Lateral antennular neuropil

Fig. 7.2 Schematic representations of chemosensory pathways in the brain, (a) Lateral antennular neuropil (LAN) pathway. dCRNs and MRNs from sensilla on the lateral (LF) and medial (MF) antennular flagellum project somatotopically into both lobes of the LAN and couple directly to antennular motoneurons (MN), (b) Olfactory pathway. ORNs project nontopographically into the olfactory lobe (OL) which is organized into glomeruli. Information is processed by various types of multiglomerular local intemeurons (LN) and output is provided by multiglomerular projections neurons (PN) ascending to the lateral protocerebrum in the eyestalk ganglia...

Axons from chemo- and mechanosensory sensilla on the antennular flagella course within branches of the antennular nerve to three major target areas in the deutocer-ebrum The olfactory lobes (OL), the lateral antennular neuropil (LAN), and the median antennular neuropil (MAN). Backfilling techniques in spiny lobsters have established that ORNs connect with synaptic targets exclusively within the OL, while dCRN and MRN axons target the LAN and MAN (Schmidt et al. 1992 ... 

Schmidt M, Ache BW (1996a) Processing of antennular input in the brain of the spiny lobster, Panulirus argus. I. Non-olfactory chemosensory and mechanosensory pathway of the lateral and median antennular neuropils. J Comp Physiol A 178 579-604... 

Schmidt M, Van Ekeris L, Ache BW (1992) Antennular projections to the midbrain of the spiny lobster. I. Sensory innervation of the lateral and medial antennular neuropils. J Comp Neurol 318 277-290... 

Receptors for semiochemicals of lobsters and many other decapod crustaceans are typically restricted to a very limited set of sensors. These are olfactory sensory neurons contained in specialized setae called aesthetascs, localized in the lateral flagellum of the first antenna or antennule (Fig. 12.2). Ablation experiments show the necessity of aesthetascs for the response of lobsters to different types of semiochemicals (Johnson and Atema 2005 Homer et al. 2008 Shabani et al. 2008). The chemosensory neurons innervating the aesthetascs project their axons exclusively to the olfactory lobes, and thus are considered olfactory, while the other setae contain both chemo- and mechanoreceptors that project to the lateral and medial antennular neuropils (Schmidt and Ache 1996a, 1996b) (Schmidt and Mellon, Chap. 7). Many studies showed that receptor sites for semiochemicals are located in the first antenna without showing them to be in aesthetascs (e.g., Raethke et al. 2004 Skog 2009). Detectors of semiochemicals of crayfish have been... 

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