The researchers show that brain organoids—clumps of lab-grown neurons—can integrate with rat brains and respond to visual stimulation like flashing lights.
Decades of research has shown that we can transplant individual human and rodent neurons into rodent brains, and, more recently, it has been demonstrated that human brain organoids can integrate with developing rodent brains. However, whether these organoid grafts can functionally integrate with the visual system of injured adult brains has yet to be explored.
“We focused on not just transplanting individual cells, but actually transplanting tissue,” says the senior author. “Brain organoids have architecture; they have structure that resembles the brain. We were able to look at individual neurons within this structure to gain a deeper understanding of the integration of transplanted organoids.”
The researchers cultivated human stem cell-derived neurons in the lab for around 80 days before grafting them into the brains of adult rats that had sustained injuries to their visual cortex. Within three months, the grafted organoids had integrated with their host’s brain: becoming vascularized, growing in size and number, sending out neuronal projections, and forming synapses with the host’s neurons.
The team made use of fluorescent-tagged viruses that hop along synapses, from neuron to neuron, to detect and trace physical connections between the organoid and brain cells of the host rat. “By injecting one of these viral tracers into the eye of the animal, we were able to trace the neuronal connections downstream from the retina,” says the author. “The tracer got all the way to the organoid.”
Next, the researchers used electrode probes to measure the activity of individual neurons within the organoid when the animals were exposed to flashing lights and alternating white and black bars. “We saw that a good number of neurons within the organoid responded to specific orientations of light, which gives us evidence that these organoid neurons were able to not just integrate with the visual system, but they were able to adopt very specific functions of the visual cortex.”
The team was surprised by the degree to which the organoids were able to integrate within only three months. “We were not expecting to see this degree of functional integration so early,” says the author. “There have been other studies looking at transplantation of individual cells that show that even 9 or 10 months after you transplant human neurons into a rodent, they're still not completely mature.”
“Neural tissues have the potential to rebuild areas of the injured brain,” says the author. “We haven't worked everything out, but this is a very solid first step. Now, we want to understand how organoids could be used in other areas of the cortex, not just the visual cortex, and we want to understand the rules that guide how organoid neurons integrate with the brain so that we can better control that process and make it happen faster.”
https://www.cell.com/cell-stem-cell/fulltext/S1934-5909(23)00004-8
http://sciencemission.com/site/index.php?page=news&type=view&id=publications%2Fstructural-and_11&filter=22
Integration of human forebrain organoids with the injured adult rat visual system
- 1,168 views
- Added
Latest News
Circadian rhythms can influ…
By newseditor
Posted 27 Apr
With hybrid brains, these m…
By newseditor
Posted 27 Apr
Blocking activation of NF-κ…
By newseditor
Posted 27 Apr
Vitamin D regulates microbi…
By newseditor
Posted 27 Apr
Role of alternative splicin…
By newseditor
Posted 27 Apr
Other Top Stories
Capturing 5 different signal types from multiple locations in a liv…
Read more
SPOTing the subcellular lipid membranes
Read more
Patience brain circuit unraveled!
Read more
Electronic skin with artificial multimodal receptors that can feel
Read more
Silicon-based, disposable, all-in-one micro-qPCR for rapid on-site…
Read more
Protocols
A programmable targeted pro…
By newseditor
Posted 23 Apr
MemPrep, a new technology f…
By newseditor
Posted 08 Apr
A tangible method to assess…
By newseditor
Posted 08 Apr
Stem cell-derived vessels-o…
By newseditor
Posted 06 Apr
Single-cell biclustering fo…
By newseditor
Posted 01 Apr
Publications
Single dose creatine improv…
By newseditor
Posted 27 Apr
Autonomous circadian rhythm…
By newseditor
Posted 27 Apr
Functional sensory circuits…
By newseditor
Posted 27 Apr
Positive selection CRISPR s…
By newseditor
Posted 27 Apr
Focal clusters of peri-syna…
By newseditor
Posted 27 Apr
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar