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Implementation of olfactory bulb glomerular-layer computations in a digital neurosynaptic core.

Imam N, Cleland TA, Manohar R, Merolla PA, Arthur JV, Akopyan F, Modha DS - Front Neurosci (2012)

Bottom Line: Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits.The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons.Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems.

View Article: PubMed Central - PubMed

Affiliation: Computer Systems Lab, Department of Electrical and Computer Engineering, Cornell University Ithaca, NY, USA.

ABSTRACT
We present a biomimetic system that captures essential functional properties of the glomerular layer of the mammalian olfactory bulb, specifically including its capacity to decorrelate similar odor representations without foreknowledge of the statistical distributions of analyte features. Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits. The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons. This configuration generates functional transformations comparable to those observed in the glomerular layer of the mammalian olfactory bulb. Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems.

No MeSH data available.


Related in: MedlinePlus

Circuit diagram of the mammalian olfactory bulb glomerular layer (two columns depicted). Olfactory sensory neurons (OSNs), housed in the olfactory epithelium of the nasal cavity (OE), project their axons into olfactory bulb. OSN axons expressing the same odorant receptor type converge to form glomeruli (shaded ovals) on the surface of the olfactory bulb, within which they interact with multiple classes of olfactory bulb principal neurons and interneurons. Principal neurons include mitral cells (Mi) and middle/deep tufted cells (often considered together with mitral cells; not shown). Glomerular interneurons include olfactory nerve-driven periglomerular cells (PGo), external tufted (ET) cell-driven periglomerular cells (PGe), and multiple subtypes of ET cells; both types of PG cells inhibit mitral cells. Superficial short-axon cells (sSA) are not associated with specific glomeruli but project broadly and laterally within the deep glomerular layer, interacting with glomerular interneurons. GL, glomerular layer; MCL, mitral cell layer. Deeper layers of olfactory bulb (Cleland, 2010) are not depicted.
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Figure 1: Circuit diagram of the mammalian olfactory bulb glomerular layer (two columns depicted). Olfactory sensory neurons (OSNs), housed in the olfactory epithelium of the nasal cavity (OE), project their axons into olfactory bulb. OSN axons expressing the same odorant receptor type converge to form glomeruli (shaded ovals) on the surface of the olfactory bulb, within which they interact with multiple classes of olfactory bulb principal neurons and interneurons. Principal neurons include mitral cells (Mi) and middle/deep tufted cells (often considered together with mitral cells; not shown). Glomerular interneurons include olfactory nerve-driven periglomerular cells (PGo), external tufted (ET) cell-driven periglomerular cells (PGe), and multiple subtypes of ET cells; both types of PG cells inhibit mitral cells. Superficial short-axon cells (sSA) are not associated with specific glomeruli but project broadly and laterally within the deep glomerular layer, interacting with glomerular interneurons. GL, glomerular layer; MCL, mitral cell layer. Deeper layers of olfactory bulb (Cleland, 2010) are not depicted.

Mentions: In biological olfaction, inhaled odorants associate with olfactory receptors (ORs) expressed on the apical cilia of olfactory sensory neurons (OSNs) that line the nasal cavity (a circuit diagram depicting OSN projections and the olfactory bulb glomerular layer is depicted in Figure 1). ORs are typical G-protein coupled receptors, but are hugely diverse in their ligand selectivities; overall, roughly 350 different functional ORs are expressed in humans, and over 1000 in mice and rats. The range of odor ligand features that bind to and activate a given OR constitute its chemoreceptive field (aka molecular receptive range). The chemoreceptive fields of different ORs overlap substantially, such that odors – even those comprising only one type of molecule – will activate a substantial fraction of the available ORs to a greater or lesser degree. It is the combinatorial pattern across the set of receptors that forms the basis for odor perception and identification, and, importantly, the basis for odor similarity. Perceptually similar odors activate a correspondingly greater number of common ORs, and evoke more highly overlapping primary odor representations. However, perceptual similarity is also substantially regulated by centrifugal neuromodulatory inputs and by intrinsic learning (Cleland et al., 2009; Mandairon and Linster, 2009), and mediated by the intrinsic circuitry of olfactory bulb.


Implementation of olfactory bulb glomerular-layer computations in a digital neurosynaptic core.

