Interview with Jim Ranck, discoverer of Head-Direction cells

May 7, 2019,  Andre Fenton and I interview Jim Ranck. The interview is quite long — 90 minutes — and is organized in a decade-by-decade manner. For each segment we discuss Jim’s personal history, his scientific accomplishments, and some major events in Neuroscience.

watch, above, or go directly to youtube: https://youtu.be/i6hIVqXPNdQ

The interview contains lots of hippocampal minutia. Best suited for people in the field … but I think there are other gems.

The timeline is something like this:

0:00:00    1930-40s birth thru college: 
0:04:50    1950s  med school, Univ chicago, Public Health 
0:20:10    1960s  Univ Washington, Biophysics, Brain Impedance, Mich
0:31:00    1970s  Hippocampal Neurons, O'Keefe & Nadel
                  Phil Best, place cells are real
0:48:00    1975   Move to Brooklyn, single neurons
1:08:43    1980s  (part 1) computerized data collection and
                  analysis
1:10:40    1980s  (part 2) Head-Direction cells. Ego and allocentric
1:22:55    1990s  Cognitive Neuroscience, the book.

Most important segment is on discovery and description of Head-Direction Cells,
1:10:40 – 1:23:00

Are we conscious when driving?

driving

Or are we zombies?

Frequently, perhaps  most of the time, I feel I drive on “autopilot”. That is, I drive without awareness of driving. This is especially true when driving along highly familiar routes, such as my 1-hour commute from NJ to Brooklyn. While driving, my clear conscious experience is typically on something else: perhaps what’s on the radio, perhaps a problem at work, or a personal relationship. Clearly, however, my sensory motor system is working. I’m steering, turning, responding to other cars, etc. Others might suggest that I’m “multitasking”, switching between 2 conscious modes, but I don’t feel that’s the case.  Continue reading

The Hippocampus as a Cognitive Map: the book

book coverA few weeks ago the Nobel Prize Committee announced that John O’Keefe, Edvard Moser and May-Britt Moser would be the recipients of the 2014 prize for Physiology and Medicine for their work in deciphering the code of neurons in the rat hippocampal region. The work is frequently summarized as revealing the functioning of the brain’s GPS system at the level of neurons and networks of neurons.  While the GPS part is true, the work is far broader, giving insights into the neural substrate of broad areas of cognition that include memory, planning, creativity and internal thought. What follows are some of my thoughts, focusing on historical roots of the discoveries. Emphasis is on the significance of John O’Keefe and Lynn Nadel’s 1978 book, “The Hippocampus as a Cognitive Map”1.

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What is episodic memory good for?

The function of learning is clear: modifying behavior through experience. Memory, the storage of information that supports learning, is clearly necessary and valuable. Current psychology and neuroscience tell us that there are two memory systems enabled by separate neural systems. Procedural memory relies on reward circuitry and trial-and-error processes to mold efficient behaviors. Episodic memory stores specifc events in the life of the individual — but for what purpose? Continue reading

What is Cognition?

snoopy2In 1981 I was an eager post-doctoral fellow, learning to record place cell’s in Jim Ranck’s lab and beginning to understand John O’Keefe and Lynn Nadel’s “Cognitive Map” theory of the hippocampus. One afternoon, while I had a rat in the maze and watched traces of action potentials sweep by on the oscilloscope, Jim Ranck looked over my should and said …

“This is terrific! Place cells are the gateway to understanding how the brain produces cognition.”1

This was both inspirational and opaque. Continue reading

Head-Direction Cell Assembies have Attractor Properties During Locomotion and Sleep

Poster: Organization of the neuronal assemblies in the anterior thalamus coding for head direction   326.14 (Mon Morning)
Authors: A. Peyrache, M. Lacorix, P. Petersen, G. Buzsaki; NYU

Head-direction cells are neurons that fire when ever a rat’s head is pointed in a particular direction. Discovered by Jim Ranck and first reported at SfN 29 years ago today’s findings are a major update, confirming and extending the cohesive properties of head-direction cell networks.

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Grid Cells, Place Cells and Navigation

grid module small I’ve made a posting on the BrainsFacts Blog site on Grid Cells and Path Integration. Aimed at High School and College students, but I think it gets complicated. Write your comments here!

Also, planning a third post or the Modular organization of Grid Cells. Based on new paper “Specific evidence of low-dimensional continuous attractor dynamics in grid cells” (Yoon et al) published in Nature Neuroscience.

Are Place-to-Memory Associations a 2-way Street?

two way narrowPeople who study memory are familiar with the concept of a Memory Palace, a memory scheme for storing information in remembered places. The Memory Palace story is beautifully described in Joshua Foer’s book Moonwalking With Einstein (although it wasn’t clear to me if Einstein was walking on the moon or walking with Michael Jackson). For millennia, mnenonic super stars have memorized gargantuan lists by associating each list item with a location in a virtual home or palace. During learning, the mnemonicist imagines walking through the palace and placing each item in a particular location. At the time of recall, the memorizer imagines walking through the memory palace and, as if by magic, seeing each item where it had been placed. According to this notion, the ability to associate places to content is natural and fairly easy to master. So easy that Joshua Foer, who had no obvious memory potential, became a national memory champion by mastering the technique. I find the accounts impressive and extremely convincing, although I’ve failed miserably when trying to do this. Overall, the Memory Palace phenomenon suggests a strong natural link between location and memory. Some have taken this linkage to suggest that place serves as in indexing system for memory — a kind of lookup table. A point I’ll return to.

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Optical Recording of Maps in the Hippocampus

(Updated with comparison to Mankin et al Feb 20; in red text)

“Long-term dynamics of CA1 Hippocampal Place Codes” is an important study published in the current issue of Nature Neuroscience. The paper is noteworthy in terms of technical achievement, theoretical implications and the potential for future work

headstage

Headstage on mouse brain. Ziv et al fig 1a.

First, the technical achievement. Ziv et al, working in Mark Schnitzer’s group at Stanford have managed to record the firing activity of hundreds of hippocampal neurons over a period of approximately one month. They do this by permanently mounting a miniature camera on the mouse’s head and using Ca+ imaging to identify the firing pattern of each neuron. Continue reading