A study by Yu Kasugai et al. was published this month in the European Journal of Neuroscience. It is entitled, 'Quantitative localisation of synaptic andextrasynaptic GABAA receptor subunits onhippocampal pyramidal cells by freeze-fracturereplica immunolabelling' (Full text PDF). The cover features an electron micrograph taken by Peter Somogyi of GABAA receptor immunogold labelling (10 nm, yellow, false colour) on freeze fracture replica of the membrane of a pyramidal cell small oblique dendrite in the hippocamal stratum radiatum of the rat. The intramembrane particles representing the extracellular domain of transmembrane proteins appear as small protrusions on the cytoplasmic half of the plasma membrane. The patch of membrane that has a high concentration of intramembrane particles, and is also densely immunogold labelled for the beta-3 subunit, is the postsynaptic junctional area. Lower density of scattered gold particles label extrasynaptic receptors.