William M. McCallum

Reward-driven emergence of auditory pattern encoding in the primate motor system The ability to anticipate rhythmic patterns is fundamental to human experience, enabling music appreciation, speech comprehension, and dancing in sync to music. How the brain learns to use acoustic information to guide motor behavior remains a key question whose neural underpinnings and evolutionary origins are debated, especially in non-human primates. To understand how brain areas involved in motor control naively respond to predictable tone patterns, we recorded large single neuron populations across primary somatosensory (S1), primary motor (M1), dorsal premotor (PMd), supplementary motor (SMA), pre-supplementary motor (preSMA) cortices, globus pallidus interna (GPi), and medial geniculate body (MGB) of a rhesus monkey. During passive listening (Experiment 1) with a reward only at the end of each trial, primarily the MGB, not motor areas, responded to the auditory tone patterns, ruling out the spontaneous entrainment of motor activity to auditory patterns. Almost all areas robustly

While humans spontaneously dance to a beat, the evolutionary origins of this ability remain debated. Behavioral work has shown that primates can move to auditory rhythms after training.

Our question was: How does this association emerge in the brain?

www.biorxiv.org/content/10....

Our latest preprint. More evidence that diabetic neuropathy is a neuro degenerative disease. Very proud of @ish1789.bsky.social and our whole PRECISION group who made this work possible. #HEALinitiative funded

Ontogeny of the spinal cord dorsal horn The dorsal horn of the mammalian spinal cord is organized into laminae where each layer is populated by different neuron types, has distinctive circuit connections, and plays specialized roles in beha...

Excited to share @rbrianroome.bsky.social ‘s beautiful paper on development of the dorsal horn of the mouse spinal cord @science.org

This is how the anatomical organization and cell types that process pain, touch, body position and more are laid down.

www.science.org/doi/10.1126/...

How do neural circuits generate the walking rhythm?

Using connectome simulations, @sarahpugly.bsky.social found a minimal central pattern generator (CPG) that produces oscillations in leg motor neurons. Same circuit motif for each 🪰 leg.

w @bingbrunton.bsky.social

www.biorxiv.org/content/10.1...

As funding falters, young brain scientists rethink careers in research Research on brain disorders may slow as young neuroscientists struggle to find jobs and research grants.

Research on brain disorders may slow as young neuroscientists struggle to find jobs and research grants. n.pr/4pgmAna

And here is the story after peer review. This work highlights our current approach, which is to use Piezo channels to uncover new areas of biology that are shaped by mechanical forces: www.science.org/doi/10.1126/...

A table showing profit margins of major publishers. A snippet of text related to this table is below. 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year.

A figure detailing the drain on researcher time. 1. The four-fold drain 1.2 Time The number of papers published each year is growing faster than the scientific workforce, with the number of papers per researcher almost doubling between 1996 and 2022 (Figure 1A). This reflects the fact that publishers’ commercial desire to publish (sell) more material has aligned well with the competitive prestige culture in which publications help secure jobs, grants, promotions, and awards. To the extent that this growth is driven by a pressure for profit, rather than scholarly imperatives, it distorts the way researchers spend their time. The publishing system depends on unpaid reviewer labour, estimated to be over 130 million unpaid hours annually in 2020 alone (9). Researchers have complained about the demands of peer-review for decades, but the scale of the problem is now worse, with editors reporting widespread difficulties recruiting reviewers. The growth in publications involves not only the authors’ time, but that of academic editors and reviewers who are dealing with so many review demands. Even more seriously, the imperative to produce ever more articles reshapes the nature of scientific inquiry. Evidence across multiple fields shows that more papers result in ‘ossification’, not new ideas (10). It may seem paradoxical that more papers can slow progress until one considers how it affects researchers’ time. While rewards remain tied to volume, prestige, and impact of publications, researchers will be nudged away from riskier, local, interdisciplinary, and long-term work. The result is a treadmill of constant activity with limited progress whereas core scholarly practices – such as reading, reflecting and engaging with others’ contributions – is de-prioritized. What looks like productivity often masks intellectual exhaustion built on a demoralizing, narrowing scientific vision.

