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Monday, 25 June 2012
A Whole Hippocampus Reveals Its Secrets

Theta-waveSome major scientific discoveries are the result not so much of a particular experiment as of the lengthy efforts to develop the protocol used in it. Such was the case for a study that Sylvain Williams published in Nature Neuroscience in November 2009. Williams and his team had worked for years to refine the method used in this study to record neuronal activity in a whole rat hippocampus preserved in vitro.

The more traditional method, in which researchers record the activity of neurons in a thin slice of hippocampal tissue, is much simpler but necessarily destroys huge numbers of neural circuits internal to the hippocampus—for example, all of the axons that pass through the slice perpendicularly.

It should be no surprise, then, that the very first recordings that Williams and his team made with a whole hippocampus successfully dispelled a misconception that had been accepted for many decades. The theta rhythm—the major rhythmic pattern of discharge of the neurons of the hippocampus—does not necessarily come from an external structure (the septum), as had always been believed, but can come from the hippocampus itself!

In other words, this experiment clearly demonstrated something that hundreds of previous studies with hippocampal slices had failed to show. Given how critically important theta rhythms are for learning and memory, this study’s finding that these rhythms can emerge endogenously in the hippocampus, and specifically in its CA1 sub-region, raises some interesting questions for the future. For example, what kinds of interneurons in CA1 are involved in generating theta rhythms, and how are these rhythms integrated with the other rhythms observed in the cortex, such as gamma rhythms?

i_lien Researchers at the Douglas redefine the role of a region of the brain associated with organizing memory
a_exp Hippocampal theta rhythms follow the beat of their own drum + Self-generated theta oscillations in the hippocampus

Memory and the Brain | 1 comment


One comment at; “A Whole Hippocampus Reveals Its Secrets”

  1. Maryono says:

    What are you thinking. On PBC which did a proargm on the Hippocampus, the proargm introduced that the Hippocampus is increased with stress. That is one thing about your article that made me go What! I am sure that my interest in the Hippoampus will be made more memrable because of my age and my new career. The average age for the type of work I am doing is 33 and I am well into my 50 s my having to compete these co workers. What little I know of Hipposcampu and the type of work I do ( lost of proargms, computer inputs and extracting information from these 100 + proargms) information over load. I watch as my senior workers who have worked 30 40 years in the field, have a wealth of knowledge and have a feel for the proargms and the type of information that computer proargm needs to process the information. I find that at 50 this job is exciting and fun. Two reasons one there a people involved and the learning of extrating information.Your take on religion decreases the size of rhe Hippocampus just will not hold water. Seek out more information from PBS and than tell us what you think.

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