Matt Kirkcaldie

@matttkk

Obsessed with brain structure and comparative neuroanatomy. They’re not circuits. It’s not wiring. Cortex is a resonant mesh. [ image by ]

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Matt Kirkcaldie@matttkk· 6d

Morning fogs in Hobart make dreamlike landscapes - the Bridgewater Jerry is quite the artist.

Planes of deep blue hills and pale blue banks of fog, with black silhouettes of houses in the foreground.

Planes of deep blue hills and pale blue banks of fog, with black silhouettes of houses in the foreground. Above, a cloudy sky in similar hues with hints of warmer sunrise.

Matt Kirkcaldie@matttkk· 8d

Fascinating that Australian butcherbirds are in a different superfamily (Malaconotoidea > Artamidae) than the loggerhead shrike (Corvoidea > Laniidae), but share similar approaches to life and the same team colours:

Two Australian Butcherbirds on a fence in Brisbane. Their heads are black, with long grey wedged beaks having a hooked tip. Their bodies are pale grey with distinctly darker grey wings, black wingtips and tail tipped with white. Photo by Tatiana Gerus via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Cracticus_torquatus_-Brisbane_-garden_fence-8.jpg

Matt Kirkcaldie@matttkk· 21d

Conceptually delighted and weirdly repelled by Julia Stack's vision of the "spinal homunculus" - the body scaled by numbers of spinal motor neurons devoted to each part. In its lap is the motor cortex equivalent, with large representations of the hands and face. academic.oup.com/brain/articl...

Oddly creepy illustration of a pensive, seated humanlike figure with bizarrely thick, stubby arms and legs joined by a trunk so thin it looks like just the spine, without organs. This is due to the large numbers of spinal motor neurons devoted to the limbs and digits, and not much else. In its lap stands a small blue human-ish figure with giant hands and exaggerated facial features, the rest of its body doll-like in proportion, indicating the relative size of cortical motor areas corresponding to these body parts.

Matt Kirkcaldie@matttkk· Jul 6

These are intermediate filament proteins; there's a family of IFs specialised to some of the axons of neurons which similarly capture water in a "skin", resulting in the interior of the axon becoming a linear gel. That's how axons stay intact while bending. @christlet.bsky.social is the NF master!

Cross section diagram of an axon showing bundles of microtubules (MT, red) packed in among long, water-gel fibres of neurofilaments (NF, in green), filling the space inside the jacket of the axon. Fig 1 from Kirkcaldie MTK, Collins JM. The axon as a physical structure in health and acute trauma. J Chem Neuroanat 2016;76:9-18. doi:10.1016/j.jchemneu.2016.05.006

Matt Kirkcaldie@matttkk· Jul 2

One of the reasons I persist with Apple is not shovelling my personal, professional and creative data into the gaping, plagiarist, resource-torching maw of AI data mining (analysis by @ketanjoshi.co) bsky.app/profile/keta...

Reported power consumption figures for Amazon, Apple, Google, Meta and Microsoft, 2013-2025. All are increasing exponentially except Apple which maintains a low usage around 3 TWh/yr, compared to Google's ~43 TWh/yr in 2024-5.

Matt Kirkcaldie@matttkk· May 7

Happy 100th birthday, Sir David Attenborough. Seeing Life on Earth aged 9 fired me with a joy and fascination for living things which has never let go. Hundreds of millions alike have been inspired by his thoughtful, incisive, delightful engagement with the natural world. Who else has such a legacy?

Sir David Attenborough with the mountain gorillas of Rwanda in 1978. The gorillas are in focus, not Sir David, which is the way he would prefer it.

Matt Kirkcaldie@matttkk· Apr 22

@remhq.bsky.social

The sleeve of R.E.M.’s album Reckoning, which closely resembles the Allen Institute’s organoid image.

Matt Kirkcaldie@matttkk· Mar 16

So – last week I had a peer review to do for a journal from a major publisher, an overview article by well published researchers. It was late, so I stayed back to work on it. Some hours in, a few things snapped into focus, and I realised that large chunks had been “written” by generative AI. (1/12)

The "is this ... a pigeon?" meme with the title Peer Review, a bookish young man regarding a butterfly tagged "Gen-AI slop", asking innocently "is this ... a scientific article?"

