Markus Meister
@mameister4.bsky.social
Neuroscientist. Long-form opinions at https://markusmeister.com.
On the other hand, see this interesting null report about psilocybin effects in mice: www.biorxiv.org/content/10.1...
A multi-institutional investigation of psilocybin’s effects on mouse behavior
Studies reporting novel therapeutic effects of psychedelic drugs are rapidly emerging. However, the reproducibility and reliability of these findings could remain uncertain for years. Here, we impleme...
www.biorxiv.org
December 5, 2025 at 9:27 PM
On the other hand, see this interesting null report about psilocybin effects in mice: www.biorxiv.org/content/10.1...
When I was little, and wondering whether to study physics, his book Physics in the Twentieth Century made a big impression. Still a good read today.
November 30, 2025 at 10:31 PM
When I was little, and wondering whether to study physics, his book Physics in the Twentieth Century made a big impression. Still a good read today.
But maybe not 10 years ago? A while ago I rediscovered a thing, and found it had been discovered every 25 years, going back all the way to Lord Adrian. Come to think of it, it’s time again now… pubmed.ncbi.nlm.nih.gov/9535954/
Synchronous period-doubling in flicker vision of salamander and man - PubMed
Periodic flashes of light have long served to probe the temporal properties of the visual system. Here we show that during rapid flicker of high contrast and intensity the eye reports to the brain only every other flash of light. In this regime, retinal ganglion cells of the salamander fire spikes o …
pubmed.ncbi.nlm.nih.gov
November 30, 2025 at 4:30 AM
But maybe not 10 years ago? A while ago I rediscovered a thing, and found it had been discovered every 25 years, going back all the way to Lord Adrian. Come to think of it, it’s time again now… pubmed.ncbi.nlm.nih.gov/9535954/
It’s a rare neuroscience paper that makes a claim that could be proven wrong, even in principle.
November 30, 2025 at 4:19 AM
It’s a rare neuroscience paper that makes a claim that could be proven wrong, even in principle.
Do you mean papers in Science magazine? I would guess 90% or so. But it's an unfair question, because being right isn't part of their editorial goals. See, for example, Peter Stern in this interview: www.scribd.com/document/382...
Stern 1-2007 | PDF | Experiment | Science
The document discusses an interview with Peter Stern, an editor at Science magazine. It covers topics like the submission and review process, changes over Stern's 10 years as an editor, popular fields...
www.scribd.com
November 29, 2025 at 8:31 PM
Do you mean papers in Science magazine? I would guess 90% or so. But it's an unfair question, because being right isn't part of their editorial goals. See, for example, Peter Stern in this interview: www.scribd.com/document/382...
Imagine showing a Patek-Philippe to someone who had only known an Apple watch. Eventually combustion vehicles will have that same old-timey precision-engineering appeal.
November 29, 2025 at 7:11 PM
Imagine showing a Patek-Philippe to someone who had only known an Apple watch. Eventually combustion vehicles will have that same old-timey precision-engineering appeal.
And - helpfully - many authors just call them P-cells and M-cells.
November 29, 2025 at 6:32 PM
And - helpfully - many authors just call them P-cells and M-cells.
Also: Parasol ganglion cells start the Magno pathway, while Midget cells start the Parvo pathway.
November 28, 2025 at 9:49 PM
Also: Parasol ganglion cells start the Magno pathway, while Midget cells start the Parvo pathway.
I know because I discovered them.
pubmed.ncbi.nlm.nih.gov/2035024/
They are based on conventional synaptic transmission. And fortunately they stop once the retina has to do something useful, like seeing.
pubmed.ncbi.nlm.nih.gov/2035024/
They are based on conventional synaptic transmission. And fortunately they stop once the retina has to do something useful, like seeing.
