@adredish @WorldImagining @elduvelle @tyrell_turing @tdverstynen
This paper was just published:
Cross-strata co-occurrence of ripples with theta-frequency oscillations in the hippocampus of foraging rats
P. Seenivasan, R. Basak and R. Narayanan
https://doi.org/10.1113/JP284629
They defined ripple events as 2 sd above mean in 120-250 Hz band

@PessoaBrain it’s also worth noting that human neuroscience has mostly ignored thalamus for a variety of technical reasons, and instead focus on theories about localization of function in the cortical mantle. There is of course lots of progress in labs outside my narrow statement above but the statement holds as the foundation of much of human brain cognitive work. This needs to change (same goes for animal folks the focus on cognitive centers of the brain).

@manisha thank you for letting me know about the "unlisted" classification, this is very useful information.
Good you tagged @RhythmicSpikesAJ - I even follow her here on here it seems!

Just uploaded a dataset to Zenodo:
"Extracellular recordings and juxtacellular labelling with glass electrodes in the mouse medial septum and hippocampus"
https://zenodo.org/record/8187903

These are the original recordings from the following publications:
Joshi et al Neuron 2017 (https://doi.org/10.1016/j.neuron.2017.10.033)
Viney et al eLife 2018 (https://doi.org/10.7554/elife.34395)
Salib et al J Neurosci 2019 (https://doi.org/10.1523/jneurosci.3024-18.2019)

We used glass electrodes to simultaneously record local field potentials in the pyramidal cell layer of dorsal CA1 of the #hippocampus and the #medialseptum along with single medial septal cells. At the end of each recording we entrained the cell to current pulses (modulation) using the juxtacellular labelling technique. This delivered neurobiotin into the recorded cell for subsequent recovery in #brain sections.

Data may be of interest to people investigating hippocampal network #oscillations (theta, gamma, ripples) and #spike timing.

***New preprint alert***
"Pathway-specific progression of Tau pathology in the human thalamus"
We discovered that large presynaptic terminals containing vGLUT2 preferentially accumulate paired helical filaments of #Tau in the anterodorsal nucleus of the #thalamus, even at the stage before #Alzheimer’s disease.
But we could not detect them in the small corticothalamic terminals, suggesting Tau is not spreading anterogradely from the #cortex.
We also detected pathological Tau in both presynaptic and postsynaptic sites, which suggests Tau crosses specific #synapses.
Adjacent thalamic nuclei such as the anteroventral and mediodorsal were relatively resistant to Tau #pathology.
We suggest there is a 'hidden' #subcortical route for the spread of Tau in the ageing human #brain.
Since the anterodorsal thalamic nucleus is so vulnerable, and contains high densities of #neurons that are sensitive to head direction and gravity, it may explain the very early deficits in spatial orientation in people that go on to develop Alzheimer’s disease.
Please see our #preprint for further details:
https://www.biorxiv.org/content/10.1101/2023.06.05.543738v1

@WorldImagining @adredish @elduvelle @tyrell_turing @tdverstynen

No task or virtual environment, and no dietary restrictions. Spontaneous running and resting on a frisbee.

Also have other datasets in virtual environment (linear track) but not looked carefully

@WorldImagining @elduvelle @tyrell_turing @tdverstynen

One of the complexities is whether SWRs can occur in the middle of theta. Personally, I have never seen anything that I would call an SWR in theta. But Csicsvari has argued that SWRs also occur in the middle of theta. (Jozsef has said as much at his posters in SFN meetings in the past. I don't know what his current take is.) Loren Frank has argued that SWRs and theta cycles are two edges of a continuum. (Loren has said this in person - I don't know if he's said it in print and I don't know what his current belief is.)

My current belief is that these are very different processes, that SWRs do not occur during theta, and that people often mislabel high-gamma (140-180 Hz) signals that do occur in theta cycles as SWRs because they stretch their SWR bandwidths too low.