Matt Kirkcaldie@matttkk· Mar 3

My favourite. ... and, look at the Great Red Spot these days (telescopic image by Tiziano Olivetti on March 1st 2026, via ALPO-J):

Telescopic image of Jupiter, softly lit with brown-grey bands and a Great Red Spot less than half the size it was in Pioneer probe images. Image details:
Tiziano Olivetti
Unione Astrofili Italiani
DK 505 mm - Zen Optics. t=10,500 mm
Camera BFS-28S5M-C IMX421 Astrodon RGB filters
2026-03-01, 13:18.7 UT CM I 297.8° CM II 81.5° CM III 345.0°
eq.diam.=42.5" Altitude 79 deg

Matt Kirkcaldie@matttkk· Feb 23

1983 Radio Shack Model 100 laptop with a full keyboard and an LCD screen, showing Microsoft Basic with 29382 bytes free

Matt Kirkcaldie@matttkk· Jan 30

Devastated for your loss, that's a glorious car to have owned. This is still my daily driver (2011 159 Ti TBi)

A red Alfa Romeo 159 Ti TBi sedan in dappled shade

Matt Kirkcaldie@matttkk· Jan 27

Excited to discover that the renowned Prof Marian Stamp Dawkins recently released a book addressing one of my most pressing interests – consciousness in nonhuman animals – and that it's available open-access from Oxford University Press. Will read with great interest. global.oup.com/academic/pro...

Cover of Marian Stamp Dawkins' book "Who is Conscious? A Guide to the Minds of Animals" showing a forest glade lit by a shaft of light, surrounded by dark tall trees.

Matt Kirkcaldie@matttkk· Jan 13

It's hard to convey the delight of a 1944 monograph leading you to a German research paper from 1878 making reference to a Latin tract published in Prague, 1868, for the anniversary of Purkinje ... and finding out it's been scanned and preserved on the Internet Archive. @archive.org

Cross section of the tail of a lizard, showing the central vertebra with the spinal cord inside, surrounded by radiating blood vessels and meshlike capillary beds inside an oval of green spiky skin.
from Schöbl 1868 "Retia mirabilia circumvertebralia quorumdam Sauriorum, qui magna fragilitate caudae praediti sunt."

Matt Kirkcaldie@matttkk· Jul 13

A favourite #neuroanatomy study: Lewis Weed making paper cutouts of brainstem sections, stacking them in register, then drawn by Max Brödel. Over a century old but still fresh! Weed LH. A reconstruction of the nuclear masses in the lower portion of the human brain-stem. Carnegie Inst. Wash., 1914.

Ventral surface of the human brainstem showing the nuclei in three dimensional, precise rendering, lightly tinted to show distinctions. Drawing by Max Brödel, lithography by A. Hoen and Co., 1914.

Lateral aspect of the human brainstem showing the nuclei in three dimensional, precise rendering, lightly tinted to show distinctions. Drawing by Max Brödel, lithography by A. Hoen and Co., 1914.

Lateral view of midline section of the human brainstem, showing the nuclei in three dimensional, precise rendering, lightly tinted to show distinctions. The spinal aqueduct can be seen coursing down from the fourth ventricle. Drawing by Max Brödel, lithography by A. Hoen and Co., 1914.

Dorsal aspect of the human brainstem showing the nuclei in three dimensional, precise rendering, lightly tinted to show distinctions. The floor of the fourth ventricle is apparent on the right side. Drawing by Max Brödel, lithography by A. Hoen and Co., 1914.

Matt Kirkcaldie@matttkk· Jul 10

Did not expect to see a barrelfield in the morning sky here #neuroanatomy #cortex

Winter cloud patterns in which one dark cloud resembles the pattern of the mouse S1BF cortical region.

Matt Kirkcaldie@matttkk· Jul 8

"Brainbow" multi-neuron labelling in mouse brain (Jean Livet, 2007).

Strands of false-colour rainbow-labelled axon fibres, wrapped in bundles together, passing across the image and cut by the plane of sectioning.

Matt Kirkcaldie@matttkk· Jan 29

OK - here's a human cortex diagram I made for a lecture, intended to show that primary regions (M1, S1, A1, V1) are surrounded by fields of increasing abstraction related to them, and that across the postcentral cortex these influences mix. I'm interested to hear whether you think it's useful.

A lateral view of the human cerebral cortex with the frontal lobe shaded yellow in the M1 strip, fading forwards toward prefrontal areas to indicate higher levels of motor planning. The post-central cortex is a three-way gradient of somatosensory (fading caudally from S1), visual (fading rostrally from V1 at the occipital pole) and auditory (fading outward from the inner bank of the temporal lobe). Primary and secondary motor and sensory regions are indicated.

