Yearbook 06-07


Johannes Richter
Home Institution Georg August Universität Göttingen Host Institution(s) Yale University School of Medicine, New Haven Mentors: Wei R. Chen, Ph.D., and Gordon M. Shepherd, M.D., Ph.D. E-Mail: j-richter@web.de
Research Topic see Abstract
Personal Reactions to the U.S. Experience I had a very warm welcome at the lab and was given great support and freedom for my research. During the first weeks I was hosted by a German postdoc, who gave me valuable advice while settling in at Yale and enough time to look for an own place to stay. I decided on a place close to the Medical School at Harkness Hall, the medical students’ dormitory. Yale University has a high percentage of international students and scientists, and takes special care of them. I remember being invited by the university to join a local family on Thanks-giving, it was a very nice experience to be part of an American family on such a day. New Haven has two symphony orchestras, several theatres, and hosts innumerable college sporting events. There are also plenty of nice outdoor places to visit around New Haven, I liked it very much driving along the shoreside up to Hammonasset Beach, Newport, Cape Cod, and Boston this Spring. It is also a pleasure to go to New York City every once in a while, it takes less than two hours to get there and I enjoyed going to concerts at the Lincoln Center and for a NY Knicks basketball game at the Madison Square Garden.
Greatest Difficulties Encountered Luckily, I have not encountered any notable difficulties while preparing my stay and after arriving in New Haven. With assistance from Yale University, getting the visa was smooth and swift. It also helped not to hesitate to make phone calls and talk to the people processing my invitation forms to make sure they had all the documents and information needed. I got my visa interview appointment four days after calling, and found my passport with visa three working days after the interview in my mail box. The interview itself was a matter of three minutes.
Most humorous incident I remember having great fun on the Yale Ski Trip in Vermont in February, while sharing a condo with five other graduate students and postdocs. Sure enough, during that weekend we had some very funny moments. There I also met, and back in New Haven made friends with two British people from Oxford who just arrived in at Yale. One of them made such funny jokes that all people at the table just could not resist laughing.
Helpful Hints for Future Students Finding a suitable lab for the intended research project and getting an invitation from the host university might take several months, so it appears crucial to apply early for a research position. It might be also easier to be accepted into a high-profile lab for a specific time period just by applying well ahead of time rather than on short notice.If the intended exchange year is well ahead, completing a short research project or elective rotations in the U.S. prior to the exchange year may give one valuable insight into academia here and the opportunity to prove one’s capabilities in the setting of a hospital or lab here. In addition, having a reference in the U.S. as well as a letter of recommendation after this brief stay might be greatly appreciated later on by the people deciding on one’s research project and scholarship applications. While planning my research projects at Yale and Stanford, I received excellent advice from current and former DFG scholarship holders (www.dfg.de/wissenschaftliche_karriere/forum/forum_auslandsstipendiaten/). Usually, the Office of International Students and Scholars (OISS) of a given university provides useful and concise information for foreign students arriving in the U.S. For Yale there is an excellent handbook available online www.oiss.yale.edu/students/handbook.htm) While looking for a health plan, the Victoria Versicherung package of the DAAD might be a useful starting point: http://usa.fh-hannover.de/versicherung.htm
	New Haven - Lighthouse Park
	View on New Haven from Eastrock Park
	Yale University School of Medicine - Main Entrance
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Abstract on Research Topic
Training-induced plasticity of odorant maps in the olfactory bulb

Authors:
Richter JK, Fletcher ML, Chen WR, and Shepherd GM

Institution:
Yale University School of Medicine, Department of Neurobiology, New Haven, CT

Introduction:
Odorants are encoded in the olfactory bulb as networks of spatially distributed clusters of active neurons (glomeruli), referred to as odorant maps. The aim of this study is to investigate if training is able to permanently alter these maps indicating perceptual learning and memory in the olfactory bulb.

Materials and Methods:
The mice employed in this research project express an intrinsic Calcium indicator (G-CaMP2) under the Kv3.1 potassium channel promoter. This allows for chronic in vivo Ca2+-imaging without craniotomy. In each mouse the bone covering the olfactory bulbs was thinned with a dental drill such as to become transparent when covered with saline, and subsequently processed to a chronic imaging window. Odor-evoked glomerular activity maps were acquired using a 10x immersion objective (Olympus), CCD-camera (Redshirt).and Neuroplex acquisition software. Data analysis was performed in Matlab.
Odor deprived mice of 2 to3 months of age were anesthetized with Pentobarbital, fixed in a custom-made stereotaxis without earbars (Narishige and Yale University Instrument Design) and presented with methyl valerate as well as control odorants. Imaging was performed on days 1 and 4 to investigate the native odor maps and as a proof of the map stability across days. Subsequently, the mice were trained on day 5 with methyl valerate paired with electric shocks and re-imaged on days 6 and 8. Several control mice (e.g. no odor, shock-only) were imaged too. Heart rate and respiration were monitored and recorded throughout all imaging sessions. Apart from the time when anesthetized for imaging purposes, the mice were not restrained and free to move in their cages.

Results:
We were able to show that fear conditioning is inducing significant plasticity in the rodent olfactory bulb by enhancing the odor map for methyl valerate. Using further control mice of another strain expressing a presynaptic indicator (SpH), we are going to show that this training-induced plasticity is specifically postsynaptic.