Patrick Lockberby - Artice Ice Update - March 2011

Hmmm, this is not good:

"Arctic sea ice extent for February 2011 tied with February 2005 as the lowest recorded in the satellite record." 

Interestingly, 2005 was a year of very high sunspot activity and this year sunspot activity is also high.

Apocalypse 2012: An Investigation into Civilisation's End

Book Review: Apocalypse 2012: An Investigation into Civilisation's End.
Lawrence E. Joseph.
Broadway Books, New York, 2007

I find this a perplexing text. So many new ideas from so many different sources. The author traveled around the world to interview scientists, psychics, Mayan ancestors, and various individuals ranging from shamans to mystics. It would take me far too long to investigate all the claims in this text. Other reviews on this text indicated a mixture of respect and caution in judging this text. There are errors, there must be errors, but there is enough solid material in this text to leave me interested.

The first two thirds of the text are an entertaining read. The author employs an easy reading style that doesn't become too technical and bogged down. Thankfully the text is not alarmist or written as if being some great document of revelation. He quotes the relevant individuals, he puts forward their ideas clearly and without editorialising their statements.

A Counter Intuitive Study on Longevity

There is no easy way to establish strategies for living a long life. This news release adds to our confusion. I proffer the following cautions:

1. This study contradicts many other studies. When that occurs don't accept the study at face value, it needs to be subject to critical review by many people, and believe me that is far superior to peer review! 
2. This study is relying on data gathered a very long time ago, when experimental methods were much less refined than today. 
3. It relates to analysis of "more than 1500 bright children". Small sample, and just what do they mean by "bright". 

The new release does not point to a published paper, the results are being published in book form. I would much prefer that they first publish a series of papers then publish their book. By publishing the book first they are putting out a view on longevity that has not been subject to (1) above.

For myself at least I have to disregard the claims of this news article. Yes I can see elements that I find plausible but in the absence of a series of papers that have been subject to critical review and discussion by a wide range of people it is virtually impossible to know if all their conclusions are valid.

There is a good lesson here in relation to health news. There are also sorts of claims being made about the secrets to longevity. There are no secrets, we're still learning, but obviously a good deal of common sense goes a very long way. Eat well, exercise regularly, and don't go looking for fountains of longevity.

The Brain's "Reward" Centre Also Responds to Fear

One of my pet hates in neuroscience is the propensity to attribute highly specialised functions to currently identified brain regions. If only it were that simple. This study, remarkable in its detailed analysis, again reminds us that the brain is not only a wonderful thing but an incredibly wonderfully complex thing.

It has long been known and studied that the ventral tegmental area(VTA), a rather small nucleus in the midbrain, is very much involved in "reward" processes. Illicit drug use very often involves the VTA dopamine neurons becoming rather active. Even marijuana, who some claim is not addictive, will involve activation of these neurons.  Note though that the abstract refers to a specific location in the VTA - the posterior region. These nuances in how these "cerebral modules" respond needs to be kept in mind. For example, we often read that the amygdala is a "fear center". For example, consider this recent news release which appears counter intuitive. In that news release, the so-called "fear centre" - amygdala appears to play a role in reducing anxiety. Note though that is very misleading to refer to a "fear centre". Neurons don't experience fear, we do! As the linked Wiki article states, the amygdala can be subdivided into many regions. For an excellent introduction to the amygdala, try reading "The Emotional Brain" by Joseph LeDoux, who pioneered important research into this region.

This study identified 3 types of dopamine neurons in the VTA. While Type 1 and Type 2 neurons did not respond to fearful events, actually decreasing their firing rates but with a rebound at the cessation of the fearful event, Type 3 neurons increased their firing rate. Thus ...

Moreover, the excitation duration of type-3 dopaminergic-like neurons also correlated with the duration of fearful events.

However I am puzzled by this and have to wonder if it points to error in identifying these Type 3 neurons:

Our pharmacological results revealed that the vast majority (96%; 23/24) of type-1 and type-2 putative dopamine neurons were significantly suppressed, while surprisingly the type-3 neurons (n = 9) otherwise showed excitation by apomorphine

The bods then went onto to test how these neurons responded to both positive and aversive events:

Neuronal activity recordings in these conditioned mice (after 1-week training) revealed that VTA putative dopamine neurons responded significantly to the conditioned tone that predicted a sugar pellet in the reward chamber (Figure 6D, left panel). Interestingly, the same VTA neurons also responded reliably to the same conditioned tone when it predicted free fall in the free fall chamber (Figure 6D, middle panel). When the same conditioned tone was delivered to mice in a neutral chamber that was not associated with any event, it did not produce significant changes in firing.

