Ewan St. John Smith
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psalmotoxin.bsky.social
Ewan St. John Smith
@psalmotoxin.bsky.social
1.9K followers 1K following 1.2K posts
👨🏻‍🔬& 👨🏻‍🏫🏳️‍🌈Neuroscientist in Cambridge UK interested in the neurobiology of pain and everything to do with naked mole-rats. 🏃🏻‍♂️, 📖 & 🤘
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psalmotoxin.bsky.social
Excited to have joined the Editorial Board of @painresforum.bsky.social 😀

Sign up to painresearchforum.org's newsletter for regular updates regarding all things #PainResearch!

2026 will see the launch of PRF Journal Club and Webinar Series - watch this space!
Flyer for Pain Research Forum
December 1, 2025 at 8:00 AM
psalmotoxin.bsky.social
Beautifully crisp & sunny out this morning: 🏃🏻‍♂️ = ✅
Wintery trees surround a rippling pond under a dawn sky Wintery trees in the background, rippling pond under a bright blue sky Me recovering post-run
November 30, 2025 at 9:02 AM
psalmotoxin.bsky.social
Happy #Caturday 😺😺😺
Henry, black cat, lying on the cat tree Bertie, grey cat, stretching out on the carpet Matilda, white cat, standing under a chair
November 29, 2025 at 9:20 AM
psalmotoxin.bsky.social
Warmer out this morning, Friday short 🏃🏻‍♂️ = ✅
Me recovering post-run
November 28, 2025 at 7:08 AM
psalmotoxin.bsky.social
Crisp & sunny start to the day: 🏃🏻‍♂️ = ✅
Me recovering post-run
November 26, 2025 at 7:36 AM
psalmotoxin.bsky.social
Bleak, blustery, & a little damp, but 🏃🏻‍♂️ = ✅
Me halfway round under a grey sky
November 23, 2025 at 8:40 AM
psalmotoxin.bsky.social
Happy #Caturday 😺😺😺
Matilda, white cat, striding along a carpet Bertie, grey cat, striding along a carpet with Matilda, white cat, stranding scratcher in the background Henry, black cat, lying on the bed
November 22, 2025 at 8:28 AM
psalmotoxin.bsky.social
Bit later than anticipated, courtesy of a 4-hour transfer delay in Chicago, not much sleep = not much energy, but Friday short 🏃🏻‍♂️ = ✅
Me recovering post-run
November 21, 2025 at 6:03 PM
psalmotoxin.bsky.social
Great time at @sfn.org meeting, catching up with old friends & making new ones 😊

Great to have got positive feedback on our symposium & @interlukein.bsky.social / @mayadannawi.bsky.social had lots of interest in their posters 😃

✈️ tomorrow with lots of ideas...just got to get 💷 to support them!
Luke, Maya and me by SfN poster Luke presenting his poster Maya presenting her poster Me presenting
November 20, 2025 at 1:31 AM
psalmotoxin.bsky.social
At 13:00 our @phar.cam.ac.uk lab will be live @sfn.org!

Poster N3 sees @mayadannawi.bsky.social presenting on overexpression of Prdm12 in the adult sensory nervous system

Poster O6 sees @interlukein.bsky.social presenting on loss of Piezo2 in colonic sensory neurons with age

Please drop on by 😃
Maya with details of poster Luke with details of poster
November 19, 2025 at 3:56 PM
psalmotoxin.bsky.social
Last San Diego ☀️ 🏃🏻‍♂️ = ✅
Me halfway round run with San Diego Bay and bridge in the background
November 19, 2025 at 3:13 PM
psalmotoxin.bsky.social
San Diego sparkling in the sun & 🏃🏻‍♂️ = ✅
Me halfway round with San Diego Bay in the background
November 17, 2025 at 3:16 PM
psalmotoxin.bsky.social
Had a great time at our @sfn.org #PainResearch symposium yesterday, talks covering a whole range of pain states & roles of non-neuronal cells, review article for more reading: www.jneurosci.org/content/45/4... Thanks to @cherylstucky.bsky.social, @mdburton.bsky.social & Anne-Marie Heegaard!
Poster advertising our session Me, Cheryl, Anne-Marie and Michael giving talks Ewan, Anne-Marie, Cheryl and Michael having a much deserved post-symposium dinner!
November 16, 2025 at 6:58 PM
psalmotoxin.bsky.social
Interesting @sfn.org session kicking off: “What’s in a name? Define the boundaries of neuronal cell types”.

