The Thalamus - The Kernel in Your Mind 217
corbettw writes "This article on Yahoo Science News describes a new finding that explains how the thalamus is used by your brain to essentially boot your brain, and provide for central processing and control of all impulses going to and from the cortex. The article describes its function as an operating system, but from the description it actually seems closer to the functions of a kernel." From the article: "The finding, published last week in the journal Neuroscience, changes the way scientists understand nitric oxide's role in the brain, and it also has them rethinking the function of the thalamus, where it is released. The thalamus was thought to be a fairly primitive structure, sort of a gate that could either open and allow sensory information to stream into the cortex, the higher functioning part of the brain, or cut off the flow entirely. Godwin says the new research shows it's more accurate to think of the thalamus not as a gate but as a club bouncer, who doesn't simply allow a huge rush of people to go in or no one at all, but picks and chooses whom to let in and out. "
Brain vs. computer comparisons only go so far (Score:4, Informative)
Anyway, this is an interesting article. This research has a lot of promise in coming years and decades as better understanding brain chemistry advances pharmaceuticals and medical treatments. From TFA: "This study shows a unique role for nitric oxide. It may help us to someday understand what goes wrong in diseases that affect cognitive processing, such as attention deficit disorder or schizophrenia, and it adds to our fundamental understanding of how we perceive the world around us."
People have been comparing brains to computers almost as long as they have been comparing computers to brains. The Computational Theory of Mind looks at the mind (the brain's software as some have described it) in pretty a logical way, not too far away from computational reasoning. These comparisons are useful for understanding larger concepts but they generally fall apart when you get to the nuts and bolts of it. For example, the brain processes many shades of grey instead of a computer's binary perception. Neural networks and, to a lessor extent, quantum computing seek to emulate some of the processes of the brain.
On an aside, if you are interested in learning more about machine intelegence, I highly recomend reading Ray Kurzweil's books.
Research abstract (Score:5, Informative)
Diurnal gene expression patterns of T-type calcium channels and their modulation by ethanol [sciencedirect.com]
The transient (T-type) calcium channel participates in the generation of normal brain rhythms as well as abnormal rhythms associated with a range of neurological disorders. There are three different isoforms of T-type channels and all are particularly enriched in the thalamus, which is involved in generating many of these rhythms. We report a novel means of T-type channel regulation in the thalamus that involves diurnal regulation of gene expression. Using real time polymerase chain reaction we detected a diurnal pattern of gene expression for all T-type channel transcripts. The peak of gene expression for the CaV3.1 transcript occurred close to the transition from active to inactive (sleep) states, while expression for both CaV3.2 and CaV3.3 peaked near the transition of inactive to active phase. We assessed the effect of chronic consumption of ethanol on these gene expression patterns by examining thalamic tissues of ethanol-consuming cohorts that were housed with the controls, but which received ethanol in the form of a liquid diet. Ethanol consumption resulted in a significant shift of peak gene expression of approximately 5 h for CaV3.2 toward the normally active phase of the mice, as well as increasing the overall gene expression levels by approximately 1.7-fold. Peak gene expression was significantly increased for both CaV3.2 and CaV3.3. Measurements of CaV3.3 protein expression reflected increases in gene expression due to ethanol. Our results illustrate a novel regulatory mechanism for T-type calcium channels that is consistent with their important role in generating thalamocortical sleep rhythms, and suggests that alterations in the pattern of gene expression of these channels could contribute to the disruption of normal sleep by ethanol.
Curiously, I get the impression that the emphasis of the research is somewhat different from what was emphasized in the popular-press article.
Re:Research abstract (Score:5, Informative)
The paper you link is a different one. This is the actual paper:
Alexander GM, Kurukulasuriya NC, Mu J, Godwin DW. Cortical feedback to the thalamus is selectively enhanced by nitric oxide. Neuroscience. 2006 Jul 28 http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=p ubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=168 76956&query_hl=12&itool=pubmed_docsum [nih.gov]
Indeed the area they study is somewhat mysterious: The thalamus provides separate communication channels for essentially all sensory information from the sensory organs (e.g. eyes) to the cerebral cortex. However, unlike most brain areas it appears that there is no transformation going on in the thalamus. So if there is no computation, it must be a relay! As much as much most neuroscientist find the idea of pure "relay" unsatisfactory we simply have no evidence for anything beyond it. Hence all the speculation. Unfortunately, the present paper sheds no light onto the thalamus mystery. The authos cut a slice out of a brain and study in isolation. Clearly you won't get much functional information about what's actually going on in this way. Then the authors dump a drug onto the slice to show that it differentially turns up the gain of one input and turns down the gain of another one. Nice, but we don't know if this is actually going on in the brain or how this chemical would get there. If --as the journalists claim-- this finding were to transform our ideas about the thalamus then it probably wouldn't be published in a third tier journal like 'Neuroscience'.
So much for science journalisms.
-phystor-
Re:Wrong wrong wrong (Score:3, Informative)
Which is why I think Ps. Cubensis and Ps. Mexicana mushrooms are so much fun.
Re:nitric oxide's (Score:1, Informative)