Can memory exist outside of brain and be transferred? Historical review, issues & ways forward.

Learning and memory are among the executive functions attributed to intelligent forms of life. Unfortunately, there is a lack of clear understanding regarding the underlying mechanisms governing these functions. Most of the modern day scientists attribute these functions solely to brain. However, in the latter half of last century, a number of reports suggested existence of extra-cranial memory and potential of its transfer between animals. Some have linked this phenomenon to RNA while others believed that peptides were responsible. The terms like "educated RNA" and "scotophobin" were coined. This atypical work involving flatworms, yeast RNA and scotophobin was received with deep skepticism and ultimately disregarded. However, the recent reproduction of some of this earlier work by scientists at Tufts University has reignited the debate on the mechanisms of learning and memory. Keeping this in view, we believe it is high time to summarize this historical work and discuss the possibilities to delineate these atypical claims. The objective is to incite the present day researchers to explore this opportunity under the perspective of newer advancements in science.