美国哥伦比亚大学Andrew J. P. Fink等研究人员合作发现初级嗅觉皮层的代表性漂移。相关论文于2021年6月9日在线发表在《自然》杂志上。
研究人员报道了持续数周的单个单位的电生理记录结果，用于检查小鼠梨状皮层中气味诱发反应的稳定性。尽管梨状皮层的活动可用于随时区分气味剂，但气味引起的反应会在数天到数周内漂移。在第一个记录日训练的线性分类器的性能在32天后接近机会水平。恐惧条件反射并不能稳定气味诱发的反应。每天接触相同的气味会减慢漂移的速度，但是当停止接触时，速度再次增加。
这种持续漂移的演示提出了梨状皮层在气味感知中的作用的问题。这种不稳定性可能反映了梨状皮层的非结构化连接，并且可能是其他非结构化皮层的特性。
据了解，知觉恒常性要求大脑保持对感官输入的稳定表征。在嗅觉系统中，初级嗅觉皮层（梨状皮层）的活动被认为决定了气味特性。
附：英文原文
Title: Representational drift in primary olfactory cortex
Author: Carl E. Schoonover, Sarah N. Ohashi, Richard Axel, Andrew J. P. Fink
Issue&Volume: 2021-06-09
Abstract: Perceptual constancy requires the brain to maintain a stable representation of sensory input. In the olfactory system, activity in primary olfactory cortex (piriform cortex) is thought to determine odour identity1,2,3,4,5. Here we present the results of electrophysiological recordings of single units maintained over weeks to examine the stability of odour-evoked responses in mouse piriform cortex. Although activity in piriform cortex could be used to discriminate between odorants at any moment in time, odour-evoked responses drifted over periods of days to weeks. The performance of a linear classifier trained on the first recording day approached chance levels after 32 days. Fear conditioning did not stabilize odour-evoked responses. Daily exposure to the same odorant slowed the rate of drift, but when exposure was halted the rate increased again. This demonstration of continuous drift poses the question of the role of piriform cortex in odour perception. This instability might reflect the unstructured connectivity of piriform cortex6,7,8,9,10,11,12, and may be a property of other unstructured cortices.
DOI: 10.1038/s41586-021-03628-7
Source: https://www.nature.com/articles/s41586-021-03628-7
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
