotional stimuli showed no significant differences between groups. However, the SI group demonstrated a tendency towards a greater tonal LDAEP. SI showed increased P2 amplitude, signifying enhanced perceptual attentional processing of emotional information. A deflection in the P3 component suggested reduced attentional allocation, diminished cognitive processing, and a lower level of emotional content evaluation. A consistent plateau in P2-P3 amplitudes was observed for both positive and negative stimuli, indicating a blunted affective response and decreased cognitive and emotional flexibility. SI demonstrated a stronger correlation between impulsivity and depression, while SA showed associations between hopelessness, impulsivity, and depression. Childhood trauma, particularly sexual aggression, exacerbated pathology in SI. Family support was a significant factor influencing depressive symptoms in both groups. SI exhibited a negative correlation between depressive symptoms and hopelessness, influenced by protective factors. Significant correlations were found between electrophysiological and psychological variables. In SI, cognitive factors related to life satisfaction affected neural responses, while hopelessness and childhood trauma influenced depressive symptoms. In SA, depressive symptoms, hopelessness, and impulsivity were strongly correlated, emphasizing the need for clinical intervention. The results highlight the complex interplay of impulsivity, depressive states, cognitive processing, and emotional regulation in shaping suicidal ideation and suicide attempts. Further investigations should continue to explore the intricate mechanisms underlying suicidality, ultimately leading to more effective strategies for identifying and supporting individuals at risk of suicide.
  • Thumbnail Image
    Item
    The Neuroglial Dialog Between Cannabinoids and Hemichannels
    (2018) Labra, Valeria C.; Santibanez, Cristian A.; Gajardo Gómez, Rosario; Diaz, Esteban F.; Gomez, Gonzalo, I; Orellana Roca, Juan Andrés