Department of Biology, Lund Vision Group, Lund University, Sölvegatan 35B, 223 62 Lund, Sweden.
Department of Biology, Lund Vision Group, Lund University, Sölvegatan 35B, 223 62 Lund, Sweden.
Curr Biol. 2022 Jan 24;32(2):438-444.e3. doi: 10.1016/j.cub.2021.10.067. Epub 2021 Nov 30.
Path integration is a general mechanism used by many animals to maintain an updated record of their position in relation to a set reference point. To do this, they continually integrate direction and distance information into a memorized home vector. What remains unclear is how this vector is stored, maintained, and utilized for successful navigation. A recent computational model based on the neuronal circuitry of the insect central complex suggests that home vector memories are encoded across a set of putative memory neurons and maintained through ongoing recurrent neural activity. To better understand the nature of the home vector memory and experimentally assess underlying mechanisms for maintaining it, we performed a series of experiments on the path integrating dung beetle Scarabaeus galenus. We found that, while the directional component of the home vector was maintained for up to 1 h, the distance component of the vector memory decreased gradually over time. Using cold-induced anesthesia, we disrupted the neural activity of beetles that had stored a home vector of known length and direction. This treatment diminished both components of the home vector memory, but by different amounts-the homing beetles lost their distance memory before their directional memory. Together, these findings present new insights into the functional properties of home vector memories and provide the first empirical evidence that a biological process that can be disrupted by cold-induced anesthesia is essential to support homing by path integration.
路径整合是许多动物用来维持其相对于设定参考点的位置更新记录的一种通用机制。为此，它们不断将方向和距离信息整合到记忆中的归巢向量中。目前尚不清楚这个向量是如何存储、维护和用于成功导航的。最近基于昆虫中央复合体的神经元回路的计算模型表明，归巢向量记忆是通过一组假定的记忆神经元进行编码，并通过持续的递归神经活动来维持。为了更好地了解归巢向量记忆的性质并从实验上评估维持它的潜在机制，我们对具有路径整合能力的蜣螂（Scarabaeus galenus）进行了一系列实验。我们发现，虽然归巢向量的方向分量可以维持长达 1 小时，但向量记忆的距离分量会随着时间的推移逐渐减少。通过冷诱导麻醉，我们破坏了储存已知长度和方向的归巢向量的甲虫的神经活动。这种处理方法会同时削弱归巢向量记忆的两个分量，但削弱的程度不同——归巢甲虫在失去方向记忆之前先失去了距离记忆。总的来说，这些发现为归巢向量记忆的功能特性提供了新的见解，并提供了第一个经验证据，表明可以通过冷诱导麻醉破坏的生物过程对于支持路径整合的归巢是必不可少的。
