23 Jan 14
http://medicalxpress.com/news/2014-01-breakthrough-scientists-molecules-morph-memories.html
"...Einstein researchers developed a mouse model in which they fluorescently tagged all molecules of messenger RNA (mRNA) that code for beta-actin protein – an essential structural protein found in large amounts in brain neurons and considered a key player in making memories...."
If you watch the video on the link, you can make out the movement of individual mRNA molecules moving through the neuron connections because they are giving off florescent light under the microscope -quite a fascinating sight.