Changing stroke rehab and research worldwide now.Time is Brain! trillions and trillions of neurons that DIE each day because there are NO effective hyperacute therapies besides tPA(only 12% effective). I have 523 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there. Did your doctor somehow miss the recovery protocol that Pedro Bach-y-Rita used to recover fully back in 1958 with only a partial brain?

What this blog is for:

My blog is not to help survivors recover, it is to have the 10 million yearly stroke survivors light fires underneath their doctors, stroke hospitals and stroke researchers to get stroke solved. 100% recovery. The stroke medical world is completely failing at that goal, they don't even have it as a goal. Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It lays out what needs to be done to get stroke survivors closer to 100% recovery. It's quite disgusting that this information is not available from every stroke association and doctors group.

Showing posts with label memory formation. Show all posts
Showing posts with label memory formation. Show all posts

Sunday, October 25, 2026

Astrocyte Subtypes Drive Synapse Formation and Memory

 How long will it take your INCOMPETENT? DOCTOR  to create protocols from this to get you recovered?  

Anything longer than a week IS PURE INCOMPETENCE!

Do you prefer your doctor, hospital and board of director's incompetence NOT KNOWING? OR NOT DOING? Your choice; let them be incompetent or demand action! NO excuse for such blatant incompetence!

Astrocyte Subtypes Drive Synapse Formation and Memory

Summary:

A landmark study published in Nature by researchers at Baylor College of Medicine reveals that astrocytes—the most abundant support cells in the central nervous system—are not a uniform population. By developing novel transgenic tools to separate astrocytes based on the surface receptor CD51, the team discovered that CD51-positive (CD51+) astrocytes carry out specialized duties: they build synapses via glypican 6 in the cortex, drive circuit rewiring in the hippocampus to support memory, and orchestrate functional neural recovery following ischemic stroke.

Key Facts:

  • Functional Specialization: Astrocytes are divided into functionally distinct subtypes defined by the presence or absence of the surface receptor CD51, disproving the long-held assumption that astrocytes act as homogenous support cells.
  • Synapse Assembly via Glypican 6: In both the developing and injured cerebral cortex, CD51+ astrocytes actively construct synaptic junctions between neurons through the secretion of glypican 6, a capacity entirely lacking in CD51- astrocytes.
  • Hippocampal Rewiring & Stroke Repair: In the hippocampus, CD51+ astrocytes directly mediate circuit plasticity essential for learning and memory; following stroke, they spearhead synaptic remodeling to restore neurological motor function.

Source: Baylor College of Medicine

For more than a century, neuroscience recognized neurons as the primary specialists of the brain, categorized into intricate classes of excitatory, inhibitory, sensory, and motor cells. By contrast, astrocytes, the star-shaped glial cells that outnumber neurons across the brain and spinal cord, were largely viewed as a uniform collective of caretaker cells tasked with metabolic support, blood-brain barrier maintenance, and general homeostasis.

Now, a pioneering study from Baylor College of Medicine published in Nature overturns this dogma.

Led by senior author Benjamin Deneen, PhD, the research team demonstrated that astrocytes comprise specialized functional subtypes with dedicated physiological roles. Using newly engineered transgenic mouse lines, the investigators discovered that astrocytes marked by the surface protein CD51 perform essential architectural tasks: constructing synaptic junctions, tuning hippocampal memory circuits, and repairing neural pathways following ischemic stroke.

Developing Tools to Unmask Glial Diversity

While recent single-cell RNA sequencing studies suggested that astrocytes exhibit molecular heterogeneity across different brain regions, whether these transcriptional signatures translated into distinct functional roles in the living brain remained an open question.

The Baylor team zeroed in on CD51 (integrin alpha V), a cell-surface receptor protein expressed on a distinct subset of astrocytes.

“We set out to test whether astrocytes that carry CD51 (CD51+) and those that don’t (CD51-) work differently in living brain circuits, but no animal models or lab tools existed that would let us do that,” said co-first author Junsung Woo, PhD, assistant professor at Baylor’s Center for Cancer Neuroscience. “So we first developed a new mouse line and a set of lab tools that let us label and control CD51+ and CD51- astrocytes separately in a living brain. With these tools, we could compare the two groups side by side in the cerebral cortex and in the hippocampus across developing, adult, and injured brains.”

Division of Labor: Synaptogenesis and Memory Circuit Tuning

The experiments revealed that CD51+ and CD51- astrocytes represent entirely distinct cellular populations displaying unique morphologies, developmental timelines, and physiological duties.

In the developing and adult cerebral cortex, the brain region responsible for sensory perception, cognition, and motor control, CD51+ astrocytes functioned as master builders of neuronal connectivity.

“We discovered that CD51+ astrocytes have a specialized job: they help form synapses, the junctions where neurons pass messages to each other—in the developing and injured cortex. CD51- astrocytes don’t do this,” explained co-first author Michael Williamson, PhD, assistant professor at the University of Toronto and scientist at the Hospital for Sick Children. “CD51+ astrocytes do this job using a protein called glypican 6.”