Synchronous bursts of action potentials in ganglion cells of the developing mammalian retina - PubMed
The development of orderly connections in the mammalian visual system depends on action potentials in the optic nerve fibers, even before the retina receives visual input. In particular, it has been suggested that correlated firing of retinal ganglion cells in the same eye directs the segregation of …
pubmed.ncbi.nlm.nih.gov
November 24, 2025 at 4:23 PM
I know because I discovered them.
pubmed.ncbi.nlm.nih.gov/2035024/
They are based on conventional synaptic transmission. And fortunately they stop once the retina has to do something useful, like seeing.
pubmed.ncbi.nlm.nih.gov/2035024/
They are based on conventional synaptic transmission. And fortunately they stop once the retina has to do something useful, like seeing.
I so miss Bob! Any chance for early parole?
November 24, 2025 at 3:50 AM
I so miss Bob! Any chance for early parole?
Footnote: The retina does contain an "ephaptic synapse" between horizontal cell and cone terminal. The HC injects current into the synaptic cleft that alters the potential across V-dep channels in the cone. The tight geometry constrains the interaction to just those two neurons. Cool biophysics! 8/8
November 24, 2025 at 12:23 AM
Footnote: The retina does contain an "ephaptic synapse" between horizontal cell and cone terminal. The HC injects current into the synaptic cleft that alters the potential across V-dep channels in the cone. The tight geometry constrains the interaction to just those two neurons. Cool biophysics! 8/8
At the other end of the nervous system, the waves and oscillations then hand control back to the spiking motorneurons so they can make the muscles twitch. Like I said: conceivable, but I wouldn't bet on that picture. 7/8
November 24, 2025 at 12:23 AM
At the other end of the nervous system, the waves and oscillations then hand control back to the spiking motorneurons so they can make the muscles twitch. Like I said: conceivable, but I wouldn't bet on that picture. 7/8
It is conceivable that somewhere on the route from sensory periphery to central brain regions, the spiking neurons hand over the reins to coarse waves and oscillations, and those become dominant and implement cognition. 6/8
November 24, 2025 at 12:23 AM
It is conceivable that somewhere on the route from sensory periphery to central brain regions, the spiking neurons hand over the reins to coarse waves and oscillations, and those become dominant and implement cognition. 6/8
So in the periphery, our models of circuit function are quite powerful at explaining things and predicting function, and they don't need LFPs and oscillations. 5/8
November 24, 2025 at 12:23 AM
So in the periphery, our models of circuit function are quite powerful at explaining things and predicting function, and they don't need LFPs and oscillations. 5/8
A few years ago, Sergio Neuenschwander revisited this work and found that the oscillations were all an artifact of anesthesia. Incidentally, this was a courageous and hugely important thing to do. I'm not sure what the implications are for all the claims about cortical oscillations and binding. 4/8
November 24, 2025 at 12:23 AM
A few years ago, Sergio Neuenschwander revisited this work and found that the oscillations were all an artifact of anesthesia. Incidentally, this was a courageous and hugely important thing to do. I'm not sure what the implications are for all the claims about cortical oscillations and binding. 4/8
Local field potentials and oscillations are not part of that model of the retina [but see footnote]. There was a brief scare in the 1990s when Wolf Singer's group claimed that cortical oscillations were the solution to the binding problem, and that they traced all the way back to the retina. 3/8
November 24, 2025 at 12:23 AM
Local field potentials and oscillations are not part of that model of the retina [but see footnote]. There was a brief scare in the 1990s when Wolf Singer's group claimed that cortical oscillations were the solution to the binding problem, and that they traced all the way back to the retina. 3/8
For example, the retina. A pretty complex circuit, ~140 cell types, uses most of the neurotransmitters known to man, and performs some serious computations on its input. We have a useful model of how the circuit works, that can predict (to ~80%) the spiking output for a new visual stimulus. 2/8
November 24, 2025 at 12:23 AM
For example, the retina. A pretty complex circuit, ~140 cell types, uses most of the neurotransmitters known to man, and performs some serious computations on its input. We have a useful model of how the circuit works, that can predict (to ~80%) the spiking output for a new visual stimulus. 2/8
