Jedrasiak-Cape Izabela, Rybicki-Kler Chloe, Brooks Isla, Ghosh Megha, Brennan Ellen K W, Kailasa Sameer, Ekins Tyler G, Rupp Alan, Ahmed Omar J
Dept. of Psychology, University of Michigan, Ann Arbor, MI 48109, United States.
Dept. of Psychology, University of Michigan, Ann Arbor, MI 48109, United States; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, United States.
Prog Neurobiol. 2025 Jul 8;251:102804. doi: 10.1016/j.pneurobio.2025.102804.
Cholinergic receptor activation enables the persistent firing of cortical pyramidal neurons, providing a key cellular basis for theories of spatial navigation involving working memory, path integration, and head direction encoding. The granular retrosplenial cortex (RSG) is important for spatially-guided behaviors, but how acetylcholine impacts RSG neurons is unknown. Here, we show that a transcriptomically, morphologically, and biophysically distinct RSG cell-type - the low-rheobase (LR) neuron - has a very distinct expression profile of cholinergic muscarinic receptors compared to all other neighboring excitatory neuronal subtypes. LR neurons do not fire persistently in response to cholinergic agonists, in stark contrast to all other principal neuronal subtypes examined within the RSG and across midline cortex. This lack of persistence allows LR neuron models to rapidly compute angular head velocity (AHV), independent of cholinergic changes seen during navigation. Thus, LR neurons can consistently compute AHV across brain states, highlighting the specialized RSG neural codes supporting navigation.
胆碱能受体激活可使皮质锥体细胞持续放电，为涉及工作记忆、路径整合和头部方向编码的空间导航理论提供关键的细胞基础。颗粒状 retrosplenial 皮质（RSG）对空间引导行为很重要，但乙酰胆碱如何影响 RSG 神经元尚不清楚。在这里，我们表明，一种在转录组学、形态学和生物物理学上都不同的 RSG 细胞类型——低阈强度（LR）神经元，与所有其他相邻的兴奋性神经元亚型相比，具有非常独特的胆碱能毒蕈碱受体表达谱。与 RSG 内和中线皮质中检查的所有其他主要神经元亚型形成鲜明对比的是，LR 神经元不会因胆碱能激动剂而持续放电。这种缺乏持续性使得 LR 神经元模型能够快速计算角头速度（AHV），而与导航过程中观察到的胆碱能变化无关。因此，LR 神经元可以在不同脑状态下持续计算 AHV，突出了支持导航的特殊 RSG 神经编码。
