Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a ...Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.展开更多
Background:Synchronization across neural circuits is inextricably associated with brain function and pathology.Although not largely explored,this framework can be applied to baseline anxiety and its disorder,which is ...Background:Synchronization across neural circuits is inextricably associated with brain function and pathology.Although not largely explored,this framework can be applied to baseline anxiety and its disorder,which is characterized by aberrant levels of synchronization between the amygdala nuclei and other areas of the extended amygdala,particularly the bed nucleus of the stria terminalis(BNST)and those outside this complex.Here,we aimed to test the hypothesis that a temporally complex form of electrical stimulation(non-periodic stimulation[NPS])of the amygdala,specifically designed to disrupt hypersynchronous activity in epilepsy,a major comorbidity of pathological anxiety,may reduce its symptoms.Methods:Wistar rats were subjected to a physical restriction protocol model of stress to induce pathological anxiety and were assessed using the gold standard elevated plus maze(EPM)and open field(OF)tests.Result:In all criteria measured by the tests,NPS animals displayed reduced levels of anxiety-related symptoms,back at physiological levels.Conclusions:Considering the known effects and mechanisms of NPS on epileptic phenomena,we hypothesized that the therapeutic effects were achieved by desynchronization(or normalization of synchronism levels)across brain circuits involving the amygdala,BNST,and others.Overall,past and present findings suggest that NPS may be considered as a therapeutic alternative for the treatment of anxiety disorders.展开更多
基金supported by the National Natural Science Foundation of China(61074131,91132722)the Doctoral Fund of the Ministry of Education of China(20101202110007)
文摘Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role. This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event. Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80% correct rate in a working memory task. Then a 16-channel microelectrode array was implanted in the prefrontal cortex. After recovery, neuronal population activity was recorded during the task, using the Cerebus data-acquisition system. Spatio-temporal trains of action potentials were obtained from the original neuronal population signals. Results During the Y-maze working memory task, some neurons showed significantly in- creased firing rates and evident neuronal ensemble activity. Moreover, the anticipatory activity was associated with the delayed alternate choice of the upcoming movement. In correct trials, the averaged pre-event firing rate （10.86 ± 1.82 spikes/ bin） was higher than the post-event rate （8.17 ± 1.15 spikes/bin） （P 〈0.05）. However, in incorrect trials, the rates did not differ. Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.
基金supported by the Fundaç~ao de Amparo a Pesquisa de Minas Gerais,Brazil(FAPEMIG)(No.APQ 02485-15)the Conselho Narcional de Desenvolvimento Científico e Tecnologico(CNPq)(schol-arship for scientific studies to the first author).
文摘Background:Synchronization across neural circuits is inextricably associated with brain function and pathology.Although not largely explored,this framework can be applied to baseline anxiety and its disorder,which is characterized by aberrant levels of synchronization between the amygdala nuclei and other areas of the extended amygdala,particularly the bed nucleus of the stria terminalis(BNST)and those outside this complex.Here,we aimed to test the hypothesis that a temporally complex form of electrical stimulation(non-periodic stimulation[NPS])of the amygdala,specifically designed to disrupt hypersynchronous activity in epilepsy,a major comorbidity of pathological anxiety,may reduce its symptoms.Methods:Wistar rats were subjected to a physical restriction protocol model of stress to induce pathological anxiety and were assessed using the gold standard elevated plus maze(EPM)and open field(OF)tests.Result:In all criteria measured by the tests,NPS animals displayed reduced levels of anxiety-related symptoms,back at physiological levels.Conclusions:Considering the known effects and mechanisms of NPS on epileptic phenomena,we hypothesized that the therapeutic effects were achieved by desynchronization(or normalization of synchronism levels)across brain circuits involving the amygdala,BNST,and others.Overall,past and present findings suggest that NPS may be considered as a therapeutic alternative for the treatment of anxiety disorders.
