Michael Williamson
@m-r-williamson.bsky.social
PI at The Hospital for Sick Children and University of Toronto studying astrocyte biology, memory, neural repair. 🇨🇦 williamsonlab.ca
Excellent reporting on astrocyte-engram work from @junnagai.bsky.social, @m-r-williamson.bsky.social and others. This article captures just how much of a frontier research area astrocyte engrams represent, and I’m excited to see how the field unfolds. www.thetransmitter.org/memory/are-p...
Are parts of the memory trace found in the ‘astroengram?’
Neurons have long taken top billing in memory, but researchers are making the case for astrocytes.
thetransmitter.org
Very pleased to share our latest (now published), from star student Kamal Narayana. He finds lowering (not increasing) peri-infarct blood flow beyond the hyper-acute phase, improved stroke recovery by lessening blood brain barrier disruption and neuro-inflammation. www.nature.com/articles/s41...
Knockdown of endothelial Serpine1 improves stroke recovery by attenuating peri-infarct blood flow and blood-brain barrier disruption - Cell Death & Disease
Cell Death & Disease - Knockdown of endothelial Serpine1 improves stroke recovery by attenuating peri-infarct blood flow and blood-brain barrier disruption
nature.com
We're thrilled to share this #Perspective @natneuro.nature.com on #astrocytes as a multilayered system of #functional #units that operate across spatial scales. 👉Available for reading here: rdcu.be/fk0B7 👉Full article here: www.nature.com/articles/s41...
The multiple scales of astrocytic functional units - Nature Neuroscience
Astrocytes modulate complex brain functions. These ubiquitous glial cells constitute a multilayered system of functional units that operate across multiple spatial scales, thereby increasing the degre...
nature.com
Thrilled to share that I’ll be starting my lab at the SickKids Research Institute and University of Toronto in August! williamsonlab.ca Recruiting at all levels. Get in touch if you’re interested in astrocyte biology of cognition and disease!
Williamson Lab
The Williamson Lab studies astrocyte biology across development, cognition, and disease.
williamsonlab.ca
New paper from the lab. Using longitudinal ca imaging, activity-dependent tagging and optogenetics, we show that newly allocated fear engram neurons in amygdala undergo a brief period of coordinated “offline reverberation” immediately after learning. www.pnas.org/doi/10.1073/...
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
pnas.org
Sharing the latest from the lab. Led by Yunlong Liu, this work explores how microglia and engram neurons interact during fear extinction in the hippocampus. rdcu.be/fgNH7
Microglia-dependent regulation of fear memory extinction
Nature Neuroscience - Liu et al. show in mice that microglia are recruited to the soma and dendritic processes of fear engram neurons during extinction learning and that they weaken fear memories...
rdcu.be
Excited to share our latest in @currentbiology.bsky.social (they who publish the coolest papers!) Memories are encoded by sparse neuronal ensembles (engrams). But most evidence comes from "simple" associative learning tasks. What about more integrative memories like spatial navigation?
Incredibly proud of this paper led by @ossamaghenissa.bsky.social and @mathiasgua.bsky.social titled Basolateral 'Amygdala Astrocytes Encode Anxiety States'. www.cell.com/neuron/fullt... 🧵 below
Basolateral amygdala astrocytes encode anxiety states
Ghenissa et al. provide evidence that basolateral amygdala astrocytes reliably encode anxiety states. Using simultaneous in vivo calcium recordings across an array of behavioral tasks, combined with g...
cell.com
Super stoked to share that I’m starting my lab at UHN @dkjei-uhn.bsky.social / @kbi-uhn.bsky.social and the University of Toronto! If you’re interested in neuron-myelin interactions in circuit maturation and cognition, please reach out - we are hiring! www.oligodendrocyte.org 1/
Xin Lab
Welcome! We study the cellular interactions between neurons and oligodendrocytes, which produce myelin in the central nervous system. Myelination - the process by which oligodendrocytes ensheath neuro...
oligodendrocyte.org
How does the brain build a memory? A common assumption is that the neurons activated during an experience collectively form the memory engram. In our new Nature Neuroscience paper (finally out!), we show that this is not the case. www.nature.com/articles/s41...