Introduced by @vabraira.bsky.social who provided a background on her name, engaging way to emphasise the importance of names. Talks from
Jeremy Miller & @tedpricethepainguy.bsky.social
Slide explaining background go Vic’s name Slide showing progress in techniques that has enabled new ways of naming neurons Jeremy and Ted listen on as Vic introduces the session
November 16, 2025 at 6:41 PM
psalmotoxin.bsky.social
Swapped wet & windy Cambridge for wet & windy (& warmer!) San Diego, which definitely has bigger boats than Cambridge 😅

Pre-symposium warm up 🏃🏻‍♂️ = ✅: if you’re at @sfn.org & want to know more about pain, come along this afternoon 👇
Me halfway round run with USS Midway in the background
November 15, 2025 at 3:40 PM
psalmotoxin.bsky.social
Very wet & windy this morning, & extra early start as 🚕, 🚊, 🚇, ✈️ & San Diego / @sfn.org await, but 🏃🏻‍♂️ = ✅
Me recovering post-run
November 14, 2025 at 6:38 AM
psalmotoxin.bsky.social
With the annual @sfn.org meeting coming up, I'm looking forward to Saturday's symposium with @cherylstucky.bsky.social , @mdburton.bsky.social & Anne-Marie Heegaard on non-neuronal cells in #PainResearch

