lostInTheCosmosv1“You are standing by your paper-tube in Englewood reading the headlines. Your neighbor comes out to get his paper. You look at him sympathetically. You know he has been having severe chest pains and is facing coronary bypass surgery. But he is not acting like a cardiac patient this morning. Over he jogs in his sweat pants, all smiles. He has triple good news. His chest ailment turned out to be a hiatal hernia, not serious. He’s got a promotion and is moving to Greenwich, where he can keep his boat in the water rather than on a trailer. “Great, Charlie! I’m really happy for you.” Are you happy for him?

(a) Yes. Unrelievedly good news. Surely it is good news all around that Charlie is alive and well and not dead or invalided. Surely, too, it is good for him and not bad for you if he also moves up in the world, buys a house in Greenwich where he can keep a 25-foot sloop moored in the Sound rather than a 12-foot Mayflower on a trailer in the garage in Englewood.

(b) Putatively good news but— but what? But the trouble is, it is good news for Charlie, but you don’t feel so good.

— Walker Percy’s (1983) “Lost in the Cosmos: The last Self-Help Book” [1]

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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

Do Grid Cells Drive Place Cells?

Poster: Hippocampal remapping involves competition between entorhinal inputs – SfN Tuesday Morning: 576.20

Authors: J. Dickinson, A. Weible, D. Rowland, C. Kentros

Place cells are recorded in CA1 and CA3 fields of the hippocampus. The major afferents to the hippocampus come from entorhinal cortex. When grid cells were first described in recordings from layer 2 of medial entorhinal cortex it was largely assumed that place cell patterns arose from through a summation of grid cell inputs.  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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Passive Versus Active Movement in Grid Cells and Head Direction Cells

Poster: Passive Transport Disrupts Grid Cell Firing Patterns. Shawn Winter and Jeff Taube.

rat in cartBoth Grid Cells and Head Direction Cells are thought to be path integrators. That is, each cell type is thought to be driven as a function of the animal’s movement. For head-direction cells firing is thought to be driven by rotational movement; for grid cells a combination of rotation and translation. There are distinct sources of self-movement information: motor action plans, proprioception, and feedback from the environment. Winter and Taube sought to dissect these by removing “action plans” (and some proprioception) by comparing firing in these cell types during passive and active movement. Continue reading