Discovering Stem Cells
Professor Ronald McKay discusses how he identified stem cells, and how they can explain the fundamental molecular processes of the nervous system.
So, when we were working on this fundamental problem of how the nervous system was created, is the nervous system created from many different biologically distinct neuron types, the answer became very clear, yes indeed. So, then the problem was how are we ever going to understand this very complicated chemistry that gives rise to these neurons and controls the basic organization of the brain? Stem cells had already been suggested to exist by powerful experiments that had been done in other groups. And so I became very interested in the idea that we could identify these stem cells, and then if we could identify them, and then understand how they generate in the brain, then the stem cells would explain the fundamental processes, the molecular processes that control the organization and function of the nervous system. While that is a very ambitious kind of statement, it turns out basically to be true. Our work in the nervous system has been influential for people working in many other tissues and now this idea that stem cells are present in many tissues and that you can use them to understand the way tissues function is an idea that is very, very widely pursued.
neurons, neuron, brain, neuronal types, nervous, system
Professor Pat Levitt describes progenitor cells, which are immature, undifferentiated cells. They are the precursors to neurons.
Professor Ronald McKay explains that neurons in the hippocampus and olfactory bulb are unique in that they are produced throughout life. This is known as neurogenesis.
Professor Jeff Lichtman introduces the concept of synaptic competition, the process whereby nerve cells compete for space in the brain - much like protozoa in a very weird pond.
It is increasingly clear that the nonneuronal brain cells called glia are intricately involved in the neuronal crosstalk at synapses.
Researchers have identified three types of mirror neurons that respond to stimuli - 1) in reaching distance, 2) outside of reaching distance, and 3) both distances.
Gamma-aminobutyric acid (GABA) is a very common neurotransmitter in the Central Nervous System, whose primary function is to inhibit the transmission of a signal through a neuron.
Doctor Josh Dubnau explains that the genes active in different neurons can make them excitatory (e.g. glutamate) or inhibitory (e.g. GABA). These neurotransmitters are critical to learning.
An animation shows how drugs for SMA may be delivered via infusion into the spinal cord.
Abnormalities in a specific type of brain cells called mirror neurons have been associated with autism.
Professor Eric Kandel discusses the attributes that make Aplysia, a type of sea slug, an ideal model for studying learning and memory.