Devienne Gabrielle, Picaud Sandrine, Cohen Ivan, Piquet Juliette, Tricoire Ludovic, Testa Damien, Di Nardo Ariel A, Rossier Jean, Cauli Bruno, Lambolez Bertrand
Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine-Institut de Biologie Paris Seine, Sorbonne Universités, Paris, 75005, France.
Centre for Interdisciplinary Research in Biology, Collège de France, Centre National de la Recherche Scientifique, Unite Mixte de Recherche 7241, Institut National de la Santé et de la Recherche Médicale U1050, PSL Research University, Paris, 75005, France.
J Neurosci. 2021 Jul 7;41(27):5779-5790. doi: 10.1523/JNEUROSCI.0434-21.2021.
Perineuronal net (PNN) accumulation around parvalbumin-expressing (PV) inhibitory interneurons marks the closure of critical periods of high plasticity, whereas PNN removal reinstates juvenile plasticity in the adult cortex. Using targeted chemogenetic approaches in the adult mouse visual cortex, we found that transient inhibition of PV interneurons, through metabotropic or ionotropic chemogenetic tools, induced PNN regression. EEG recordings indicated that inhibition of PV interneurons did not elicit unbalanced network excitation. Likewise, inhibition of local excitatory neurons also induced PNN regression, whereas chemogenetic excitation of either PV or excitatory neurons did not reduce the PNN. We also observed that chemogenetically inhibited PV interneurons exhibited reduced PNN compared with their untransduced neighbors, and confirmed that single PV interneurons express multiple genes enabling individual regulation of their own PNN density. Our results indicate that PNN density is regulated in the adult cortex by local changes of network activity that can be triggered by modulation of PV interneurons. PNN regulation may provide adult cortical circuits with an activity-dependent mechanism to control their local remodeling. The perineuronal net is an extracellular matrix, which accumulates around individual parvalbumin-expressing inhibitory neurons during postnatal development, and is seen as a barrier that prevents plasticity of neuronal circuits in the adult cerebral cortex. We found that transiently inhibiting parvalbumin-expressing or excitatory cortical neurons triggers a local decrease of perineuronal net density. Our results indicate that perineuronal nets are regulated in the adult cortex depending on the activity of local microcircuits. These findings uncover an activity-dependent mechanism by which adult cortical circuits may locally control their plasticity.
围绕表达小白蛋白(PV)的抑制性中间神经元的神经元周围网(PNN)积累标志着高可塑性关键期的结束,而去除PNN可恢复成年皮质中的幼年可塑性。通过在成年小鼠视觉皮质中使用靶向化学遗传学方法,我们发现通过代谢型或离子型化学遗传学工具对PV中间神经元进行短暂抑制会诱导PNN消退。脑电图记录表明,抑制PV中间神经元不会引发网络兴奋失衡。同样,抑制局部兴奋性神经元也会诱导PNN消退,而对PV或兴奋性神经元进行化学遗传学兴奋并不会降低PNN。我们还观察到,与未转导的相邻细胞相比,化学遗传学抑制的PV中间神经元表现出较低的PNN,并证实单个PV中间神经元表达多种基因,能够单独调节其自身的PNN密度。我们的结果表明,在成年皮质中,PNN密度受网络活动的局部变化调节,这种变化可由PV中间神经元的调节触发。PNN调节可能为成年皮质回路提供一种依赖活动的机制来控制其局部重塑。神经元周围网是一种细胞外基质,在出生后发育过程中围绕单个表达小白蛋白的抑制性神经元积累,被视为阻止成年大脑皮质神经元回路可塑性的屏障。我们发现,短暂抑制表达小白蛋白的或兴奋性皮质神经元会触发神经元周围网密度的局部降低。我们的结果表明,在成年皮质中,神经元周围网根据局部微回路的活动进行调节。这些发现揭示了一种依赖活动的机制,成年皮质回路可能通过该机制局部控制其可塑性。