A table of profit margins across industries. The section of text related to this table is below: 1. The four-fold drain 1.1 Money Currently, academic publishing is dominated by profit-oriented, multinational companies for whom scientific knowledge is a commodity to be sold back to the academic community who created it. The dominant four are Elsevier, Springer Nature, Wiley and Taylor & Francis, which collectively generated over US$7.1 billion in revenue from journal publishing in 2024 alone, and over US$12 billion in profits between 2019 and 2024 (Table 1A). Their profit margins have always been over 30% in the last five years, and for the largest publisher (Elsevier) always over 37%. Against many comparators, across many sectors, scientific publishing is one of the most consistently profitable industries (Table S1). These financial arrangements make a substantial difference to science budgets. In 2024, 46% of Elsevier revenues and 53% of Taylor & Francis revenues were generated in North America, meaning that North American researchers were charged over US$2.27 billion by just two for-profit publishers. The Canadian research councils and the US National Science Foundation were allocated US$9.3 billion in that year.

The costs of inaction are plain: wasted public funds, lost researcher time, compromised scientific integrity and eroded public trust. Today, the system rewards commercial publishers first, and science second. Without bold action from the funders we risk continuing to pour resources into a system that prioritizes profit over the advancement of scientific knowledge.

We wrote the Strain on scientific publishing to highlight the problems of time & trust. With a fantastic group of co-authors, we present The Drain of Scientific Publishing:

a 🧵 1/n

Drain: arxiv.org/abs/2511.04820
Strain: direct.mit.edu/qss/article/...
Oligopoly: direct.mit.edu/qss/article/...

Neural manifolds that orchestrate walking and stopping https://www.biorxiv.org/content/10.1101/2025.11.08.687367v1

A Reference Atlas of the Human Dorsal Root Ganglion Somatosensory perception largely emerges from diverse peripheral sensory neurons whose cell bodies reside in dorsal root ganglia (DRG). Damage or dysfunction of DRG neurons is a major cause of chronic...

The BIG DRG paper is now up on @biorxiv-neursci.bsky.social www.biorxiv.org/content/10.1... so many people worked so hard to make this happen. Props to the whole PRECISION Human Pain Network.

Whole-cortex in situ sequencing reveals input-dependent area identity - Nature BARseq interrogates the expression of 104 cell-type marker genes in 10.3 million cells over nine mouse forebrain hemispheres to reveal the role of peripheral inputs on cortical area development.

Still think brain regions don’t exist? That everything is everywhere? That cell types don’t matter and that everything is a dynamical phase portrait?

Wrong.

Interconnected brain modules exist at the level of fine grained transcriptomics. www.nature.com/articles/s41...

Sensory expectations shape neural population dynamics in motor circuits Nature - Experiments with human volunteers and macaques show that expectations produced by probabilistic cueing of future sensory inputs shape motor circuit dynamics in order to increase the...

Thrilled that our paper is out today in Nature!
www.nature.com/articles/s4...

🧠🌟🐭 Excited to share some of my postdoc work on the evolution of dexterity!

We compared deer mice evolved in forest vs prairie habitats. We found that forest mice have:
(1) more corticospinal neurons (CSNs)
(2) better hand dexterity
(3) more dexterous climbing, which is linked to CSN number🧵

Evolutionary expansion of the corticospinal system is linked to dexterity in Peromyscus mice https://www.biorxiv.org/content/10.1101/2025.10.16.682851v1

New questions around motor neurons and plasticity A researcher’s theory hangs muscle degeneration on a broken neural circuit.

Results showed it was possible to “effectively rescue motor neuron function,” and George Mentis and his team think their results are coalescing into a theory, even if they don’t fully understand it yet.

By David Adam

#neuroskyence

www.thetransmitter.org/neurodegener...

Labelled axons of calb1+ spinal projection neurons innervate multiple brain targets associated with cold sensation and thermoregulation. Darkfield images of different brain areas including the postal parabrachial and periaqueductal grey are shown with axons of ascending cells in yellow.

