Friederike Kienzler  

Home Institution
Johann Wolfgang Goethe Universität, Frankfurt
Dr. Senckenbergsche Anatomie

Host Institution(s)
University of Arizona, Department of Pharmacology, Tucson
Mentor: Robert S. Sloviter, Ph.D.

E-Mail: f_kienzler@yahoo.de
Research Topic
see Abstract
Personal Reactions to the U.S. Experience
The decision to spend a year in the Wild West turned out to be a good experience. I ended up in Tucson, Arizona, a city with proximately 500,000 people, located in a valley close to beautiful mountain ranges. It seemed to me that it was urbanized only after the invention of air conditioning, cars, and highways. Since nothing but the desert keeps the city from expanding, the distances from one place to another are enormous. Therefore, the only possibility to get around is by car. Downtown, on the other hand, is rather small and it took me a while to find fun places to go out.
The area surrounding Tucson is beautiful! Mt. Lemmon to the north, Cochise Stronghold to the east, as well as the desert all around, are a rock climber’s paradise and a great place to shoot guns.
At the University of Arizona I worked in Professor Sloviter’s lab in the Department of Pharmacology. The head of the lab turned out to be a great scientist, teacher, supervisor, and one of the best pizza bakers I have ever met! Combined with his extraordinary good sense of humor, he created a great working atmosphere for everyone in the lab. He was very approachable, answered all sorts of questions and was always ready for an interesting discussion.
As long as you are motivated and enthusiastic about what you are doing, and willing to invest time into your research project, you will get great support.
Greatest Difficulties Encountered
Organizing the permission to do animal experiments was probably the most problematic and annoying experience I had. Not only did it include lots of paperwork, but classes and online tests as well. Therefore, it took forever until I actually got things done. But thanks to the great help and support from my fellow students, my frustration remained in a bearable range.
Most humorous incident
I experienced lots of hilarious moments during my stay. One day, for example, I went together with three fellow students to the Tucson Rodeo, one of the biggest rodeos in the USA. While sitting in-between all these cowboys, Ben Oblinsky, a technician, decided to put tremendously ugly, fake teeth into his mouth in order to ensure that our group would blend into the crowd better. Although he looked quite terrifying, nobody else seemed to take notice.
Helpful Hints for Future Students
- Since the public transportation is lacking and very poorly organized in Tucson, you should make sure that you: live close to the place you are working, live close to a bus stop, or have access to a car.
  • Don’t be afraid to ask questions.
  • Go climbing.
  • Wear sunscreen.

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Abstract on Research Topic
Characterizing an animal model of temporal lobe epilepsy with hippocampal sclerosis
Temporal lobe epilepsy is a long-known syndrome, but the mechanisms behind its pathology are not well understood. To study the mechanisms underlying the development of epilepsy, different animal models have been employed. Chemically-induced (pilocarpine and kainate) and electrical stimulation-induced seizures/epilepsy are the two most popular approaches to studying this disease. With electrical stimulation of the perforant pathway, the main input to the hippocampus, it is possible to produce a highly selective and reproducible pattern of seizure-induced hippocampal damage, largely restricted to the dentate gyrus, without the prolonged status epilepticus or widespread brain damage found in chemically-treated animals.

Adult C57Bl6 mice were anesthetized with urethane and stimulated for 2h, 4h, 8h, and 24h (continuous 2 Hz stimulation with 40ms paired-pulses; 10s trains of single stimuli at 20 Hz each minute). Stimulating electrode placement in the perforant pathway and record electrode location in the granule cell layer of the dentate gyrus were performed stereotaxically. Paired-pulse stimulation evoked field potentials and population spikes of granule cells in the ipsi- as well as the contra-lateral dentate gyrus. Electrical seizure-like activity was recorded during the stimulation. Animals were perfused from four days to four months post-stimulation for a time course analysis. Cellular changes in the hippocampus were studied through the use of: Nissl (cresyl violet) and NeuN immunostaining, both markers for surviving neurons; parvalbumin, somatostatin, NPY, and calretinin to determine the types of surviving neurons. Four days after stimulation, more than 80% of neurons in the hilus the dentate gyrus were lost. In addition, the number of parvalbumin-immunoreactive neurons in the dentate gyrus was significantly decreased, suggesting this population is especially vulnerable to this electrical stimulation paradigm. Video monitoring post-stimulation showed that mice stimulated for 24h became epileptic, i.e. developed spontaneous behavioral seizures.

Using this model of human temporal lobe epilepsy will make possible the use of transgenic mice to study the molecular and cellular mechanisms underlying activity-dependent cellular changes in the dentate gyrus.