Mysteries of the Human Brain
19/08/10 20:44 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Thu, 08/19/2010 - 20:44.
I concur with Derek Lowe, it is extremely naive to believe that a complete reverse-engineering of a human brain is only a decade away. Our brains feature in the order of a 100 billion neurons in addition to supporting cells. Over a hundred different types of cells appear to exist in the brain, most of which are poorly characterized.
Each neuron appears to be connected to about 1000 other neurons on average. How these neurons hook up to each other is strongly influenced by a wide range of genetic and environmental factors. These external factors include sensory inputs, changing effector output needs depending on the environment, energy and nutrient supply, blood flow, temperature, exposure to toxins, trauma, and psychological stress just to list a few. The precise physical connections between neurons appear to underlie our memories and ability to perceive and respond to the environment as well as carryout autonomic functions. The profound effects of the loss of a small portion of a person's neurons is particularly evident after a stroke or during Alzheimer's disease. As we die, all of the connections between our neurons disappear. For this reason, it is hard to reconcile any retention of memory or consciousness as we know it if one wanted to believe in life after death.
While understanding the architecture of connections between neurons in a precise manner is already daunting, elucidation of the linkages between proteins within neurons is even more challenging. Most of the 23,000 proteins encoded by the human genome are expressed in neurons, but our knowledge of their interactions remains rudimentary despite the sequencing of the human genome a decade ago. We are still just starting to learn how neurons work. It is also clear that the brain is not created in isolation, but rather as part of a complex developmental program in conjunction with other organs and tissues.
Nope! Contrary to the optimistic opinions of visionaries like Ray Kurzwell, I think that it will take many more decades at the current pace of research to generate a comprehensive understanding of how we really work. We are still mastering the fundamentals. As Craig Venter once aptly said, "Sequencing the human genome was just a race to the starting line."
Link to the original blog post.
I concur with Derek Lowe, it is extremely naive to believe that a complete reverse-engineering of a human brain is only a decade away. Our brains feature in the order of a 100 billion neurons in addition to supporting cells. Over a hundred different types of cells appear to exist in the brain, most of which are poorly characterized.
Each neuron appears to be connected to about 1000 other neurons on average. How these neurons hook up to each other is strongly influenced by a wide range of genetic and environmental factors. These external factors include sensory inputs, changing effector output needs depending on the environment, energy and nutrient supply, blood flow, temperature, exposure to toxins, trauma, and psychological stress just to list a few. The precise physical connections between neurons appear to underlie our memories and ability to perceive and respond to the environment as well as carryout autonomic functions. The profound effects of the loss of a small portion of a person's neurons is particularly evident after a stroke or during Alzheimer's disease. As we die, all of the connections between our neurons disappear. For this reason, it is hard to reconcile any retention of memory or consciousness as we know it if one wanted to believe in life after death.
While understanding the architecture of connections between neurons in a precise manner is already daunting, elucidation of the linkages between proteins within neurons is even more challenging. Most of the 23,000 proteins encoded by the human genome are expressed in neurons, but our knowledge of their interactions remains rudimentary despite the sequencing of the human genome a decade ago. We are still just starting to learn how neurons work. It is also clear that the brain is not created in isolation, but rather as part of a complex developmental program in conjunction with other organs and tissues.
Nope! Contrary to the optimistic opinions of visionaries like Ray Kurzwell, I think that it will take many more decades at the current pace of research to generate a comprehensive understanding of how we really work. We are still mastering the fundamentals. As Craig Venter once aptly said, "Sequencing the human genome was just a race to the starting line."
Link to the original blog post.