Single-cell proteomics: A treasure trove in neurobiology.

Single-cell analysis came to change the way we look at cell populations. RNA sequencing of single cells allowed us to appreciate the diversity of cell types in the human brain in an unprecedented manner and its power to reveal cell-type specific changes in cell populations has just begun to be explored. In this context, looking at the proteome of single cells promises to bring functional information and contribute to completing the picture. The potential of single cell proteome, in developing a better understanding of the intricate connections between the very diverse cell populations in the brain, is huge. Whereas early approaches to address single-cell proteome have identified hundreds of proteins, today, techniques combining isobaric labelling and LC-MS can lead to the identification of thousands of proteins. In this review, we describe methods which have been used to identify and quantify proteins from single cells and propose that the application of isobaric labeling and label-free quantitative proteomics approach for single-cell analysis is ready to provide useful information for the neurobiology field.