Of course ephaptic interactions exist, and so do low-dimensional waves and oscillations. But do we need to know? In the cases where we have actually understood something useful about the nervous system, did we need to invoke these phenomena? 1/8
November 24, 2025 at 12:23 AM
Of course ephaptic interactions exist, and so do low-dimensional waves and oscillations. But do we need to know? In the cases where we have actually understood something useful about the nervous system, did we need to invoke these phenomena? 1/8
Many people are frustrated by the lack of progress in understanding mechanisms of human cognition. To me, the answer is not "we've been thinking about neurons all wrong, throw out the conventional wisdom", and instead "we haven't been thinking hard enough using the things we already understand". 5/5
November 23, 2025 at 10:59 PM
Many people are frustrated by the lack of progress in understanding mechanisms of human cognition. To me, the answer is not "we've been thinking about neurons all wrong, throw out the conventional wisdom", and instead "we haven't been thinking hard enough using the things we already understand". 5/5
Nobel prizes have been given associated with this interaction. It plays a huge role in astrophysics. But almost nothing in chemistry depends on the spin interaction. If we had pretended that all interactions are equally important, our understanding of materials would be in a sorry state. 4/5
November 23, 2025 at 10:59 PM
Nobel prizes have been given associated with this interaction. It plays a huge role in astrophysics. But almost nothing in chemistry depends on the spin interaction. If we had pretended that all interactions are equally important, our understanding of materials would be in a sorry state. 4/5
Take an analogy to a system we actually understand: the hydrogen atom. Most of what it does can be understood from the potential between the charges on electron and proton. But if you look really carefully, you can also see a tiny interaction between the magnetic spins, about 1e6 times weaker. 3/5
November 23, 2025 at 10:59 PM
Take an analogy to a system we actually understand: the hydrogen atom. Most of what it does can be understood from the potential between the charges on electron and proton. But if you look really carefully, you can also see a tiny interaction between the magnetic spins, about 1e6 times weaker. 3/5
More seriously, we should not ignore extracellular fields and ephaptic coupling, but remember how weak they are compared to the other modes of neuronal coupling, and keep that in mind when thinking about brain function. 2/5
November 23, 2025 at 10:59 PM
More seriously, we should not ignore extracellular fields and ephaptic coupling, but remember how weak they are compared to the other modes of neuronal coupling, and keep that in mind when thinking about brain function. 2/5
Sure. We could also use crude technology (our ears) to listen to the computer under the desk. There's a hum. And oh! sometimes the hum changes frequency, and that seems to correlate with how hard the computer is working. Maybe computing is all about the hum? 1/5
November 23, 2025 at 10:59 PM
Sure. We could also use crude technology (our ears) to listen to the computer under the desk. There's a hum. And oh! sometimes the hum changes frequency, and that seems to correlate with how hard the computer is working. Maybe computing is all about the hum? 1/5
Nothing matters about a spike except the time when it happens. There quite literally is nothing else.
November 21, 2025 at 7:38 PM
Nothing matters about a spike except the time when it happens. There quite literally is nothing else.
3. Compared to the other interactions (chemical synapses, electrical synapses, neuromodulation) the LFP is exceedingly weak and low-dimensional.
4. So, if you model the CNS by successive approximation, you can safely ignore extracellular fields in your first few attempts.
2/2
4. So, if you model the CNS by successive approximation, you can safely ignore extracellular fields in your first few attempts.
2/2
November 21, 2025 at 3:51 PM
3. Compared to the other interactions (chemical synapses, electrical synapses, neuromodulation) the LFP is exceedingly weak and low-dimensional.
4. So, if you model the CNS by successive approximation, you can safely ignore extracellular fields in your first few attempts.
2/2
4. So, if you model the CNS by successive approximation, you can safely ignore extracellular fields in your first few attempts.
2/2