Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, 14049-900, Brazil.
Núcleo de Neurociências, Department of Physiology and Biophysics, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, 31270-901, Brazil.
Sci Rep. 2018 Jan 22;8(1):1382. doi: 10.1038/s41598-018-19540-6.
The prefrontal cortex integrates a variety of cognition-related inputs, either unidirectional, e.g., from the hippocampal formation, or bidirectional, e.g., with the limbic thalamus. While the former is usually implicated in synaptic plasticity, the latter is better known for regulating ongoing activity. Interactions between these processes via prefrontal neurons are possibly important for linking mnemonic and executive functions. Our work further elucidates such dynamics using in vivo electrophysiology in rats. First, we report that electrical pulses into CA1/subiculum trigger late-onset (>400 ms) firing responses in the medial prefrontal cortex, which are increased after induction of long-term potentiation. Then, we show these responses to be attenuated by optogenetic control of the paraventricular/mediodorsal thalamic area. This suggests that recruitment and plasticity of the hippocampal-prefrontal pathway is partially related to the thalamic-prefrontal loop. When dysfunctional, this interaction may contribute to cognitive deficits, psychotic symptoms, and seizure generalization, which should motivate future studies combining behavioural paradigms and long-range circuit assessment.
前额叶皮层整合了各种认知相关的输入，这些输入可以是单向的，例如来自海马结构，也可以是双向的，例如来自边缘丘脑。前者通常与突触可塑性有关，后者则以调节持续活动而闻名。通过前额叶神经元进行这些过程之间的相互作用可能对于连接记忆和执行功能很重要。我们的工作使用大鼠体内电生理学进一步阐明了这种动力学。首先，我们报告说，电脉冲进入 CA1/下托会引发内侧前额叶皮层的迟发性（>400 毫秒）放电反应，在诱导长时程增强后会增加。然后，我们表明这些反应会被房室旁核/内侧丘脑区域的光遗传控制减弱。这表明海马-前额叶通路的募集和可塑性部分与丘脑-前额叶环路有关。当这种相互作用出现功能障碍时，可能会导致认知缺陷、精神病症状和癫痫发作扩散，这应该促使未来的研究将行为范式和长程电路评估结合起来。