Deconstruction of a memory engram reveals distinct ensembles recruited at learning - Nature Neuroscience
Pouget et al. identified distinct CA1 neuron ensembles active during specific moments of fear learning and uncovered the core engram essential for memory formation.
nature.com
Excited to share our new paper: We uncover a locus coeruleus→amygdala circuit linking β-adrenergic signaling to transcription regulation in defined amygdala cells during memory reconsolidation—+ stress or elevated noradrenergic signaling at recall can strengthen memory. www.cell.com/neuron/abstr...
A neuromodulatory circuit-to-molecular pathway for reformatting aversive memories during recall
Tan et al. identify a neuromodulatory circuit-to-molecular pathway in rats that updates aversive memories when they are recalled. Noradrenaline from the locus coeruleus triggers synapse-to-nuclear tra...
cell.com
Delighted to share our first preprint of the year! A project that we're all really proud of in the lab led by @ossamaghenissa.bsky.social with @mathiasgua.bsky.social in which we set out to test the role of basolateral amygdala astrocytes in anxiety behaviour. www.biorxiv.org/content/10.6...
Astrocytic Encoding of Threat in the Basolateral Amygdala
The basolateral amygdala (BLA) has long been implicated in threat detection and the generation of anxiety states. While previous experiments have demonstrated the important role of BLA principal neuro...
biorxiv.org
New preprint from the lab! For those who love astrocytes 🤩. We welcome feedback! #preprint #openaccess #astrocytes #autism
Metabolic, epigenetic and transcriptomic alterations in postnatal 16p11.2 deficient murine astrocytes
Autism Spectrum Disorders (ASD) are associated with metabolic dysregulation. While astrocytes are integral to cerebral metabolism, their molecular and functional changes in ASD are poorly known. Using...
biorxiv.org
Repair after CNS injury is not strictly local! We find that lesion-remote #astrocytes (LRAs) exhibit striking spatiotemporal heterogeneity across spared regions of the injured spinal cord and shape neural repair far from the injury epicenter! www.nature.com/articles/s41...
Lesion-remote astrocytes govern microglia-mediated white matter repair - Nature
After spinal cord injury, lesion-remote astrocytes acquire heterogeneous, spatially restricted reactivity states that shape neuroinflammation, neural repair and neurological recovery.
nature.com
Astrocytic Sox9 overexpression in Alzheimer’s disease mouse models promotes Aβ plaque phagocytosis and preserves cognitive function www.nature.com/articles/s41...
Finally it’s here! 🌟⬇️ www.nature.com/articles/s41... I’m sooo excited to share our latest article led by Steve Hill and Isabel Bravo-Ferrer 1- How does the vasculature communicate with astrocytes? 2- Is this communication dependent to what happens in the body. 3- Is it relevant to human diseases?
Fig. 1: Establishment of methods to identify astrocyte endfoot proteins. | Nature Communications
nature.com
Excited to share the latest from the lab on the molecular mechanisms of silencing and un-silencing a hippocampal engram ensemble. Was fun using a variant of the EPSILON technique developed by Adam Cohen's lab. (1/2) www.sciencedirect.com/science/arti...
Molecular mechanisms mediating engram ensemble retrievability state in mice
Engrams, ensembles of neurons that store memories, exist along a continuum of retrievability. Normally, sensory cues can reactivate a latent engram to…
sciencedirect.com
New paper from the lab 🚨 Led by Ali Golbabaei, this study explores the how the composition of prefrontal cortical engrams changes with memory age: authors.elsevier.com/a/1lzT-3BtfH...
authors.elsevier.com
Thrilled to share this work from my postdoc with Tom Carmichael, available online @ Neuron! Long story short: we find even more evidence that all reactive astrocytes are not equal, and we can take advantage of those differences to improve repair after stroke. www.sciencedirect.com/science/arti...