Note: belief = best story so far (belief in a Bayesian sense. :)

@adredish @WorldImagining @elduvelle @tyrell_turing @tdverstynen

If I may add a comment here. In head-restrained mice, I have not observed ripples during movement-related theta cycles (defined as having a similar amplitude and frequency as ripples during recent periods of immobility). Gamma cycles are different.

However, if the mouse pauses during a movement period, theta can be transiently disrupted and a small sharp wave and ripple can occur. This is different to ripples occurring during actual theta cycles but could be misinterpreted as occuring within a theta epoch.

I have recorded REM theta less often in mice but do not recall observing ripples during these higher amplitude theta cycles either.

Isolated ripple-like events can take place infrequently during continuous theta in CA1 of urethane-anaesthetised rats with supplemental ketamine and xylazine followed by tail pinch.

Observations based on hundreds of hours of glass electrode recordings mostly in mice

Should we conclude that heavily time constrained peer review and editorial decisions are a poor way to select the best science, Nature?

https://www.nature.com/articles/d41586-023-00056-7

Hidden Phenomenal Differences. I REALLY like this very short paper.

https://psyarxiv.com/yfb3h

It resonates with many things I discovered only very gradually about my own subjective experiences, and (correspondingly) with the increasing sense that conscious experiences of all kinds must be much more varied than we typically hypothesize when studying "the" mind and "the" brain.

#Introduction
Hi all, I'm finally introducing myself in this new year of 2023! I am a postdoctoral researcher doing #neuroscience, often with a theoretical angle. My own work tends to focus on neural network dynamics, network architecture and (pre)motor control, but my interests are broad and I am trying to use Mastodon to broaden them even more! I also have a special interest in sociology, especially the sociology of #academia. I'm looking forward to learning from the other users, and to communicating about my own research!

Mistlecytes in the human #brain?

Aging-related tau astrogliopathy (ARTAG) refers to Tau #pathology associated with #astrocytes in aged humans. #Mistletoe is a parasitic plant often found in trees.

The AT8 antibody is commonly used to label phosphorylated (pSer202/Thr205) Tau. We have started referring to some of the AT8-immunoreactive astrocytes in our human brain samples as 'mistlecytes'. Do you see the resemblance?

But do they contribute to any kind of pathology or impairment, or are they simply part of 'normal' ageing? A good review about ARTAG can be found here: https://doi.org/10.1007/s00401-015-1509-x

#introduction
I am a Professor of neuronal networks at Karolinska Institutet, Stockholm, Sweden. My lab studies the structure and function of the mouse prefrontal cortex. I have a keen interest in inhibitory interneurons and cortical oscillations

#reintroduction #migration

👋

I do #NeuroScience and am interested in the #Circuit dynamics of adaptive but reliable visually guided #Behavior.

In our group at the University of #Bonn, we study

- the stabilization of the neural code in #Vision, #Perception, #Learning, and #Memory

- the pathway-specific processing of #Sensory and #SelfMotion signals

We emphasize ethologically relevant behavior, longitudinal #Optophysiology, and miniaturized and benchtop #TwoPhoton microscopy.

www.troselab.de

🫡

New #introduction for neuromatch.social 🙂​

My group investigates and defines cell types and neural circuits of the #thalamus, #hippocampus, and #cortex that contribute to spatial #memory processes.
These processes break down in #Alzheimer's disease. To understand the causes/triggers of #neurodegeneration, we study early-stage #Tau #pathology in the human #brain and in mouse models.

I previously defined various types of retinal ganglion cells using ex vivo #patchclamp recordings during my PhD in #Basel, before moving to #Oxford to work on #GABAergic #neurons of the #hippocampus, followed by the #medialseptum. My favourite technique is in vivo #extracellular recordings and #juxtacellular labelling as it enables identification of single #cells based on their firing patterns, #axon terminal distribution, and #neurochemical profile.

As an #experimentalist, my expertise is primarily in vivo #neurophysiology and #neuroanatomy. I am also interested in #consciousness, the origins of #memory, and regulation of #neuronal activity and #behaviour by #neuropeptides.