Research in our laboratory has focused on mechanisms that determine activity-dependent modifications of the function and structure of neurons. These modifications, including long-term potentiation and long-term depression, occur during the development of the nervous system, but represent also an ongoing feature of neurons in adults. We study different types of neurons in the cortex, cerebellum and hippocampus, and use a variety of techniques, including patch-clamp recordings from neurons in brain slices and high-resolution imaging. In the cerebellum, we determined previously elementary properties of GABAergic and glutamatergic synaptic transmission, including the mechanisms of IP 3-evoked calcium release signaling in spiny dendrites of Purkinje cells through the activation of metabotropic glutamate receptors. More recently we investigated the contribution of various molecular determinants (e.g. G-proteins, calbindin, ryanodine receptors) for cerebellar calcium signaling. In an effort to understand the major modulators of synaptic plasticity in the hippocampus and cortex, we started a few years ago to study the mechanisms of neurotrophins, especially those of brain-derived neurotrophic factor (BDNF) and the corresponding receptor tyrosine kinase TrkB. Another major focus of the laboratory is the investigation of the mechanisms of synaptic wiring in the immature cortex and hippocampus. After observing the activity-dependent of conversion of silent glutamatergic synapses into conducting ones in the developing hippocampus, we started to investigate synaptic signaling and plasticity in immature neuronal networks.