New preprint from the spinal cord group at Glasgow. Anatomical and functional characterisation of spinal circuits for cold, from sensory neurons to the brain…..https://www.biorxiv.org/content/10.1101/2025.10.03.680240v1

My department at Emory is a hiring a tenure-track neuroscientist!

Anyone who's talked to me in the last 4 years knows I cannot say enough good things about my dept and the neuroscience community here. My colleagues are so wonderfully supportive. Postdocs, please apply!

apply.interfolio.com/174371

A neural geometry for forelimb proprioception in the cervical spinal cord https://www.biorxiv.org/content/10.1101/2025.09.26.678887v1

New preprint out from the lab. We identified three critical windows over which sensorimotor behaviours can be shaped. Altered early experience over these windows changes somatosensory and motor outcomes for life. Tour de force experiments by Laura Andreoli. @medresfdn.bsky.social @uclnpp.bsky.social

A neural entero-pancreatic pathway that regulatesinsulin secretion and glucose tolerance https://www.biorxiv.org/content/10.1101/2025.08.14.670343v1

Differential kinematic coding in sensorimotor striatum across behavioral domains reflects different contributions to movement - Nature Neuroscience Hardcastle and Marshall et al. show that striatal function is domain specific, required for task-related but not spontaneously expressed movements. This functional distinction is reflected in starkly ...

Excited to announce that my first postdoc paper is now online!

Links:
www.nature.com/articles/s41...
rdcu.be/eAcN7

In it, we examine the perennial question: what changes in the brain when learning a new motor skill?

Read more below to find out 👇

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How do neural dynamics in motor cortex interact with those in subcortical networks to flexibly control movement? I’m beyond thrilled to share our work on this problem, led by Eric Kirk @eric-kirk.bsky.social with help from Kangjia Cai!
www.biorxiv.org/content/10.1...

The American people were lied to about Vietnam, with tragic consequences.

The American people were lied to about Iraq, with tragic consequences.

The American people are being lied to again today. We cannot allow history to repeat itself.

Cephalopods, vision’s next frontier For decades, scientists have been teased by the strange but inaccessible cephalopod visual system. Now, thanks to a technological breakthrough from a lab in Oregon, data are finally coming straight…

The octopus brain has teased researchers since the 1960s, but recording from it seemed impossible. Cris Niell and his team’s calcium imaging experiments finally “showed that this brain could be studied,” says Sam Reiter.

By @callimcflurry.bsky.social

www.thetransmitter.org/vision/cepha...

New preprint out! We developed a behavioural platform for the kinematic analysis of skilled whole body behaviour. Very fun collaboration with Christopher Black, @liamebrowne.bsky.social and Rob Brownstone.

Why we study shrimp on treadmills: The case for curiosity-driven research “If we cut or limit funding for curiosity-driven research, we risk shutting down the pipeline of future innovation,” writes Carole LaBonne of Northwestern.

My ode to Curiosity Driven Research

www.statnews.com/2025/04/03/b...

Uranus emits more heat than previously thought Uranus radiates more energy than it gets from the sun, two new studies find — just as Jupiter, Saturn and Neptune do.

New observations from space- and ground-based telescopes reveal that Uranus radiates more energy than sunlight provides, two research teams report in work submitted to arXiv.org in late February.

I am very proud to announce that my PhD paper finally came out in Cell! In this *very* collaborative study, we develop and release a deep-learning approach to predict neuron type identity from their electrical signature. doi.org/10.1016/j.ce... 1/16 🧵

My cat Lulu us here for us all

We were able to get a clip of the video to upload from the "turtle dance" research paper. 🧪

This is figure 4, which shows sensory analysis evaluation.

A paper in Communications Engineering presents a new method to optimally cook both the yolk and white of a boiled chicken egg. "Periodic cooking” yields an evenly-cooked egg with a higher nutritional content than shell-on eggs cooked by conventional methods. https://go.nature.com/4hJWNzU 🧪