For this week’s in-class “NeuroSlam” I spoke about a paper on mirror-touch synesthesia– a condition in which an individual reports feeling an actual tactile sensation in response to seeing someone else touched. For example, this synesthete would feel as if someone touched their arm if they saw someone touching another’s arm. Inspired by an fMRI of a mirror-touch synesthete that showed hyperactivity of mirror-touch network neurons (mirror neurons we all have in the somatosensory cortex, premotor cortex, and parts of the temporal lobe that fire in response to touch and viewing touch), researchers Micheal J Banissy and Jamie Ward wanted to study empathy in mirror-touch synesthetes as empathy is believed to be related to mirror neurons.

In addition to providing evidence for mirror-touch synesthetes experiencing a synesthesia very similar to actual touch, Banissy and Ward measured empathy in these individuals using a psychological test. They reported that synesthetes scored much higher in the “emotional reactivity” subset of the empathy quotient but not in “cognitive empathy” or “social skills.” This supports the theory that mirror neurons do play a role in empathy as well as the idea that empathy is a complex neurological process that can’t be be wholly described in one neural network.

Banissy, M.J., Ward, J. Mirror-touch synesthesia is linked with empathy. Nature Neuroscience 10, 815 – 816 (2007)
Published online: 17 June 2007 | doi:10.1038/nn1926

[Read more…]

While reading the book Time, Love, Memory I ran across the phrase, time-blind. It was used in the context of saying that without clock genes, genes that define our circadian rythm, we would be time-blind. Is this possible, are there people who have no concept of the passage of time?

Tomorrow is the big day. Much to my liver’s dismay, I’m turning 21, so I thought it would be appropriate to discuss the effects on alcohol on the brain in this post.

I searched through article databases reading abstracts about how alcohol shrinks the brain, depletes white mater, inhibits growth of and destroys neurons etc…, until I stumbled on a study that examined acutely intoxicated rat brains. Over hour intervals after alcohol exposure, researchers were able to document neuroplastic changes involving tyrosine hydroxylase, proenkephalin and cannabinoid CB(1) receptor gene expressions. That alcohol alters receptor expression in neurons is a sobering thought. It turns “I only like you when I’m drunk,” into “I only like you when I slowly alter the chemical and physical composition of my brain.” The researchers hypothesize this may play a role in addiction and the immediate feel-good affects of alcohol.

I thought about volunteering my services if the authors ever wished to document their findings in human subjects until I learned I’d have to consume 3g/kg of alcohol (which works out to be about 18 standard drinks for me… a bit too life-threatening for comfort) and that the rats were killed by decapitation (I’m attached to my head). I guess the more I think about it the less I’m interested in incurring a great deal of brain damage this weekend; I’m not sure I could make it through the rest of Neurobio firing on a few less cylinders. I might just take my shiny new ID down to the grocery store and pick me up some O’Doul’s.

Reference: Oliva JM, Ortiz S, Pérez-Rial S, Manzanares J.Time dependent alterations on tyrosine hydroxylase, opioid and cannabinoid CB(1) receptor gene expressions after acute ethanol administration in the rat brain. Eur Neuropsychopharmacol. 2007 Oct 24; [Epub ahead of print

Hi guys and gals, it’s been awhile since my last entry. Last week kept me very busy. In the midst of my late nights typing, I learned some fun things about chloride channels (for one of PZ’s exams.) I learned about their job of regulating cell volume and an appropriate cell-membrane charge.

One thing piqued my curiosity. The cell exterior has roughly 5 milliMolar [chloride – ], while the interior has 125 Molar [chloride – ]. The interior also has a negative charge. Despite all of those factors, the articles I read seemed to say that chloride would diffuse inward if the channels were to open. That is very weird, unless I’m missing something. Is there some very high concentration of a similar ion on the outside that is high enough to send chloride scurrying inward? If anyone has experience in this area, please chime in.

My next lecture in my neurobiology course is going to be about metabotropic receptors and how modulating internal cGMP levels is one way neuronal activity can be affected. I was planning to use the eye as an example of this process — but now Revere has inspired me to add a bit about the penis and viagra to the lecture. Here at UMM, we’re all about giving students information they can use.

I read an interesting article in the New Yorker the other day. It followed the research of neuroscientist Adrian Owen and his work on patients in vegetative states. In some patients, when he gave the verbal command to “imagine you are playing tennis,” their brain regions lit up on an fMRI indistinguishably from your average walking, talking, and recognizably conscious human being asked to perform the same task. Moreover, the patients were able to sustain this activity (so presumably the tennis imagination) for over thirty seconds suggesting some degree of focus.

The article goes on to discuss implications. It points out that Owen only found a few patients in vegetative states with this ability. Others were not at all responsive. It was a pretty good indication that the patients who were able to follow his command had some sort of retention of cognition that others did not. However, they were not diagnosed incorrectly. The question then becomes: if the criteria by which physicians diagnose vegetative states applied to these patients, do we need a better test?

In biochemistry this past week we have been learning about the immune system. This lead me to do a google scholar search on neurobiological diseases. This search turned up a large number of articles on Parkinson’s disease, Alzheimer’s, and Huntington’s disease, which casused me to form the hypothesis that neurological disorders onset are typically later in life (post 40’s). Is my hypothesis way of mark or is there some truth to it?

As I pondered what to post about on Pharyngula this week my thoughts immediately turned to football *wink* …which got me thinking spinal cord injuries (and no… not in the context of malice toward Drew Brees), which got me thinking of last year’s Distinguished Alumni speaker, physiatrist (and poet!) Jon Mukland ’80.

Dr. Mukland presented his research on the development of the BrainGate Neural Interface System– a program designed to interface victims of spinal cord injury with a computer. A silicon chip implanted in the motor cortex uses feedback from hundreds of probes to map electrical activity patterns associated with certain motor tasks. For example, if the patient is asked to imagine they are moving a computer screen cursor to the left, the implant records the pattern of electrical activity associated with that function. A computer is programed to interpret that activity and move the cursor left when it receives that input again. This is duplicated for other kinds of movement. The result is that a the patient is able to manipulate a computer cursor with his or her mind.

Dr. Mukland went on the describe the benefits of this system. The ability to manipulate a cursor independently, even in limited ways, opens up a host of quality of life opportunities for paralysis victims. Computer programs could be designed to allow patients to turn on appliances, use the internet, or communicate electronically. As the technology improves, the implications for improved quality of life increase dramatically.

I’ve never been so proud to be a UMMer :)

While I am a college student and enjoy the occasional alcoholic beverage, I have never tried to get any other species drunk. Until now. As some of my classmates may have previously stated, we have to design and implement some sort of neurobiological experiment. I will be testing the alcohol tollerace of zebra fish, testing reactions and behaviors after cronic exposure to various concentrations of alcohol. Perhaps after this experiment I will test my own reactions and behaviors after being constantly smashed for two weeks.