RAQUEL CHACON RUIZ MARTINEZ
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Psiquiatria, Hospital das Clínicas, Faculdade de Medicina
LIM/23 - Laboratório de Psicopatologia e Terapêutica Psiquiátrica, Hospital das Clínicas, Faculdade de Medicina
LIM/23 - Laboratório de Psicopatologia e Terapêutica Psiquiátrica, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Active vs. reactive threat responding is associated with differential c-Fos expression in specific regions of amygdala and prefrontal cortex(2013) MARTINEZ, Raquel C. R.; GUPTA, Nikita; LAZARO-MUNOZ, Gabriel; SEARS, Robert M.; KIM, Soojeong; MOSCARELLO, Justin M.; LEDOUX, Joseph E.; CAIN, Christopher K.Active avoidance (AA) is an important paradigm for studying mechanisms of aversive instrumental learning, pathological anxiety, and active coping. Unfortunately, AA neurocircuits are poorly understood, partly because behavior is highly variable and reflects a competition between Pavlovian reactions and instrumental actions. Here we exploited the behavioral differences between good and poor avoiders to elucidate the AA neurocircuit. Rats received Sidman AA training and expression of the activity-dependent immediate-early gene c-fos was measured after a shock-free AA test. Six brain regions with known or putative roles in AA were evaluated: amygdala, periaqueductal gray, nucleus accumbens, dorsal striatum, prefrontal cortex (PFC), and hippocampus. Good avoiders showed little Pavlovian freezing and high AA rates at test, the opposite of poor avoiders. Although c-Fos activation was observed throughout the brain, differential activation was found only in subregions of amygdala and PFC. Interestingly, c-Fos correlated with avoidance and freezing in only five of 20 distinct areas evaluated: lateral amygdala, central amygdala, medial amygdala, basal amygdala, and infralimbic PFC. Thus, activity in specific amygdala-PFC circuits likely mediates the competition between instrumental actions and Pavlovian reactions after AA training. Individual differences in AA behavior, long considered a nuisance by researchers, may be the key to elucidating the AA neurocircuit and understanding pathological response profiles.
- Intraoperative Dopamine Release During Globus Pallidus Internus Stimulation in Parkinson's Disease(2013) MARTINEZ, Raquel C. R.; HAMANI, Clement; CARVALHO, Milene Cristina de; OLIVEIRA, Amanda Ribeiro de; ALHO, Eduardo; NAVARRO, Jessie; GHILARDI, Maria Gabriela dos Santos; BOR-SENG-SHU, Edson; HEINSEN, Helmut; OTOCH, Jose Pinhata; BRANDAO, Marcus Lira; BARBOSA, Egberto Reis; TEIXEIRA, Manoel Jacobsen; FONOFF, Erich TalamoniBackgroundIt is still unclear whether dopamine (DA) levels correlate with Parkinson's disease (PD) severity or play a role in the mechanisms of high-frequency stimulation (HFS). MethodsWe have used microdialysis to record pallidal DA in 5 patients with PD undergoing microelectrode-guided pallidotomy. ResultsWe found that patients with more severe disease and, consequently, lower pallidal DA did poorly after pallidal lesions. In the operating room, 4 of 5 patients had a significant increase in DA levels during HFS (600%, on average). To test the hypothesis that DA was important for the effects of stimulation, we correlated the amelioration in rigidity observed in the operating room with pallidal DA release. Though rigidity was 56% better during stimulation, no correlation was found between such an improvement and DA release. ConclusionsThese findings suggest that additional mechanisms not directly dependent on pallidal DA release may be involved in the clinical effects of HFS of the globus pallidus internus. (c) 2013 International Parkinson and Movement Disorder Society
- Detection of a Temporal Error Triggers Reconsolidation of Amygdala-Dependent Memories(2013) DIAZ-MATAIX, Lorenzo; MARTINEZ, Raquel Chacon Ruiz; SCHAFE, Glenn E.; LEDOUX, Joseph E.; DOYERE, ValerieUpdating memories is critical for adaptive behaviors, but the rules and mechanisms governing that process are still not well defined. During a limited time window, the reactivation of consolidated aversive memories triggers memory lability and induces a plasticity-dependent reconsolidation process in the lateral nucleus of amygdala (LA) [1-5]. However, whether new information is necessary for initiating reconsolidation is not known. Here we show that changing the temporal relationship between the conditioned stimulus (CS) and unconditioned stimulus (US) during reactivation is sufficient to trigger synaptic plasticity and reconsolidation of an aversive memory in the LA. These findings demonstrate that time is a core part of the CS-US association and that new information must be presented during reactivation in order to trigger LA-dependent reconsolidation processes. In sum, this study provides new basic knowledge about the precise rules governing memory reconsolidation of aversive memories that might be used to treat traumatic memories.