Super-resolution microscopy reveals functional organization of dopamine transporters into cholesterol and neuronal activity-dependent nanodomains

The dopamine transporter (DAT) has a crucial role in the regulation of neurotransmission. Here, the authors use super-resolution imaging to show that DAT clusters into cholesterol-dependent membrane regions that are reversibly regulated by ionotropic glutamate receptors activation

A novel dopamine transporter transgenic mouse line for identification and purification of midbrain dopaminergic neurons reveals midbrain heterogeneity

Midbrain dopaminergic (DAergic) neurons are heterogeneous and composed of functionally distinct cell populations projecting to the basal ganglia, prefrontal cortex and limbic system. Despite their functional significance, the midbrain population of DAergic neurons is sparse, constituting 20–30,000 neurons in mice, and development of novel tools to identify these cells is warranted. Here, we characterize a bacterial artificial chromosome (BAC) mouse line (Dat1-eGFP) from Gene Expression Nervous System Atlas that expresses enhanced green fluorescent protein (eGFP) under control of the dopamine transporter (DAT) promoter. Confocal microscopy analysis of brain sections showed strong eGFP reporter in midbrain regions and striatal terminals that co-localized with the DAergic markers DAT and tyrosine hydroxylase (TH). Thorough quantification of co-localisation of the eGFP reporter signal with DAT and TH in the ventral midbrain showed that a vast majority of eGFP-expressing neurons are DAergic. Importantly, expression profiles also revealed DAergic heterogeneity when comparing substantia nigra (SN) and ventral tegmental area (VTA). Dat1-eGFP mice showed neither change in synaptosomal dopamine uptake nor altered levels of DAT and TH in both striatum and midbrain. We found no behavioral difference between Dat1-eGFP and wildtype suggesting that the strain is not aberrant. Finally, cell populations highly enriched in DAergic neurons can be obtained from postnatal mice by fluorescence-activated cell sorting and the sorted neurons can be cultured in vitro. Our investigation demonstrates that eGFP expression in this mouse line is selective for DAergic neurons, suggesting that the Dat1-eGFP mouse strain constitutes a promising tool for delineating new aspects of dopamine biology