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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Also, another shout out to @helenlailab.bsky.social for a great collaboration and the BRAIN Initiative's Cell Atlas Network and BICAN Spinal Cord working group for funding and critical input (16/15).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Clarification: Kania lab beautifully characterized the Phox2a lineage ascending projection neurons and Todd lab demonstrated transcriptomic diversity and differential sensory engagement of Phox2a SPN subtypes.

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Huge shout out to the study lead authors Liliana Cano-Gomez, Helen Poldsam and Satoshi Ishishita, who figured it all out (15/15).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Finally – we proposed cell-type-to-phenotype maps as a means to functionally annotate some of the SPN diversity. Below we are showing combinations of SPNs yielding either a pain/itch/touch or temperature phenotype (14/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

We ended up generating a molecular anatomic catalog of SPNs, as well as a wiring matrix, contextualized existing SPN markers and satisfyingly recapitulated most of the previously characterized transcriptomic SPN types (e.g. Phox2a lineage SPN types first characterized by the Todd lab) (13/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

… and ended up finding that 78 out of the 500+ neuron types link the spinal cord to higher order brain centers. We found both rostro-caudally specialized as well as invariant SPNs. Importantly, again the granular resolution enabled us to separate SPNs from much more abundant interneurons (12/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

We were particularly curious about which of these transcriptomic neuron types constitute the ascending projection neuron repertoire so we performed Xenium based cell-type-resolved multiplexed retrograde tracing (11/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

However, granular neuron type level analysis reveals sex specific cholinergic visceral motor neurons as well as glutamatergic neurons mostly in the thoracic/sacral spinal cord (10/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Some examples: at the crude transcriptomic neuron type level there is no sexual dimorphism to be observed despite the fact that spinal cord orchestrates many sexually dimorphic sensory-motor/autonomic functions (9/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Long story short: we need to analyze spinal neural diversity at an order of magnitude higher granularity (i.e. neuron types, not transcriptomic groups) to capture things such as sex specific neuron types and ascending projection neurons (8/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

You can check out the bewildering molecular, anatomic and projectomic cellular diversity of the mouse spinal cord here in our interactive atlas (7/n): spinal-cord-explorer.shinyapps.io/mouse/

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

We can do a crude analysis clustering neurons into ~58 transcriptomic groups OR go deeper and find more than 500+ anatomically and transcriptomically distinct neuron types (6/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

However, how granularly do we need to analyze the data to capture functionally relevant units in the spinal cord (5/n)?

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

So we took a two-pronged approach profiling full rosto-caudal mouse SC neural diversity with intact tissue spatial transcriptomics (Xenium) as well as multiomics (snRNA-seq/snATAC-seq) profiling north of 2 million cells and 750k> neurons (4/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

We suspected that perhaps we might be missing key cellular players in SC atlases due to limited cellular sampling or cell fallout due to tissue dissociation artifacts. (3/n)

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

We were puzzled by the broadly varying estimates of mammalian spinal cord (SC) neural diversity and by the apparent difficulty in locating known cellular entities and functions (e.g. ascending projection neurons, sex specific neuronal real estate etc.) in existing atlases (2/n).

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Allan-Hermann Pool @allanhpool.bsky.social · 22/06/2026

Thrilled to share the latest pre-print from the lab – TLDR: we identified the (near) full ascending spinal projection neuron repertoire that gives rise to central itch/touch/pain/temperature sensation as well as sex specific neuron types in the mouse spinal cord. Thread below (1/n):

biorxiv.org

Deep Cellular and Spatial Profiling of the Mouse Spinal Cord Reveals Sex-Specific Neuron Types and the Ascending Projection Neuron Repertoire

The spinal cord gives rise to central somatosensation and orchestrates autonomic and motor control. How its cellular diversity achieves functions across sex, longitudinal axis and links the spinal cor...

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Reposted by Allan-Hermann Pool

allen institute @alleninstitute.org · 19/11/2025

Spinal cell types are intensely studied yet poorly understood. TOMORROW at #SfN25 - Join us for a minisymposium on efforts to characterize & annotate spinal cellular diversity & therapeutically address spinal neural classes. 📲 www.abstractsonline.com/pp8/#!/2117…

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Allan-Hermann Pool @allanhpool.bsky.social · 18/11/2025

Swing by the @allanhpool.bsky.social lab posters this morning. Satoshi Ishishita and Liliana Cano Gomez are sharing our latest work on characterizing and dissecting the spinal cord ascending projectome.

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Allan-Hermann Pool @allanhpool.bsky.social · 17/11/2025

Finally - it was an absolute pleasure to co-organize this with Trygve Bakken from the Allen Institute!

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Allan-Hermann Pool @allanhpool.bsky.social · 17/11/2025

Looking forward to your talks: Michael J. Leone, Trygve Bakken, Denise Ramirez, Cindy van Velthoven and Myung Chul (Sam) Noh!

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Allan-Hermann Pool @allanhpool.bsky.social · 17/11/2025

We have a great line-up of speakers from the @alleninstitute.org , @rpseal.bsky.social and Andreas Pfenning's labs and UTSW reporting the latest updates from the Brain Initiative BICAN network and beyond.

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Allan-Hermann Pool @allanhpool.bsky.social · 17/11/2025

Join us on Wednesday afternoon for an @sfn.org minisymposium on the Cellular Structure of the Spinal Cord. We have updates from cell-type annotation and new anatomical atlases, to cell-type resolved projectomes, pan-mammalian nomenclatures and emerging cell-type targeted therapeutic avenues.

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Allan-Hermann Pool @allanhpool.bsky.social · 07/11/2025

Special shoutout to Satoshi Ishishita and Helen Poldsam from the Pool lab for their contributions.

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Allan-Hermann Pool @allanhpool.bsky.social · 07/11/2025

Exciting collaboration with @tedpricethepainguy.bsky.social lab and lead authors Katherin Gabriel and @oliviadavis.bsky.social! First description of sexually dimorphic glial cell classes in the human spinal cord, deep dive into genes driving cross-species cellular differences and much more.

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Allan-Hermann Pool @allanhpool.bsky.social · 23/06/2025

Thank you, Sebastian! Indeed, we have nice critical mass in Dallas.

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Allan-Hermann Pool @allanhpool.bsky.social · 20/06/2025

Thrilled to join the Rita Allen Scholars community (ritaallen.org/stories/2025...) and grateful for the support! Glad to (re)discover many inspirational colleagues as current and former award in pain scholars.

ritaallen.org

Announcing The 2025 Rita Allen Foundation Scholars - Rita Allen Foundation

Investing in transformative ideas in their earliest stages to promote breakthrough solutions to significant problems

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