Regionally mapped astrocytic responses to cortical and white matter stroke show differential roles in astrocyte-induced vascular remodeling
Stroke is a major cause of disability. Astrocytes respond to stroke in a gradated manner, but details of that response and its consequences for tissue…
sciencedirect.com
New paper from the lab led by Ali Golbabaei. If you’re interested in systems consolidation, generalization and hippocampal neurogenesis a short 🧵 follows: authors.elsevier.com/a/1lsO73QW8S...
authors.elsevier.com
We have a new review out in TINS! A functional perspective on astrocyte heterogeneity www.cell.com/trends/neuro...
A functional perspective on astrocyte heterogeneity
Astrocytes are glial cells of the central nervous system (CNS) that perform an array of diverse functions that are essential for brain activity. Studies on the functional diversity of astrocytes sugge...
cell.com
Super interesting review on astrocyte development by @m-r-williamson.bsky.social and colleagues ! #astrocytes #glia #review
Development and diversity of astrocytes
Summary: This Development at a Glance article provides an overview of astrocyte ontogeny and morphogenesis, highlighting mechanisms that regulate the development of astrocytes, the most abundant glial...
doi.org
Absolutely thrilled to share the first half of my PhD work! Super proud to see it finally out! www.nature.com/articles/s41... Thread below for a quick (10 point) recap of what we found! 🧵🧪🧠
A divergent astrocytic response to stress alters activity patterns via distinct mechanisms in male and female mice - Nature Communications
Early-life stress has lifelong impacts on neuronal function and behavior. Here, the authors show that astrocytic glucocorticoid receptor signaling drives stress-induced neuronal and behavioral change ...
nature.com
Sharing our new short review on development and diversity of astrocytes! journals.biologists.com/dev/article-...
Development and diversity of astrocytes
Summary: This Development at a Glance article provides an overview of astrocyte ontogeny and morphogenesis, highlighting mechanisms that regulate the development of astrocytes, the most abundant glial...
journals.biologists.com
Happy to share new paper from MSc grads Myrthe and Jenna. We asked the question, when part of the brain dies during stroke, what happens to local and distant cortical neurons that innervate the stroke site (in S1 cortex) or those that receive outputs? journals.sagepub.com/doi/10.1177/...
Retrograde and anterograde trans-synaptic viral tracing of neuronal connections reveals local and distant effects of ischemic stroke on dendritic spines - Myrthe Van Sprengel, Jenna Butterworth, Patri...
Focal stroke leads to complex neurological disturbances with variable recovery. One explanation for this variability is that stroke disrupts local and remote ne...
journals.sagepub.com
Thought this would be a nice way to enter the bsky community👇Delighted for Katie (now in Chris Dulla's lab at Tufts). Thank you to our collaborators, to the reviewers and to Cagla Eroglu for the highlight! www.science.org/doi/10.1126/...
Norepinephrine signals through astrocytes to modulate synapses
Locus ceruleus (LC)–derived norepinephrine (NE) drives network and behavioral adaptations to environmental saliencies by reconfiguring circuit functional connectivity, but the underlying synapse-level...
science.org
Sharing a new paper from the lab. This paper, led by Sangyoon Ko, represents a merging of two longstanding research themes in the lab-- adult neurogenesis and systems consolidation. rdcu.be/el18q A short thread follows for those interested. 1/n
Systems consolidation reorganizes hippocampal engram circuitry
Nature - A study shows that loss of memory precision associated with systems consolidation can be explained by neurogenesis-dependent reorganization of engram circuitry within the hippocampus over...
rdcu.be
Thrilled to announce that my lab is now open at Ohio State! We study astrocytes as gene therapy targets for brain repair after ischemic stroke and in vascular dementia, developing new viral tools along the way. If you're interesting in joining or collaborating, please reach out! gleichmanlab.com
The Gleichman lab
gleichmanlab.com
Check out our latest paper today in Nature: “Goal specific hippocampal inhibition gates learning” www.nature.com/articles/s41... By Nuri Jeong, Xiao Zheng, Abby Paulson, Steph Prince and colleagues.
