Glycolipid-enriched caveolae and caveolae-like domains in the nervous system

Recent years have been characterized by a booming interest in research on caveolae and caveolae-like membrane domains. The interest in this subject grew further, when their involvement in fundamental membrane-associated events, such as signal transmission and lipid/protein sorting, was postulated. Substantial progress has been reached in understanding the biological role of membrane domains in eukaryotic cells. The neuron, however, which perhaps represents one of the greatest challenges to research on membrane traffic and function, has only been partially investigated. The purpose of the present review is to survey this issue in the nervous system. We confine ourselves to the presence of membrane domains in the nervous system and discuss this in the context of three facts: first, glycolipids are peculiarly enriched in both caveolae and caveolae-like domains and are particularly abundant in the nervous system; second, the neuron is characterized by a basic dual polarity, similar in this respect to other polarized cells, where the role of glycolipid-enriched domains for lipid/protein sorting has been better ascertained; and third, neurons evolved from, and are related to, simpler eukaryotic cells, allowing us to find analogies with more investigated nonneuronal cells.