The specialization was equally stark in the hippocampus, the brain’s epicenter for memory formation and spatial navigation. Here, CD51+ astrocytes directly governed synaptic plasticity. Rather than relying on secondary secreted factors, the surface CD51 protein itself drove the structural rewiring and adaptation of hippocampal circuits necessary for learning.

Spearheading Brain Repair After Ischemic Stroke

The therapeutic importance of this astrocyte division of labor became evident when the researchers examined models of brain injury.

Following an ischemic stroke, damaged neural networks must re-establish lost connections to restore motor and cognitive function. The team observed that CD51+ astrocytes migrated to the peri-infarct cortex and actively remodeled damaged synaptic circuits. In contrast, CD51- astrocytes failed to facilitate this structural repair, demonstrating that functional recovery after acute brain trauma depends heavily on the activity of this specialized subpopulation.

“Altogether, our findings change how we think about astrocytes,” said Dr. Deneen, professor and Dr. Russell J. and Marian K. Blattner Chair in the Department of Neurosurgery, Center for Cell and Gene Therapy, and director of the Center for Cancer Neuroscience at Baylor. “For a long time, astrocytes were considered largely uniform. We’ve shown that they include specialized subtypes with distinct jobs in the developing, adult, and injured brain, much like what we see for neurons. Going forward, studies of astrocytes in health and disease will need to consider which subtypes are involved.”

The discovery provides a new framework for neurotherapeutics. Rather than applying broad glial-targeting agents, future treatments for neurodevelopmental delays, memory disorders, and stroke rehabilitation may focus on selectively modulating CD51+ astrocytes to accelerate synaptic regeneration.

Funding: This work was supported by the National Institutes of Health (grants R35-NS132230, R01-AG071687 and R56-MH133822), the American Heart Association (grants 23POST1019413 and 25POST1363224), the David and Eula Wintermann Foundation and the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health (award P50HD103555).

Editorial Notes:

  • This article was edited by a Neuroscience News editor.
  • Journal paper reviewed in full.
  • Additional context added by our staff.

About this neuroscience Research:

  • Media Contact: Graciela Gutierrez
  • Source: Baylor College of Medicine
  • Image Credit: Image credited to Neuroscience News
  • Original Research is Open Access: Nature (Oct 1, 2026). “CD51 delineates functionally distinct astrocyte subtypes in neural circuits.” Authors: Junsung Woo, Michael R. Williamson, Dongjoo Choi, Ekin Akdemir, Thea Zlatkov, Kwanha Yu, Wookbong Kwon, Ehson Maleki, Yeunjung Ko, Kaitlyn Sanchez, Hussein Maleki, Jong Min Choi, Akdes Serin-Harmanci & Benjamin Deneen.
  • DOI: 10.1038/s41586-026-11186-z

Thursday, June 13, 2024

Saturday, June 8, 2024

Brain’s Oxygen Deprivation Mechanism Hinders Memory Formation

 Ask your competent? doctor how long after your stroke this memory problem continues and how EXACTLY your doctor is treating the problem. NO treatment? You don't have a functioning stroke doctor!

Brain’s Oxygen Deprivation Mechanism Hinders Memory Formation

Summary: Oxygen deprivation in the brain triggers a feedback loop involving glutamate and nitric oxide, causing anoxia induced long-term potentiation (aLTP). This process disrupts regular memory-enhancing mechanisms, potentially explaining memory loss post-stroke. The study offers insights into treating memory problems in stroke patients.

Key Facts:

  1. aLTP occurs during temporary oxygen deprivation in the brain, impairing memory.
  2. Glutamate and nitric oxide form a feedback loop that sustains aLTP.
  3. Disrupting this loop may help restore normal memory function after strokes.

Source: OIST

When we learn something new, our brain cells (neurons) communicate with each other through electrical and chemical signals. If the same group of neurons communicate together often, the connections between them get stronger. This process helps our brains learn and remember things and is known as long-term potentiation or LTP.  

Another type of LTP occurs when the brain is deprived of oxygen temporarily – anoxia-induced long-term potentiationor aLTP. aLTP blocks the former process, thereby impairing learning and memory. Therefore, some scientists think that aLTP might be involved in memory problems seen in conditions like stroke. 

Researchers at the Okinawa Institute of Science and Technology (OIST) and their collaborators have studied the aLTP process in detail. They found that maintaining aLTP requires the amino acid glutamate, which triggers nitric oxide (NO) production in both neurons and brain blood vessels. This process forms a positive glutamate-NO-glutamate feedback loop.

Their study, published in iScience, indicates that the continuous presence of aLTP could potentially hinder the brain’s memory strengthening processes and explain the memory loss observed in certain patients after experiencing a stroke.  

The brain’s response to low oxygen 

When there is a lack of oxygen in the brain, glutamate, a neurotransmitter, is released from neurons in large amounts. This increased glutamate causes the production of NO. NO produced in neurons and brain blood vessels boosts glutamate release from neurons during aLTP. This glutamate-NO-glutamate loop continues even after the brain gets enough oxygen. 

“We wanted to know how oxygen depletion affects the brain and how these changes occur,” Dr. Han-Ying Wang, a researcher in the former Cellular and Molecular Synaptic Function Unit at OIST and lead author of the study, stated.

