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Welcome to the Metabolic Neuroimaging group of the IDM at the University of Tuebingen

How does the fetal brain respond to light? Red light passes through tissue to reach the fetus, allowing us to record fetal neural responses to visual stimuli with fMEG.

As part of the Institute for Diabetes Research and Metabolic Diseases, or IDM (see main page at the Helmholtz Zentrum München here), we research the crosstalk between brain and peripheral organs, especially insulin signaling in the brain, from the fetus to the elderly. We use different brain imaging techniques (fMRI, fMEG and fNIRS) to study neurobiological mechanisms in obesity and diabetes as well as fetal development in context of the maternal metabolism. Cognitive functions are investigated using event related brain responses in the fetuses and food choice tasks in the adult.

We primarily study gestational diabetes using fetal magnetoencephalography (abbreviated fetal MEG or simply fMEG). MEG is a noninvasive technique for recording magnetic brain signals, most often using superconducting magnetometers or SQUIDs. Of over one hundred active MEG sites in the world, our laboratory is one of only two locations equipped with bespoke SQUID-MEG equipment for fetal brain recordings. We call this device the SQUID Array for Reproductive Assessment (SARA). The SARA device uses a concave array of SQUID sensors that compliments the maternal abdomen, allowing close proximity of the sensors to the fetus. Because magnetic fields are not distorted by biological tissue in the same manner as electric fields, MEG provides a solution for non-invasive recordings of fetal neural activity at high temporal resolution. As far as we know, fetal recordings are not currently possible using MEG’s sister technology, EEG, except during rare circumstances (mainly, during labor). EEG is not practical for fetal recordings due in part to the electrical resistance of the electrical resistance of the vernix caseosa, a waxy membrane that covers the fetal body.

Only two sites worldwide (shown in red), including our lab Tuebingen, are specialized for fetal MEG. Other locations have or once had general purpose machines for recording fetal biomagnetic signals (shown in magenta). — This map of MEG systems shows the rarity of sites equipped for infant — and especially fetal — recordings. Source: Frohlich et al. 2023 Neuroimage [https://doi.org/10.1016/j.neuroimage.2023.120057]

The SARA device can also record infant brain activity, and several of our studies have recorded neural signals from newborn infants placed in a cradle headfirst toward the sensor array. Infant-friendly headphones are used to deliver auditory stimuli. For fetal studies, auditory stimuli are delivered using an MEG-compatible sound balloon. Even in the womb, light from the outside world reaches the fetus. Because red wavelengths of light pass through biological tissue (try shining a flashlight behind your hand), we can record neural responses to visual stimuli using red LEDs and fiberoptic cables (see image at the top of page).

So, where on Earth does all this research happen? We are located in Tuebingen, a beautiful town of 90,000 people in the German state of Baden-Wuerttemberg. The laboratory sits atop the Klinikum Berg next to the University Hospital.