PSY5101H: The neurobiology of engrams

Instructor: Paul Frankland (


Memories are thought to be encoded as enduring physical changes, or ‘engrams’, in the brain. Karl Lashley was among the first to use an empirical systematic approach in an attempt to localize an engram. Famously, his search proved unsuccessful, and his conclusion—that the engram is elusive—became widely influential.  From today’s perspective, we appreciate that this elusivity is, at least in part, due to the sparse, distributed and dynamic nature of memory representations in the brain, making engrams challenging to identify and ‘pin down’ using traditional neuroscientific methods.  However, new mouse genetic tools have recently been developed which provide unprecedented opportunities to visualize and manipulate defined brain regions and specific cell populations. The goal of this course is to discuss to what extent these contemporary studies have brought us closing to finding the engram.


Tuesdays 2-4 pm in Sidney Smith Hall, room 560A


5101 schedule updated (March 1)


Students will present and discuss recent ‘engram’ papers. For each class, 2 papers have been selected. For each paper a presenter will be assigned, as well as a discussant. The presentation should be 30-40 minutes followed by 10-15 minutes of discussion.

Non-presenters will read the papers before the class and submit a 0.5-1 page summary of each paper, including 3-4 discussion points/comments/questions. These are to be emailed to the instructor ( no later than 11:59 pm on Monday evening.


1) Presentations (30%). Student will get to present twice during the course. Each presentation is worth 15% of the final grade.

2) Participation in class discussions (40%). This grade will be based on the weekly summaries (20%) as well as ability to lead and participate in class discussions (20%).

3) Assignments (30%). There will be two assignments. Students will write “New and Views” style commentaries (~1000 words) on recent engram papers. The first is due during reading week. The second is due at the end of term. Both contribute 15% to the final grade.


Detailed schedule

Week 1,  January 12: Frankland lecture FINAL (Frankland), course organization

Historical overview of engram studies focusing on the work of Semon, Lashley and Penfield

Week 2,  January 19:  Seeing the engram, immediate early genes

[Guzowski et al], [Reijmers et al]

Week 3,  January 26:  Seeing the engram, replay

[Singer et al], [Tambini et al]

Week 4,  February 2:  Erasing the engram

[Zhou et al], [Nabavi et al]

Week 5,  February 9:  Reorganizing the engram

[Tayler et al], [Denny et al]

Reading week,  February 16:  Assignment 1

Week 6,  February 23:  Distributed engrams

[Tanaka et al], [Wheeler et al]

Week 7, March 1: Erasing pathological engrams

[Ramirez et al (2015)], [Hsiang et al]

Week 8,  March 8:  Artificially expressing the engram

[Liu et al], [Kim et al]

Week 9,  March 15:  Creating false engrams

[ramirez et al (2013)], [de Lavilleon et al]

Week 10,  March 22:  Allocation

[Han et al], [Yiu et al]

Week 11,  March 29:  Interacting engrams

[Tse et al (2007)Tse et al (2011)], [Richards et al]

Week 12, April 5:  Assignment 2