Vertebrate Physiology

“Researchers at Stanford engineered mice to carry light-sensitive proteins in the brain’s reward center, which responds to drugs of abuse. Using pulses of light delivered directly to the brain, researchers were able to induce a druglike state, ultimately conditioning the mice to behave like drug-addicted animals.” To read the rest of the article click here.

Summer love is in the air.

When Bob went out to the beach, he couldn’t stop oogling Hilda in the yellow polka dot bikini. They were both attending a steamy neurobiology conference. With his heart beating rapidly, he decided to ask her out to a gourmet meal at Chipotle. Lucky for Bob, she was hungry after surfing all day so she said “sure-rritos.” Hilda’s puns only reinforced Bob’s initial attraction. “What a woman!” Bob thought. They walked to his car. She reached over to hold his hand, at which point his stomach flipped with nervousness. They both smiled.

He leaned over and whispered
“Hilda, it’s about time I let you know how I feel. You light up my ventral tegmental area, nucleus accumbens, ventral pallidum and raphe nuclei.”
Hilda was so touched, she screamed out “I love you too Bob!”

Your brain has a circuit for snuggling with schnookums. You might have expected that being in love activates a reward pathway.

But here is one surprising detail: heartache is akin to “craving”…the kind of craving seen in drug addiction.

Some of you have mastered the art of cramming for exams. But what really happens when we store a thought for a very short period of time? What are memories made of? We’ve come a long way in our understanding since Dean Martin’s 1955 hit song. After looking at single neurons in the prefrontal cortex of mice, researchers at UT Southwestern have identified a specific receptor that drives short-term memory storage. Even more interestingly, they used dopamine and cocaine to simulate the effects of addiction on momentary recall. Curious about what happened? This article gives a great summary of their recently published findings in Nature Neuroscience.

Speaking of memory…do you remember our lecture on the hippocampus? Another study at the University of California looked at long-term recall and the involvement of specific brain structures. In light of what we learned in class, try to reason through their results.

One powerful aspect of neurobiology is the wide range of approaches we can use to answer key questions. Both of these research teams wondered “how do we store memories?” While the first study chose to look at single cells, the latter looked at whole brains. Integrating both micro and macro results gives us a more accurate depiction of how our brains are processing information.

This is yet another great piece on the topic of memory. A group of German researchers noticed that particular patterns of brain waves predict which memories you will remember, and which you will forget.

Do these lines look like they extend away from you at different angles? Actually, they’re exactly the same. You brain is fooling you…again! For more information and a few other examples of this illusion, click here.

Still trust your perception? Maybe this will change your mind. Here is the 2009 winner of the Best Visual Illusion of the Year Contest.

The placebo effect has been observed for centuries. Patients given nothing more than sugar pills are able to alleviate their own pain, anxiety and depression. In one case, a terminal cancer patient shrunk his own tumors when he believed in the power of a sham treatment.

This is a very well-written article that links the placebo effect with conditioning. Just like Pavlov’s dogs were conditioned to salivate at the ring of a bell, your immune system can be conditioned to start the healing process at the sight of a doctor’s coat.

Has someone just been watching too many sci-fi movies on Hulu? Doctors at Geneva University Hospital disagree. This is a special case of a supernumerary phantom limb. After suffering a stroke, the 64-year old woman says she can see and feel the “presence of a pale, milky-white and translucent third arm.” More surprisingly, she even uses it to scratch other parts of her body! When neurologists gave her an MRI, they found activity in her motor and visual cortices. Even though the arm does not physically exist, her brain responds as if it’s really there.

Just for fun…

Did you know that your brain is made up of more than just neurons? In reality, it’s a mix of many different types of cells. Glial (housekeeper) cells are the most common cell type in the CNS. These have endless functions, from providing nutrients, to repairing damaged tissue, to physically keeping neurons in place.

It would be an oversimplification to think that neurons get all the action. Sure, they’re the jocks of your brain. But don’t overlook the guys in the background. You know…the geeky glial cells. They can surprise you! Research on these supporting cells is turning up some interesting results. One particularly cool discovery: when it comes to lulling you to sleep after a long day, astrocytic glial cells steal the spotlight.

CBS is not typically a good source for science articles, but this is a very nice read on the science of sleep. They mention some of the aspects that we talked about in class- the need for sleep, how it affects learning and memory, and perhaps most importantly, the link between sleep and attention. People getting the shortened sleeps that the average college student experiences would drift into microsleeps (a few seconds)– enough to drive off a road. Something to think about when driving home after a week of studying for finals.

A recent article in Scientific American describes one of the treatments for patients experiencing phantom limb pain. One solution mentioned was to thrust a screw driver into the apparent trouble spot. The amputee would place his prosthetic leg where his own leg used to be, and stab at it with his screwdriver. The claim is that as long as he could see this, the pain would be relieved.
There are other solutions mentioned here, in particular, the use of mirrors.

Here is a short NPR broadcast in which AJ describes her experiences with her near “perfect” memory. She can remember near everything that has happened to her, but has a poor capacity to remember facts and even historical events. A key component to her memory is the emotional content in her memories, and recall of those memories.
In the meantime, here is a link to a National Geographic blurb on memory that is good reading.