Mr. Me

As far as I know each sensory system has its own map of one sort or another (except smell and taste, there is no real map for these senses). But things get much more interesting in areas of the where these maps begin to interact. A lot of work has been done on a structure called the Tectum (also known as the corpora quadrigemina in some older text books). In the tectum maps of visual and auditory space are directly on top of one another and are synchronized. That is point A in visual space is represented by a small patch of tectal space that also represents point A in auditory space. Most of this work has been done in barn owls because of their very strong abilities to localize sounds in visual space (I think they call this cross-modal processing). I don’t know if you are a university student, but if you are or are near a university you should check out a copy of Principles of Neural Science by E. Kandel and J. Schwartz for more of the technical info on this kind of stuff. If you are really interested in neuroscience as a subject for college or graduate school I highly recommend you read “The Man Who Mistook his Wife for a Hat” By O. Sacks and “Time Love Memory” by J. Weiner. Both of these were instrumental in convincing me to study neuroscience. They are also great reads for anyone interested in how the brain works. I hope you get a good grade on your paper

There are two ways you could address this question depending on what exactly was asked. The first way to answer this question would be a discussion of the fact that different parts of the brain do different things. You could talk about a map of the brain based on which parts of the brain do what jobs. For instance, the very back of the brain, the occipital lobe, is where input from the eyes is processed. The sense of touch takes place in the parietal lobe…you could then draw a “map” of the brain where you assign a color to a function (say blue for vision) and color the portion of the brain responsible for a function in the corresponding color. Check out Brain Facts from the Society for Neuroscience (the link is below) for good information on the functional specialization of the brain. The second way you could answer this question would be to talk about the map in the brain of the body and space. The map of the body is the best worked out so I would start here. In the portion of the brain that detects touch to the skin (primary somatosensory cortex) there is a very good neural “map” of the body. This is called the homunculus (little man). Basically, very small portions of the brain have been shown to receive sensory information from very specific parts of the body. Here is a link to a few resources that do a fairly good job of explaining this. http://faculty.washington.edu/chudler/flash/hom.html (this entire site is very useful for basic information on the brain. The main page is at http://faculty.washington.edu/chudler/introb.html ) Check out Brain Facts from the Society for Neuroscience ( http://web.sfn.org/content/Publications/BrainFacts/index.html ) This book is a good primer on the brain. If you want more advanced information look for a basic textbook like “The Human Brain: An Introduction to its Functional Anatomy” . This is one of the books commonly used in college neuroscience classes and it is very good.

Some researchers do use strong magnetic fields to stimulate very small regions of the brain. This technique, known as Trans-cranial Magnetic Stimulation (TMS), uses a strong, focused magnetic field to activate certain cortical circuits. When the magnetic pulse is applied involuntary movements can be elicited from test subjects (when the magnet is positioned over motor cortex). I have only seen these experiments done with motor cortex but it could be used on any part of the nervous system. Edit:Magnetic pulses elicit neuronal activity by creating currents with all ions present in the nervous system, but potassium and sodium do most of the work for generating action potentials.

I thought the transcription/CREB step was when a memory was formed? As for what forgetting is, well you would have to know what memory is and that is not entirely worked out. Different types of memory happen in different parts of the brain, so what exactly causes you to forget someone’s name may not be the same as what causes you to forget where an old friend lives. Memory is a little better understood in invertebrates, specifically Aplysia californica. In aplysia memory formation is directly related to increases in the strength of specific synapses. What we would term "forgetting" is related to decreased strength of these same synapses. So if the same rules apply to humans (hahaha) then decreased synaptic fidelity in those synapses coding a memory would be the cause of forgetting (note that this is wild conjecture). This loss of synaptic fidelity could have any number of causes. The neuron could die (Alzheimer's, CJD, Dementia...), synapses that are rarely used may be removed (see Hebb's postulate), or the little elf just took a nap, there is really no telling.

amyloid beta is in plaques, but the primary component is a protein called Tau. There are lots of other proteins in the plaques too like ubiquitin and heat-shock proteins, but A-beta has gotten most of the attention in the past few years. As for what crosses the BBB, dont forget anything that is lipid soluble will cross, they are just cells after all. The ones that come to mind are steroids, most ilicit drugs, alcohol and lots more.

Why would you propose this? Edit: I did not mean to say grasshopper, I should have said Fruit fly.