Saggau Lab

Baylor College of Medicine

CA1 pyramidal neurons from rat hippocampus. Images acquired by Brad Losavio.

The research interests in our lab are twofold: to understand the biophysics of central mammalian neurons that control both the communication between cells and their individual computational properties, and to develop advanced optical imaging tools for studying living brain tissue that help us to achieve this goal.

Our lab mainly focuses on synaptic transmission and dendritic integration. Presynaptically, we have described modulation of presynaptic voltage-dependent calcium channels (VDCCs), where the transient influx of Ca2+ determines the timing and amount of neurotransmitter release. We have also studied postsynaptic VDCCs and their modulation in dendritic spines, where transient Ca2+ elevations can trigger long-term changes in synaptic plasticity. Further, we are probing dendritic integration by investigating spatio-temporal summation of individual synaptic inputs.

Techniques used in our lab to address these and other challenging issues include high-speed micro-photometry, as well as combined whole-cell patch clamp and confocal/multiphoton microscopy. We also construct realistic computational models based on morphological reconstructions of living neurons.

We are actively involved in developing advanced optical techniques to overcome the technical difficulties inherent in stimulating and recording in the very fine structures of neuronal dendrites. We developed a novel high-speed laser-scanning microscope that allows for concurrent multi-site optical stimulation by local release of neurotransmitter and optical recording of membrane potential and intracellular ions. We are also developing next generation optical stimulation and recording systems with improved spatio-temporal resolution based on multiphoton excitation via acousto-optic control of near infrared ultra-fast laser pulses. These advanced techniques will enable structural and functional optical imaging in intact neural tissue and provide new insights into normal and pathological brain function.