Organisation of the tardigrade nervous system. Diagrams in the centre illustrate specimens of the tardigrade Macrobiotus cf. harmsworthi in ventral and lateral views (anterior is up). Nerve tracts are indicated in black. Circular insets show details (confocal micrographs) of the nervous system based on anti-tyrosinated and anti-acetylated α-tubulin immunolabelling. Abbreviations: al, anterior leg nerve; as, anterolateral sensory field; cl, cloacal nerves; cn, connective; dn, dorsolateral nerve tract; ip, interpedal commissure; lg, leg ganglion; ne, neurites supplying the peribuccal lamellae; nr, nerve ring innervating the peribuccal lamellae; pg, peripheral ganglion; pl, posterior leg nerve; pn, peripheral nerve; ps, posterolateral sensory field. Scale bars: 5 μm.