Level 1 - Absolute Beginner
Scientists did a new brain study in mice. It was in the journal Nature on October 8.
They made special mice. These mice did not grow most of their own brain cortex.
Then the scientists put a tiny piece of human brain tissue into the empty space. This tiny piece is called an organoid.
They want to learn how human brain cells grow and work inside a living brain.
- mouse
- a small animal with a long tail
- cortex
- the outer layer of the brain
- tissue
- a group of cells that work together
- organoid
- a tiny model of an organ grown in a lab
- journal
- a magazine for science papers
- cell
- the smallest living part of a body
- space
- an empty place
- learn
- to get new knowledge
Level 2 - Elementary
In its October 8 issue, the journal Nature highlights a new way to study human brain tissue. Researchers made mice that lack most of their own cerebral cortex and hippocampus.
They used a genetic strategy to create these mice. That left empty space in the brain.
The scientists then grafted a human cortical organoid into that space. An organoid is a small clump of human cells grown in a lab to copy part of an organ.
The aim is to let human brain tissue grow in a living brain. Researchers hope this will help them study how human neurons develop and connect.
- cerebral cortex
- the wrinkled outer part of the brain used for thinking
- hippocampus
- a part of the brain important for memory
- genetic
- related to genes
- strategy
- a plan to reach a goal
- graft
- to attach living tissue to another body
- neuron
- a nerve cell
- develop
- to grow and change over time
- aim
- a goal
Level 3 - Intermediate
A study highlighted in the October 8 issue of Nature describes a way to place human brain tissue inside a living animal brain. The researchers developed a genetic strategy that produces mice lacking most of the cerebral cortex and the hippocampus.
The missing tissue creates space, and into that space the team grafted a human cortical organoid, a three dimensional cluster of cells grown from stem cells to resemble part of the cortex.
Organoids are a popular research tool, but in a dish they lack blood vessels, a body and the signals a living brain provides. Placing one in a host brain is intended to give human cells a more realistic setting in which to mature and connect.
Such models might eventually help scientists examine conditions that are hard to study in people. As with any new method, it will take further work, and careful ethical discussion, to learn how well it mirrors the human brain.
- highlighted
- drew special attention to
- stem cells
- cells that can develop into many kinds of cells
- resemble
- to look or be similar to
- host
- the living body that receives something
- realistic
- like real life
- mature
- to become fully developed
- conditions
- medical problems
- ethical
- relating to what is right and wrong
Level 4 - Advanced
Among the papers featured in the October 8 issue of Nature is a study that tackles a long standing obstacle in neuroscience: how to let human brain tissue mature in a living brain. The authors devised a genetic strategy that yields mice born without most of their cerebral cortex and hippocampus, then grafted a human cortical organoid into the vacated territory.
Cortical organoids, spheres of cells coaxed from stem cells, have transformed the study of early human brain development, but a dish is an impoverished environment. It supplies no vasculature, no sensory input and none of the circuitry that shapes neurons in a real animal.
By clearing room in the host, the researchers sidestep the competition a graft would otherwise face from the mouse's own tissue, offering human cells an environment in which they may integrate more fully with a functioning brain.
The approach is a platform rather than a verdict. It raises scientific questions about how closely a chimeric brain can stand in for a human one, and ethical ones about where the boundary lies, both of which will shape how widely such models are adopted.
- obstacle
- something that blocks progress
- devised
- invented or planned
- territory
- an area of space
- coaxed
- gently persuaded or guided
- impoverished
- lacking richness or resources
- vasculature
- the network of blood vessels
- integrate
- to combine into a working whole
- chimeric
- made of cells from different species