What this suggests is that these neurons in the VTA are not only responding to reward or adversity but also to the expectation that something in the environment is about to change. It would be interesting to see if any of these neurons would respond to innocuous environmental contingencies. I have a sneaking impression that what we are witnessing here is a general alerting function to a change in the environment, with different neurons providing information about the nature of the environmental change. This information is highlighted by a sentence in the closing paragraph of the paper:

These putative dopamine neurons respond to different negative events in a similar manner and more importantly, their temporal durations of dynamic firing changes are proportional to the durations of the fearful events.

Our Vagabond Minds

Be warned, I'm calling shenanigans on this one.

ScienceDaily (Nov. 11, 2010) — People spend 46.9 percent of their waking hours thinking about something other than what they're doing, and this mind-wandering typically makes them unhappy. So says a study that used an iPhone web app to gather 250,000 data points on subjects' thoughts, feelings, and actions as they went about their lives.

Nature Beats Monsanto

In genetics there has been of late considerable interest in a phenomenon known as "horizontal gene transfer". This news release takes that concept to new heights.

ScienceDaily (Nov. 8, 2010) — Genetically modified plants can come about by natural means. A research group at Lund University in Sweden has described the details of such an event among higher plants. It is likely that the gene transfer was mediated by a parasite or a pathogen.

One of the consistent trends of late has been that the idea of "gene transfer" needs to widened because there is increasing evidence that genes are much mobile than we once believed. As it happens just last night I caught some snippets of a documentary about viruses. I was amazed to see that the HINI virus was composed of genes from a number of sources.

Even more amazing was that in a cell infected with two viruses the constant replication, with a relatively high error rate, allowed a mixing and matching of the two viral genomes. Now when you consider the extremely high replication rates that can occur you realise that viruses are emulating a very powerful mathematical strategy against our immune responses.

There was some uproar about the responses to the viral outbreaks in recent years. The strategy is based on the obvious fact when a viral outbreak occurs containment must be the first priority. In many cases we won't have time to determine just how dangerous the pathogen is. While immunology is making some great strides keep in mind that the task is almost herculean in its objectives. So be kind to immunologists, they are very important people.

In this news release the mode of gene transfer was quite odd. About 700,000 years ago part of a  chromosome was incorporated into the genome of another plant, the hypothesis this was probably mediated by a pathogen or sap sucking parasite. It has long been known that bacteria can share their genetic material, and over recent years the Weismann Barrier has been breached on numerous occasions, and we have a much better appreciation of just how mobile genes can be. In that light the diversity of Life is not so surprising.

The Bright Side of the Fish Oil Component - DHA

This news release from ScienceDaily directly contradicts the findings of just a a few weeks ago. In my earlier post I was addressing research which indicated DHA can induce a "Th 1 type mediated inflammatory response". In relation to Stroke the conventional wisdom quite literally screams that such a response is the very last thing one would want to treat stroke yet now we have a report asserting remarkable efficacy of DHA in ameliorating damage from stroke.

ScienceDaily (2010-11-08) -- A new study shows that a component of fish oil is a powerful therapeutic agent that can protect brain tissue in a model of stroke, even when treatment is delayed by five hours. These findings not only target a new stroke treatment approach, but also provide vital information about the length of the therapeutic window.

For those so interested you can download the full article at this link. Bit of surprise, Springerlink usually doesn't give stuff away and I suspect this is a website error so be quick!

The findings of this study are remarkable:

Black Man Wins Genius Award

A friend of mine sent me this clip of John Dabiri. Great clip. If you have ever wondered what is the point of studying jellyfish movement and other such seemingly obscure research watch this clip. For some background on Dabiri you can read the following links:

http://dabiri.caltech.edu/people/dabiri.html

Microglia as Regulators of Neural Transmission

This study, freely available here(4.61MB), has some striking implications. These are listed below. The Science Daily news release can read here. Microglia are typically perceived as the immune cells of the CNS but this study builds on former studies all pointing to the possibility that our current understanding about neural transmission and memory is too constrained. This present study indicates:

• Microglia regulate the fate the synapses
• Microglia are constantly on the move and at a rapid pace.
• Microglia may be regulating memory consolidation.
• Our conceptual separation of immune processes and neural transmission is a fundamental error.

The Business of Intelligence

A report from Science Daily highlights the problems of modern intelligence research:

ScienceDaily (2010-10-30) -- General intelligence is not enough. Practical intelligence can mean the difference between entrepreneurial success or failure. Psychologists have identified multiple kinds of intelligence, but a new study has found one -- practical intelligence -- to be an indicator of likely entrepreneurial success.

Charles Spearman created the concept of the "g factor", a general intelligence that underlies the styles of intelligence measured in iq tests. I'll stay away from the whole issue of iq tests, I have two professional friends with a behaviorist orientation and they seem to hate IQ concept with a vengeance. I think I know what they are getting at but I still maintain that IQ as a metric is fine but has a theoretical construct or as data for the same it is useless. The history of the debate about IQ is in itself instructive that when dealing with the question of intelligence we are still very much in the dark. At the end of this post I will reference a research item that demonstrates we may have absolutely no idea about the true basis of intelligence.