Laboratory for small animal imaging

For in-vivo small animal imaging we use the INVEON multimodal system (Siemens), which consists of a positron emission tomograph (PET) and a single photon emission computer tomograph (SPECT) combined with a computer tomograph (CT) (see Figure 1): the density of different receptors (A1 adenosinergic receptors, D2/3 dopaminergic receptors, metabotropic glutamatergic receptors) can be studied in the rodent brain with high spatial resolution and high sensitivity. For exact pharmacokinetic modelling, radioactive metabolites are determined in blood.

Figure 1: INVEON combined PET/SPECT/CT system.

Fig. 2: Spatial resolution of the PET system.

Fig. 3: Distribution of D2/3 dopaminergic receptors in horizontal brain slices of the rat. A high binding (red) is found in the caudate-putamen.

Fig. 4: Distribution of A1 adenosinergic receptors in horizontal brain slices of the rat. A high binding (red) is found in the caudate-putamen, thalamus and cerebellum.

Fig. 5: Distribution of glutamatergic receptors (metabotropic, type 5) in horizontal brain slices of the rat:

The receptor density was defined in-vivo by PET using [11C]ABP688 as radioligand (A and B). Afterwards the in-vivo results were verified by in-vitro autoradiography using [3H]ABP688 as radioligand (C and D). The high binding of the radioligand (red, A and C) is reduced by blocking the receptors with MPEP (B and C).

Within the scope of the project Sleepless, we evaluate quantitative PET imaging in awake animals by using radioactive marker based motion correction.