Here's our accompanying review!
www.jneurosci.org/content/45/4...
Figure 1. Non-neuronal–neuron communication in the skin. (1) Non-neuronal cells and extracellular matrix in the skin. (2) When in ammatory events such as IL-6, ATP, and protease production from injury or infection are introduced, it causes an activation of cells, a disruption in extracellular matrix, and damage to sensory neurons. (3) During in ammatory cascades, injured or sensitized neurons potentiate pain and the development of a chronic pain state. Figure 2. Cell–cell interactions in joint pain. Numerous pathogenic changes occur within the OA joint and other musculoskeletal conditions that can contribute to pain, including cartilage degradation, synovitis, and bone remodeling (1). Within the joint evidence has established the role of some key non-neuronal cell types that contribute to pain (2) and some of the signaling nociceptor activation and sensitization mechanisms involved (3). There is also growing evidence for cell–cell interactions within the DRG that contribute to pain (4). See text for more details. Figure 3. Keratinocytes contribute to normal touch and chemotherapy-induced mechanical sensitivity through PIEZO1. Keratinocytes in the most super cial layer of the skin respond to mechanical forces via their expression of PIEZO1 channels and activated keratinocytes release ATP which signals to P2X4 channels on cutaneous sensory nerve endings. After a patient is treated with the chemotherapeutic paclitaxel, keratinocyte PIEZO1 is sensitized; the keratinocytes release more ATP and additional mediators, resulting in greater action potential signaling in sensory neurons that is sent to the spinal cord and brain through touch and pain pathways.
November 12, 2025 at 6:19 PM
psalmotoxin.bsky.social
Wet, windy, & lots of puddle hopping required, but 🏃🏻‍♂️ = ✅
Me recovering post-run
November 12, 2025 at 7:34 AM
psalmotoxin.bsky.social
Cool & sunny out this morning, great weather for 🏃🏻‍♂️ = ✅
Still lake reflects blue sky and trees Me halfway round with autumnal trees and river in background
November 9, 2025 at 9:03 AM
psalmotoxin.bsky.social
Slow start to this #Caturday 😺😺😺
Henry, black cat, laying on the cat tree Bertie, grey cat, dozing on the bed Matilda, white cat, lying half upside down on the floor
November 8, 2025 at 7:44 AM
psalmotoxin.bsky.social
Misty out round Cambridge this morning: Friday short 🏃🏻‍♂️ = ✅
Me recovering post-run
November 7, 2025 at 7:04 AM
psalmotoxin.bsky.social
Warm out this morning for early November + dead legs = not much fun, but 🏃🏻‍♂️ = ✅
Me recovering post-run
November 5, 2025 at 7:30 AM
psalmotoxin.bsky.social
Thus: Genetic/pharmacological modulation demonstrates GPR68’s role in acid-induced colonic nociception, supporting its therapeutic potential for pain management in colitis.
Thus: Genetic/pharmacological modulation demonstrates GPR68’s role in acid-induced colonic nociception, supporting its therapeutic potential for pain management in colitis.
November 4, 2025 at 4:49 PM
psalmotoxin.bsky.social
Lastly, we found that ogerin potentiated mechanical distension responses of the lumbar splanchnic nerve under acid, but not neutral conditions
(A) Schematic of experimental paradigm assessing the effects of the GPR68 PAM, Ogerin, (applied intraluminally) on colonic afferent responses to ramp distension. (B) Representative rate histograms and corresponding pressure traces from recordings showing afferent responses to ramp distensions 3-5 in pH 7.4, 6.8 and pH 6.8 + Ogerin (100 µM) groups. The dotted line highlights the sensitisation of afferent responses to distension in the pH 6.8 + Ogerin group. (C) Afferent response profiles of ramp distension 5 (0-80 mmHg) in pH 7.4 and pH 6.8 groups with and without Ogerin, normalised (norm.) to ramp distension 3 (*P < 0.05; two-way repeated measures ANOVA (main effect: P = 0.0493; F(3, 21) = 3.087) with Dunnett’s multiple comparisons test). Shaded area is SEM.
November 4, 2025 at 4:49 PM
psalmotoxin.bsky.social
Conversely, the positive allosteric modulate ogerin, but not ogerin negative control, ⇧ acid-induce lumbar splanchnic nerve firing in wildtype 🐭, but not in KO 🐭
The GPR68 PAM Ogerin potentiates colonic afferent responses to acid. (A) Schematic of the experimental paradigm assessing colonic afferent responses to bath application of pH 6.0 following treatment with the GPR68 positive allosteric modulator (PAM), Ogerin, or its inactive analogue ONC (Ogerin negative control). (B) Representative rate histograms of repeated afferent stimulation with pH 6.0. The 2nd response consisted of pretreatment with either Ogerin (top) or ONC (bottom). (C) Peak change in afferent activity of response 2 (post-drug application) normalised to response 1 (pre-drug application) for vehicle, ONC or Ogerin (in GPR68+/+ and GPR68-/- mice) treated groups (Ogerin vs ONC, P = 0.0005; Ogerin vs Vehicle, P = 0.0019; Ogerin vs GPR68-/-, P = 0.0002; one-way ANOVA (main effect: P = 0.0002; F(3, 18) = 11.36); with Dunnett’s multiple comparisons test; N = 5-6 animals per group). (D) AUC of response 2 (post-drug application) normalised to response 1 (pre-drug application) for vehicle, ONC or Ogerin (in GPR68+/+ and GPR68-/- mice) treated groups (Ogerin vs ONC, P = 0.0047; Ogerin vs Vehicle, P = 0.0014; Ogerin vs GPR68-/-, P = 0.0237; one-way ANOVA (main effect: P = 0.002; F(3, 18) = 7.367); with Dunnett’s multiple comparisons test; N = 5-6 animals per group).
November 4, 2025 at 4:49 PM