This volume contains the proceedings of the Ninth Meeting of the "International Study Group for Tryptophan Research" (lSTRY), held at the University of Hamburg, Germany, from October 10 to 14, 1998. At this meeting the recent developments in the field of tryptophan research were presented by leading researchers from all over the world in 81 oral and 48 poster contri- butions. Research on tryptophan and its derivatives provides an inexhaustible subject. At the conference we tried to compose a multifacetted picture of the recent investiga- tions through contributions from the major disciplines...

English summary: Inner images are all those pictures that we carry within us and influence our feelings and actions. Such images are ideas and visions of who we are, what we find achievable and what we would like to achieve. They are stored patterns in our brain that we use to find our way in life. We need these images to plan actions, to take on challenges and to react on threats. Due to these pictures we find things beautiful and attractive or ugly and repulsive.Inner images are therefore decisive for how and what we use our brain for. Where do these inner images come from? How are they...

English summary: The human brain is much more flexible than hitherto thought. The way brain cells are used strongly influences how neurons connect with each other. Since little boys, teenagers and later adult representatives of the male sex take an interest in things so different from their female counterparts, it is obvious that male brains must develop differently. If males would use their brains accordingly, they could become more powerful. German description: Wie wird ein Mann ein Mann? Oder etwas praziser: Wie wird aus dem, was ein Mann werden konnte, schliealich das, wofur sich der...

In der modernen Hirnforschung wurden bahnbrechende Entdeckungen gemacht. Die sogenannte Plastizitat des menschlichen Gehirns bedeutet, dass es lebenslang veranderbar, ausbaubar, anpassungsfahig ist. Sogar die Masse der Gehirnzellen ist, entgegengesetzt der fruheren Auffassung der Wissenschaftler, nicht endgultig festgelegt, sondern kann im Verlauf des Lebens noch zunehmen. Nach den neuesten Erkenntnissen der Hirnforscher hat die Art und Weise der Nutzung des Gehirns einen entscheidenden Einfluss darauf, welche neuronalen Verschaltungen angelegt und stabilisiert oder auch destabilisiert...

English summary: We fear nothing more than our very own angst. Our angst however in all its shades is what makes us develop mentally and emotionally. Only angst provokes a stress-reaction process which establishes the precondition for arranging one's life mentally, emotionally and bodily. Gerald Huther presents the latest scientific findings of stress reactions in the biological functions of the brain and gives surprising insights of basic emotional patterns like trust, belief, love, dependence, hate and aggression. Neuronal connection patterns which we learn in our early childhood...

The picture on the following page is being reproduced here, at the request of the partici pants in the Advanced Research Workshop "Amino Acid Availability and Brain Function in Health and Disease." I displayed this limewood carving, entitled "Neurochemistry," during my closing remarks to this extraordinarily stimulating and productive workshop so ably organized by my collaborator Dr. Gerald Huether. We scientists need two sturdy legs to carry us through all the twists and turns of our academic careers. We should also have, as it were, a reserve leg handy, to help us stay upright when this...

This volume contains the proceedings of the Ninth Meeting of the "International Study Group for Tryptophan Research" (lSTRY), held at the University of Hamburg, Germany, from October 10 to 14, 1998. At this meeting the recent developments in the field of tryptophan research were presented by leading researchers from all over the world in 81 oral and 48 poster contri- butions. Research on tryptophan and its derivatives provides an inexhaustible subject. At the conference we tried to compose a multifacetted picture of the recent investiga- tions through contributions from the major disciplines...