“It’s been known that nitric oxide is involved in releasing glutamate in the brain when there is a shortage of oxygen, but the mechanism was unclear.”  

During a stroke, when the brain is deprived of oxygen, amnesia – the loss of recent memories – can be one of the symptoms. Investigating the effects of oxygen deficiency on the brain is important because of the potential medicinal benefits.

“If we can work out what’s going wrong in those neurons when they have no oxygen, it may point in the direction of how to treat stroke patients,” Dr. Patrick Stoney, a scientist in OIST’s Sensory and Behavioral Neuroscience Unit and former member of the Cellular and Molecular Synaptic Function Unit, explained. 

Brain tissues from mice were placed in a saline solution, mimicking the natural environment in the living brain. Normally, this solution is oxygenated to meet the high oxygen demands of brain tissue. However, replacing the oxygen with nitrogen allowed the researchers to deprive the cells of oxygen for precise lengths of time.  

The tissues were then examined under a microscope and electrodes were placed on them to record electrical activity of the individual cells. The cells were stimulated in a way that mimics how they would be stimulated in living mice. 

Stopping memory and learning activity 

The scientists found that maintaining aLTP requires NO production in both neurons and in blood vessels in the brain. Collaborating scientists from OIST’s Optical Neuroimaging Unit showed that in addition to neurons and blood vessels, aLTP requires the activity of astrocytes, another type of brain cell. Astrocytes connect and support communication between neurons and blood vessels. 

“Long-term maintenance of aLTP requires continuous synthesis of nitric oxide. NO synthesis is self-sustaining, supported by the NO-glutamate loop, but blocking molecular steps for NO-synthesis or those that trigger glutamate release eventually disrupt the loop and stop aLTP,” Prof. Tomoyuki Takahashi, leader of the former Cellular and Molecular Synaptic Function Unit at OIST, explained.  

Notably, the cellular processes that support aLTP are shared by those involved in memory strengthening and learning (LTP). When aLTP is present, it hijacks molecular activities required for LTP and removing aLTP can rescue these memory enhancing mechanisms.

This suggests that long-lasting aLTP may obstruct memory formation, possibly explaining why some patients have memory loss after a short stroke. 

Prof. Takahashi emphasized that the formation of a positive feedback loop formed between glutamate and NO when the brain is temporarily deprived of oxygen is an important finding. It explains long-lasting aLTP and may offer a solution for memory loss caused by a lack of oxygen.  

About this memory and neuroscience research news

Author: Tomomi Okubo
Source: OIST
Contact: Tomomi Okubo – OIST
Image: The image is credited to Neuroscience News

Original Research: Open access.
“Anoxia-induced hippocampal LTP is regeneratively produced by glutamate and nitric oxide from the neuro-glial-endothelial axis” by Han-Ying Wang et al. iScience

Sunday, August 15, 2021

Memory formation in the motor cortex ipsilateral to a training hand

 I'm not sure how this is going to help you get 100% recovered. Lots of big words though.

Memory formation in the motor cortex ipsilateral to a training hand

J. Duque
1,2
, R. Mazzocchio
1,3
, K. Stefan
1
, F. Hummel
1,4
,E. Olivier
2
and Leonardo G. Cohen
11
Human Cortical Physiology Section and StrokeNeurorehabilitation Clinic, National Institute of NeurologicalDisorders and Stroke, National Institutes of Health, Bethesda,MD 20817, USA,
 2
Laboratoire de Neurophysiologie, Universite ´catholique de Louvain, B-1200 Brussels, Belgium,
 3
Sezione diNeurofisiologia Clinica, Dipartimento di Scienze Neurologichee del Comportamento, Universita’ di Siena, I-53100 Siena, Italy and
 4
Cortical Physiology Research Group, Department of Neurology, University Medical Center Hamburg-Eppendorf,20246 Hamburg, Germany
Cortical reorganization within the primary motor cortex (M1)contralateral to a practicing hand has been extensively investigated. The extent to which the ipsilateral M1 participates in these plastic changes is not known. Here, we evaluated the influence of unilateral hand practice on the organization of the M1 ipsilateral and contralateral to the practicing hand in healthy human subjects.Index finger movements elicited by single-pulse transcranial magnetic stimulation (TMS) delivered to each M1 were evaluated before and after practice of unilateral voluntary index fingerabduction motions. Practice increased the proportion and acceleration of TMS evoked movements in the trained direction and the amplitude of motor-evoked potentials (MEPs) in the abduction agonist first dorsal interosseous (FDI) muscle in the practicing hand and decreased the proportion and acceleration of TMS evoked abduction movements and MEP amplitudes in the abduction agonist FDI in the opposite resting hand. Our findingsindicate that unilateral hand practice specifically weakened there presentation of the practiced movement in the ipsilateral M1 to an extent proportional to the strengthening effect in the contralateral M1, a result that varied with the practicing hand’s position. These results suggest a more prominent involvement of interacting bilateral motor networks in motor memory formation and probably acquisition of unimanual motor skills than previously thought.