Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; Wyoming Sensory Biology Center of Biomedical Research Excellence, University of Wyoming, Laramie, WY 82071, USA.
Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA; Wyoming Sensory Biology Center of Biomedical Research Excellence, University of Wyoming, Laramie, WY 82071, USA.
Cell Rep. 2024 Sep 24;43(9):114672. doi: 10.1016/j.celrep.2024.114672. Epub 2024 Aug 27.
Cortical neurons encode both sensory and contextual information, yet it remains unclear how experiences modulate these cortical representations. Here, we demonstrate that trace eyeblink conditioning (TEC), an aversive associative-learning paradigm linking conditioned (CS) with unconditioned stimuli (US), finely tunes cortical coding at both population and single-neuron levels. Initially, we show that the primary somatosensory cortex (S1) is necessary for TEC acquisition, as evidenced by local muscimol administration. At the population level, TEC enhances activity in a small subset (∼20%) of CS- or US-responsive primary neurons (rPNs) while diminishing activity in non-rPNs, including locomotion-tuned or unresponsive PNs. Crucially, TEC learning modulates the encoding of sensory versus contextual information in single rPNs: CS-responsive neurons become less responsive, while US-responsive neurons gain responses to CS. Moreover, we find that the cholinergic pathway, via nicotinic receptors, underlies TEC-induced modulations. These findings suggest that experiences dynamically tune cortical representations through cholinergic pathways.
皮质神经元编码感觉和上下文信息，但经验如何调节这些皮质表示仍不清楚。在这里，我们证明了痕迹性眨眼条件反射（TEC），一种将条件刺激（CS）与非条件刺激（US）联系起来的厌恶联想学习范式，可以在群体和单个神经元水平上精细地调整皮质编码。最初，我们表明初级体感皮层（S1）是 TEC 获得所必需的，这一点可以通过局部 muscimol 给药得到证明。在群体水平上，TEC 增强了一小部分（约 20%）对 CS 或 US 有反应的初级神经元（rPN）的活动，同时减少了非 rPN 的活动，包括运动调谐或无反应的 PN。至关重要的是，TEC 学习调节了单个 rPN 中感觉与上下文信息的编码：CS 反应神经元的反应性降低，而 US 反应神经元对 CS 的反应性增加。此外，我们发现，通过烟碱型受体，胆碱能通路是 TEC 诱导的调节的基础。这些发现表明，经验通过胆碱能通路动态地调整皮质表示。
