E MOS. By contrast, our mechanistic understanding of AOS function is still fragmentary (Box 1). In this critique post, we present an update on present information with the rodent AOS and discuss some of the big challenges lying ahead. The primary emphasis of this overview concerns the nature of the computations performed by the initial stages on the AOS, namely sensory neurons on the VNO and circuits in the accessory olfactory bulb (AOB).The vomeronasal organThe rodent VNO can be a paired cylindrical structure in the base of your anterior nasal septum (Meredith 1991; Halpern and MartinezMarcos 2003). Just above the palate, the blind-ended tubular organ, enclosed within a cartilaginous capsule, opens anteriorly to the nasal cavity by way of the vomeronasal duct (Figure 1). Regardless of whether the organ is functional at birth or gains functionality in the course of a later developmental stage continues to be subject to debate (Box 2). In the adult mouse, every single VNO harbors approximately 100 000 to 200 000 vomeronasal sensory neurons (VSNs; Wilson and Raisman 1980), which obtain both structural and metabolic assistance from a band of sustentacular cells within the most superficial layer of a crescent-shaped pseudostratified neuroepithelium. VSNs show a characteristic morphology: as bipolar neurons, they extend a single unbranched dendrite from the apical pole of a compact elliptical soma ( five in diameter). The apical dendrites terminate inside a paddle-shaped swelling that harbors several microvilli at its tip (knob). These microvilli are immersed within a viscous mucus that’s secreted by lateral glands and fills the whole VNO lumen. Hence, the microvillar arrangement supplies a massive extension on the neuroepithelium’s interface with the external environment. From their basal pole, VSNs project a lengthy unmyelinated axon. In the basal lamina, numerous these VSN axons fasciculate into vomeronasal nerve bundles that run in dorsal path under the septal respiratory and olfactory epithelia. With each other with olfactory nerve fibers, VSN axon bundles enter the brain by way of little fenestrations inside the ethmoid bone’s cribriform plate. The vomeronasal nerve then projects along the medial olfactory bulbs and targets the glomerular layer from the AOB (Meredith 1991; Belluscio et al. 1999; Rodriguez et al. 1999). On its lateral side, the VNO is composed of very vascularized cavernous tissue. A prominent huge blood vessel supplies a characteristic anatomical landmark (Figure 1). In his original publication, Jacobson already noted the wealthy innervation on the organ’s lateral elements (Jacobson et al. 1998). The majority of these sympathetic fibers originate in the superior cervical ganglion, enter the posterior VNO along the nasopalatine nerve, and innervate the large lateral vessel (Meredith and O’Connell, 1979; Eccles, 1982; Ben-Shaul et al., 2010). Even though in many species vomeronasal stimulus uptake isChemical Senses, 2018, Vol. 43, No.Box 1 The AOS: an emerging 66-81-9 In Vivo multi-scale model to study how sensory stimuli drive behavior A essential target in neuroscience should be to realize how sensory stimuli are detected and processed to in the end drive behavior. Provided the inherent complexity of your activity, attempts to achieve a holistic (i.e., multi-scale) analytical perspective on sensory coding have frequently resorted to reductionist approaches in Benzamidine In stock invertebrate model organisms such as nematodes or fruit flies. In such models, the “from-gene-tobehavior” approach has verified really effective and, accordingly, has led to quite a few breakth.