I've had friends who report that they are "addicted" to running or cycling or some other fairly intense exercise; this mouse study found that certain mice do show activation in regions of the brain affected by cocaine or nicotine, only their stimulus is running. And I think that 6 _miles_ a day is pretty darned impressive for such a little crittur!
http://my.webmd.com/content/Article/78/95585.htm?printing=true "...In this study, researchers bred exercise-loving mice -- that is, mice with a genetic predisposition to run longer distances on the wheel, explains researcher Justin S. Rhodes, PhD, a zoologist with the University of Wisconsin-Madison...For six days, both the specially bred, exercise-compelled mice and the control mice ran in their cages -- on their wheels -- as much as they wanted. Researchers documented the distances that each covered. The compulsive mice covered more ground than the control mice, although each group ran for the same time period, he reports. On the sixth day, the compulsive mice averaged about 6 miles, while control mice logged about 2 miles. "On the seventh day*, half the mice in each group were blocked from using their wheels. The other half in each group got free-running time as usual. As the mice reached their running peak, about five hours later, researchers looked at their brain activity. They also looked at brain activity of mice blocked from running. The specially bred mice had extremely high levels of brain activity in certain regions -- the same regions that become activated when rats can't get their daily fix of cocaine, morphine, alcohol, or nicotine, Rhodes explains..." This tiny human study utilized MRI imaging (yo, Bob!) to look at brain activity while looking at cartoons: http://my.webmd.com/content/Article/77/95575.htm?printing=true "...Although researchers have long known that a good sense of humor has many healthy benefits, relatively little is known about how humor is handled by the brain. But a new study shows that humor may give people a natural high by activating the same reward centers in the brain that have previously been linked with happiness and drug-induced euphoria. "In the study, researchers used magnetic resonance imaging (MRI) to study how the brains of 16 healthy adults responded to funny vs. non-funny cartoons. The brain scans were used to detect areas of the brain that were activated when the subject found the cartoon funny. The study showed that in addition to activating areas of the brain involved in language processing, humor also stimulated regions of the brain known as reward centers, such as the amygdala, which releases dopamine. Dopamine is a powerful chemical that plays a vital role in the brain's pleasure and reward system..." This article isn't in PubMed yet, but here is one that is [this ought to be read thinking "Data's voice"]: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12902310&dopt=Abstract "...To summarize the results of many studies, the expression of laughter seems to depend on two partially independent neuronal pathways. The first of these, an 'involuntary' or 'emotionally driven' system, involves the amygdala, thalamic/hypo- and subthalamic areas and the dorsal/tegmental brainstem. The second, 'voluntary' system originates in the premotor/frontal opercular areas and leads through the motor cortex and pyramidal tract to the ventral brainstem. These systems and the laughter response appear to be coordinated by a laughter-coordinating centre in the dorsal upper pons. Analyses of the cerebral correlates of humour have been impeded by a lack of consensus among psychologists on exactly what humour is, and of what essential components it consists..." Insert: "Humor - it is a difficult concept." Lt. Saavik to Cap'n Kirk, IIRC. :) "...For the perception of humour (and depending on the type of humour involved, its mode of transmission, etc.) the right frontal cortex, the medial ventral prefrontal cortex, the right and left posterior (middle and inferior) temporal regions and possibly the cerebellum seem to be involved to varying degrees. An attempt has been made to be as thorough as possible in documenting the foundations upon which these burgeoning areas of research have been based..." Elmer And Homer And Buggs, Oh My! Maru :) *No kidding? ;) __________________________________ Do you Yahoo!? Free Pop-Up Blocker - Get it now http://companion.yahoo.com/ _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
