Leman Daniel P, Cary Brian A, Bissen Diane, Lane Brian J, Shanley M Regis, Wong Nicole F, Bhut Krish B, Turrigiano Gina G
bioRxiv. 2025 Apr 11:2025.04.11.648036. doi: 10.1101/2025.04.11.648036.
Neocortical neurons possess stable firing rate set points to which they faithfully return when perturbed. These set points are established early and are stable through adulthood, suggesting they are immutable. Here we challenge this idea using an ethological vision-dependent prey capture learning paradigm in juvenile rats. This learning required visual cortex (V1), and enhanced tuning of V1 neurons to specific behavioral epochs. Chronic recordings revealed a slow, state-dependent increase in V1 firing that began after learning was complete and persisted for days. This upward firing rate plasticity was gradual, gated by wake states, and in L2/3 was driven by a TNFα-dependent increase in excitatory synapses onto pyramidal neurons - all features of homeostatic plasticity within V1. Finally, TNFα inhibition after learning reduced retention of hunting skills. Thus, naturalistic learning in juvenile animals co-opts homeostatic forms of plasticity to reset firing rate setpoints within V1, in a process that facilitates skill consolidation.
新皮层神经元具有稳定的放电率设定点,受到干扰时它们会忠实地回到这些设定点。这些设定点在早期就已确立,并且在成年期一直保持稳定,这表明它们是不可改变的。在此,我们利用幼鼠的一种依赖视觉的捕食学习行为学范式对这一观点提出质疑。这种学习需要视觉皮层(V1),并增强了V1神经元对特定行为时期的调谐。长期记录显示,V1放电出现缓慢的、依赖状态的增加,这种增加在学习完成后开始,并持续数天。这种放电率的向上可塑性是渐进的,受觉醒状态的门控,并且在第2/3层是由锥体细胞上兴奋性突触的肿瘤坏死因子α(TNFα)依赖性增加驱动的——所有这些都是V1内稳态可塑性的特征。最后,学习后抑制TNFα会降低狩猎技能的保留。因此,幼龄动物的自然学习利用内稳态可塑性形式来重置V1内的放电率设定点,这一过程有助于技能巩固。