Lmst

Hippocampus:Space is a latent sequence
https://www.science.org/doi/10.1126/sciadv.adm8470
https://news.ycombinator.com/item?id=41132023

* mental representation of space: emergent property of latent higher-order sequence learning
* treating space as a sequence resolves numerous phenomena
* place field mapping methodology interprets sequential neuronal responses in Euclidean terms might itself be source of anomalies

https://en.wikipedia.org/wiki/Grid_cell
https://en.wikipedia.org/wiki/Place_cell

#neuroscience #hippocampus #GridCells #PlaceCells #neurobiology #MentalProcesses

@PennamitePLR If you love hexagons you should love #GridCells ! (neurons, seen for example in Rats, that activate in a very regular hexagonal pattern as the rat explores an environment)

@mattnolan Good points… still, when rats do foraging in 2D, they can have very nice grid cells, but as soon as they move on to 3D, still foraging, the grids break down… 🤔

Roddy (from Grieves et al 2021 says that he’s not aware of any continuous attractor model of grid cells that has been extended to 3D but there should be 2 options: 1) either the grids can integrate movements in the z-axis and that should give rise to columns in 3D, or 2) they can’t and the grid should completely break down in 3D. However, the data showed mostly randomly-located spatial fields that were more spatially-stable than chance, so neither of those 🤔 (similar findings by Ginosar et al., 2021 but for MEC cells that were not necessarily grid cells). But maybe there are now more recent CAN models that we are not aware of!

This reminds me that Gily has a new review paper on the role of #GridCells for #Navigation that I #Need2Read: Ginosar et al., 2023

I love #GridCells but I have to say their influence for any neural process is probably highly over-inflated.

When you actually record from #MEC you see there are so many non-grid cells… it’s really a huge contrast to #Hippocampus where most of the cells are going to be #PlaceCells either in the current environment or another.

Some very nice #PlaceCells and #GridCells in this Virtual Reality experiment in #NeuroMice!
#NeuroPreprint from the #ChenLab:

Visual boundary cues, alone, can anchor place and grid cells in virtual reality

Schematics of the VR environment. Different types of cues (floor, wall) can be removed. The mice are head-fixed but can turn their head in the horizontal plane.

Screenshot of example place cells and grid cells in different environmental conditions. They are pretty nice! The grid cells seem particularly disrupted by removal of the wall cues.

@brembs Me 🙋‍♂️

Posters about: #time #eventstructure #events #memory #dynamics #entorhinalcortex #hippocampus #gridcells #placecells #remapping #Neuropixels

A little summary of #Neuroscience-related hashtags?
(Please add any you think of in answer and I’ll edit the list)

.#NeuroArt
.#Neuroscientist / #Neuroscientists
.#NeuroRat (yep, I’m pretty much the only one using this one)

.#NeuroJobs

The cell types:
.#PlaceCells / #GridCells / #HeadDirectionCells / #SplitterCells … (give me more)

And then we have the brain regions:

.#Hippocampus / #Striatum / #RetrosplenialCortex / #Cortex / #Cerebellum / …

Bonus:
.# NeuroBuzz: once a post takes off, anyone can add it as an answer and then the author can edit it in the original post (but don’t add it when writing the original post, that’s cheating)

@cyrilpedia lol, that other article seems very interesting though!
#GridCells

#barbaraTversky #spacecells #gridcells #memory #cognitivepsychology
https://www.samharris.org/podcasts/making-sense-episodes/168-mind-space-motion

New #NeuroPreprint
Simultaneous representation of multiple time horizons by entorhinal grid cells and CA1 place cells

Chaudhuri-Vayalambrone, Rule et al., 2023

#PlaceCells #GridCells #ProspectiveCoding #Hippocampus #MedialEntorhinalCortex
… so many papers these days…!!

In case this is useful for anyone out here - new tools for Bayesian analysis of grid cell activity (with the benefits of efficiently evaluating covariates and avoiding binning): https://arxiv.org/abs/2303.17217

#neuroscience #entorhinalcortex #gridcells

@TrackingActions Excellent dispatch! Let's tag with #neuroscience #GridCells #hippocampus so it appears on those who follow this tags, and also becomes easier to find in the future.

New review on the “spatial cells” across different species! Looks very interesting:
Neural mechanisms for spatial cognition across vertebrates
Vinepinsky & Segev 2023

Small but important comment: it is perfectly normal for place cells to have multiple #PlaceFields ! Only in very small environments (<80cm diameter) will you mostly see single-field place cells. The single field is probably more the exception than the rule in the natural world.

#NeuroPaper #Review #Neuroscience #PlaceCells #HeadDirectionCells #GridCells #BVCs #CrossSpecies

Evolutionary “tree” showing which types of species hold which types of spatial cells
Interestingly, so far, it seems grid cells have been found only in mammals… but they are quite hard to find so it could just be that more attempts in non-mammals are needed.

⤵️4/5 Why P2 ‘Grid cells in a 3D lattice’:

Wireless recordings of 2D-verified #GridCells, in 3D!
Rats climb around for >1h while foraging for paste (for in-depth analysis of behaviour, see: https://link.springer.com/article/10.1007/s10071-020-01432-w)
Grid cells, although spatially stable, do not have 3D grid patterns! Just randomly-distributed fields.
This disagrees with many model predictions!
Head-direction coding is preserved in 3D!

https://www.nature.com/articles/s41593-021-00907-4

Photo of the 3d lattice maze used in the experiment, elevated, made of red plastic bars. Note the multiple tracking cameras on the ceiling. Photo by Roddy Grieves.

Photo of a rat preparing to go down a level in the lattice maze, his hind legs firmly anchored in the first level, his front paws ready to catch the bar in the lower level. (very impressive) photo by Roddy Grieves.

Example recorded grid cells spike plots and rate maps, of different grid scales, in the 2D arena (to detect grid cells) and in the 3D lattice. The cells have very nice and regular activity fields in the 2D arena, but they generally have randomly-distributed fields in 3D.
Note that this shows one of the rare examples of a rather columnar 3D grid cells, showing a projected grid pattern on the x,y plane (this is an exception).

Plots showing the existence and stability of directional coding between 2D and 3D environments, of #HeadDirection cells recorded in the medial entorhinal cortex together with the grid cells.

Verschiedene Zelltypen im Gehirn helfen uns bei der räumlichen Orientierung. Sie erstellen mentale Karten, die die räumliche Geometrie der Außenwelt repräsentieren.
Infografik: Das innere Navigationssystem

@nadel Another amazing episode! So clearly written and interesting. Thank you so much again for sharing.
Adding some hashtags to help this gem being discovered:

#HippocampusGurus #HippocampusHistory #hippocampus #PlaceCells #EntorhinalCortex #GridCells

#arxivfeed :

"A Topological Deep Learning Framework for Neural Spike Decoding"
https://arxiv.org/abs/2212.05037

#Neuroscience #Neuro #Brain #MachineLearning #DeepLearning #FeatureExtraction #SpikeTrains #GridCells #HeadDirectionCells

#GridCells

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