Imam N, Cleland TA, Manohar R, Merolla PA, Arthur JV, Akopyan F, Modha DS - Front Neurosci (2012)

Circuit diagram of the mammalian olfactory bulb glomerular layer (two columns depicted). Olfactory sensory neurons (OSNs), housed in the olfactory epithelium of the nasal cavity (OE), project their axons into olfactory bulb. OSN axons expressing the same odorant receptor type converge to form glomeruli (shaded ovals) on the surface of the olfactory bulb, within which they interact with multiple classes of olfactory bulb principal neurons and interneurons. Principal neurons include mitral cells (Mi) and middle/deep tufted cells (often considered together with mitral cells; not shown). Glomerular interneurons include olfactory nerve-driven periglomerular cells (PGo), external tufted (ET) cell-driven periglomerular cells (PGe), and multiple subtypes of ET cells; both types of PG cells inhibit mitral cells. Superficial short-axon cells (sSA) are not associated with specific glomeruli but project broadly and laterally within the deep glomerular layer, interacting with glomerular interneurons. GL, glomerular layer; MCL, mitral cell layer. Deeper layers of olfactory bulb (Cleland, 2010) are not depicted.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368244&req=5

Figure 1: Circuit diagram of the mammalian olfactory bulb glomerular layer (two columns depicted). Olfactory sensory neurons (OSNs), housed in the olfactory epithelium of the nasal cavity (OE), project their axons into olfactory bulb. OSN axons expressing the same odorant receptor type converge to form glomeruli (shaded ovals) on the surface of the olfactory bulb, within which they interact with multiple classes of olfactory bulb principal neurons and interneurons. Principal neurons include mitral cells (Mi) and middle/deep tufted cells (often considered together with mitral cells; not shown). Glomerular interneurons include olfactory nerve-driven periglomerular cells (PGo), external tufted (ET) cell-driven periglomerular cells (PGe), and multiple subtypes of ET cells; both types of PG cells inhibit mitral cells. Superficial short-axon cells (sSA) are not associated with specific glomeruli but project broadly and laterally within the deep glomerular layer, interacting with glomerular interneurons. GL, glomerular layer; MCL, mitral cell layer. Deeper layers of olfactory bulb (Cleland, 2010) are not depicted.
Mentions: In biological olfaction, inhaled odorants associate with olfactory receptors (ORs) expressed on the apical cilia of olfactory sensory neurons (OSNs) that line the nasal cavity (a circuit diagram depicting OSN projections and the olfactory bulb glomerular layer is depicted in Figure 1). ORs are typical G-protein coupled receptors, but are hugely diverse in their ligand selectivities; overall, roughly 350 different functional ORs are expressed in humans, and over 1000 in mice and rats. The range of odor ligand features that bind to and activate a given OR constitute its chemoreceptive field (aka molecular receptive range). The chemoreceptive fields of different ORs overlap substantially, such that odors – even those comprising only one type of molecule – will activate a substantial fraction of the available ORs to a greater or lesser degree. It is the combinatorial pattern across the set of receptors that forms the basis for odor perception and identification, and, importantly, the basis for odor similarity. Perceptually similar odors activate a correspondingly greater number of common ORs, and evoke more highly overlapping primary odor representations. However, perceptual similarity is also substantially regulated by centrifugal neuromodulatory inputs and by intrinsic learning (Cleland et al., 2009; Mandairon and Linster, 2009), and mediated by the intrinsic circuitry of olfactory bulb.

Bottom Line: Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits.The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons.Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems.

View Article: PubMed Central - PubMed

Affiliation: Computer Systems Lab, Department of Electrical and Computer Engineering, Cornell University Ithaca, NY, USA.

ABSTRACT
We present a biomimetic system that captures essential functional properties of the glomerular layer of the mammalian olfactory bulb, specifically including its capacity to decorrelate similar odor representations without foreknowledge of the statistical distributions of analyte features. Our system is based on a digital neuromorphic chip consisting of 256 leaky-integrate-and-fire neurons, 1024 × 256 crossbar synapses, and address-event representation communication circuits. The neural circuits configured in the chip reflect established connections among mitral cells, periglomerular cells, external tufted cells, and superficial short-axon cells within the olfactory bulb, and accept input from convergent sets of sensors configured as olfactory sensory neurons. This configuration generates functional transformations comparable to those observed in the glomerular layer of the mammalian olfactory bulb. Our circuits, consuming only 45 pJ of active power per spike with a power supply of 0.85 V, can be used as the first stage of processing in low-power artificial chemical sensing devices inspired by natural olfactory systems.

No MeSH data available.


Related in: MedlinePlus