Matt Kirkcaldie@matttkk· Dec 3

Also the planet is missing the polar hexagon, and about 15% too large compared to the rings:

Comparison of AI image of Saturn with Cassini image scaled so the rings are equal size, indicated by red lines. Blue lines spanning the planet in the AI image are clearly considerably wider than the true diameter of the planet in the Cassini image.

Matt Kirkcaldie@matttkk· Nov 28

Charles Watson and I were writing The Brain: An Introduction to Functional Neuroanatomy and I wanted to show the complexity of an astrocyte. I coloured each layer of this confocal stack from the CCDB: green at the rear, cycling blue, red then yellow in front. The green branch wraps a capillary.

A fuzzy, complex cell with radiating branches in pink, red and yellow, with one green branch extending down and right to where it would wrap around a blood vessel

Matt Kirkcaldie@matttkk· Nov 22

Pleased to meet a traveller in my kitchen this morning - a pink bellied moth, Oenochroma vinaria, identified thanks to @kristiellingsen.bsky.social 's wonderful website.

A reddish brown moth with wide swept, pointed wings that mimic a dead eucalyptus leaf, against a white wall.

Matt Kirkcaldie@matttkk· Nov 22

Yeah, 86 according to Azevedo et al. J Comp Neurol. 2009;513(5):532-41. doi:10.1002/cne.21974 These figures which also explain the sampling:

Matt Kirkcaldie@matttkk· Nov 21

Delighted for Laura De Paoli in Dr Jess Collins' lab at the Wicking Centre - her first paper is a review of the complex landscape of neurofilament biomarkers in neurodegenerative diseases. She's done the hard yards so you don't have to! Free here: www.researchgate.net/publication/...

Graphical abstract describing the process of detecting neurofilament proteins in blood and serum as a diagnostic tool - details in the article!

Matt Kirkcaldie@matttkk· Nov 20

Viz (adapted from Caviness and Frost 1980) - the MD projection is probably 5% of the flattened cortical sheet and tucked underneath, near the olfactory tract.

A semicircular map showing a flattened hemisphere of the mouse cortex, oriented with rostral to the left and medial to the bottom. MD projections cover a thin fringe on the right edge. AD, anterodorsal; DLG, dorsal lateral geniculate; LDVL, laterodorsal, ventrolateral part; LPLR, lateral posterior, laterorostral part; LPMR, lateral posterior, mediorostral part; MD, mediodorsal; MGV, medial geniculate, ventral part; PIL, posterior intralaminar; Po, posterior group; PoM, posteromedian; VL, ventrolateral; VM, ventromedial; VPL, ventral posterolateral; VPM, ventral posteromedial.

Matt Kirkcaldie@matttkk· Nov 15

Here's an oldie - in the 2000s, working with the Paxinos lab towards a myelin atlas of the mouse brain, using the glorious Gallyas silver stain (Gallyas F. Acta Morphol Acad Sci Hung 1971;19:1–8). Could not get a complete set to work after a year of trying, but individual sections were spectacular!

Matt Kirkcaldie@matttkk· Nov 13

I don't know if this counts as microscopy - it was a 60mm macro - but here's a little something:

A jumping spider about 7mm long, standing on a red clay brick and holding the corpse of a small housefly the same size as itself.

A jumping spider holding the corpse of a small housefly, eyeing the camera from the edge of a housebrick.

A jumping spider dragging the corpse of a housefly to its shelter.

Matt Kirkcaldie@matttkk· Nov 11

If you see this, post a concert pic you took: Michael Rother @ Museum of Old and New Art, Tasmania, Feb 25 2024.

Matt Kirkcaldie@matttkk· Nov 8

Another PhD candidate of ours, Aidan O'Mara, wrote a very nice open-source machine-learning-based segmentation tool for ImageJ / FIJI to help us quantify these things accurately and with as little bias as possible - check it out! www.researchgate.net/publication/...

Matt Kirkcaldie@matttkk· Nov 8

A lovely image by Ellie Bucher: perineuronal nets (green; WGA) around parvalbumin-labelled interneurons (red) near amyloid deposits (blue; Amylo-glo) in the cortex of an APPswe-PS1dE9 mouse. This network is a critical enabler of cortical processing; see our review: link.springer.com/epdf/10.1007...

On a black background, scattered bands of red cell bodies over a haze of reddish connections, with rings of green surrounding most. Lurking in the background are blue shadows a bit larger than the cell bodies.

Matt Kirkcaldie@matttkk· Oct 11

Sometimes, you go to the beach at night to look for penguins returning home, and this happens

A bright aurora australis with green rays and bars over a red glow, behind a few small clouds

Matt Kirkcaldie@matttkk· Jan 30

awwww