Implications from Microcircuits of a Moth’s Antennal Lobe for Olfactory Information Processing

2017 ◽  
pp. 333-344
Author(s):  
Hong Lei ◽  
Lynne A. Oland ◽  
Jeffery A. Riffell ◽  
Aaron Beyerlein ◽  
John G. Hildebrand
Keyword(s):  
Information Processing ◽  
Antennal Lobe ◽  
Neural Circuits ◽  
Functional Organization ◽  
Physiological Responses ◽  
Projection Neurons ◽  
Natural Behavior ◽  
Odor Cues ◽  
Ongoing Work ◽  
Output Neurons

Olfactory circuits of all animals face a common challenge of extracting meaningful odor cues from background odors. This chapter summarizes what the authors have learned from their ongoing work toward the goal of understanding how the neural circuits in a moth’s antennal lobe (AL) determine diverse physiological responses that ultimately mediate the animal’s natural behavior. The text describes the different types of cellular elements that participate in the glomerular circuitry, focuses on the functional organization of these elements, and attempts to explain observed physiological responses in the context of behavior using the understood operating principles of the AL circuits. For convenience, the connections from the perspective of the main output neurons of the circuitry, uniglomerular projection neurons (uPNs), are described.

scholarly journals Semi-intact ex vivo approach to investigate spinal somatosensory circuits

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Junichi Hachisuka ◽  
Kyle M Baumbauer ◽  
Yu Omori ◽  
Lindsey M Snyder ◽  
H Richard Koerber ◽  
...  
Keyword(s):  
Neural Circuits ◽  
Ex Vivo ◽  
Projection Neurons ◽  
New Approach ◽  
Spinal Interneurons ◽  
Somatosensory Input ◽  
Health And Disease ◽  
Output Neurons ◽  
Temporal And Spatial ◽  
Ex Vivo Approach

The somatosensory input that gives rise to the perceptions of pain, itch, cold and heat are initially integrated in the superficial dorsal horn of the spinal cord. Here, we describe a new approach to investigate these neural circuits in mouse. This semi-intact somatosensory preparation enables recording from spinal output neurons, while precisely controlling somatosensory input, and simultaneously manipulating specific populations of spinal interneurons. Our findings suggest that spinal interneurons show distinct temporal and spatial tuning properties. We also show that modality selectivity — mechanical, heat and cold — can be assessed in both retrogradely labeled spinoparabrachial projection neurons and genetically labeled spinal interneurons. Finally, we demonstrate that interneuron connectivity can be determined via optogenetic activation of specific interneuron subtypes. This new approach may facilitate key conceptual advances in our understanding of the spinal somatosensory circuits in health and disease.

The Functional Logic of Odor Information Processing in the Drosophila Antennal Lobe

2021 ◽  
Author(s):  
Aurel A Lazar ◽  
Tingkai Liu ◽  
Chung-Heng Yeh
Keyword(s):  
Information Processing ◽  
Steady State ◽  
Antennal Lobe ◽  
Stable Steady State ◽  
Projection Neurons ◽  
Olfactory Pathway ◽  
State Behavior ◽  
Key Characteristics ◽  
Functional Logic ◽  
Event Based

In the early olfactory pathway of Drosophila, Olfactory Sensory Neurons (OSNs) multiplicatively encode the odorant identity and the concentration profile. Projection Neurons (PNs) responses in the Antennal Lobe (AL), in turn, exhibit strong transients at odorant onset/offset and stable steady-state behavior. What is the functional logic the of diverse set of Local Neurons (LNs) in the AL Addressing this question may shed light on the key characteristics of odor information processing in the AL, and odorant recognition and olfactory associative learning in the downstream neuropils of the early olfactory system. To address the computation performed by each LN type, we exhaustively evaluated all circuit configurations of the Antennal Lobe. We found that, across model parameterizations, presynaptic inhibition of the OSN-to-PN synapse is essential for odorant identity recovery in steady-state, while postsynaptic excitation and inhibition facilitate on-/off-set event detection. The onset and offset events indicate changing odorant identities, and together with the identity recovery in steady-state, suggest that the AL is an event-based odorant identity recovery processor.

scholarly journals Coding of odour and space in the hemimetabolous insect Periplaneta americana

2019 ◽  
Author(s):  
Marco Paoli ◽  
Hiroshi Nishino ◽  
Einat Couzin-Fuchs ◽  
C. Giovanni Galizia
Keyword(s):  
Antennal Lobe ◽  
Periplaneta Americana ◽  
American Cockroach ◽  
Projection Neurons ◽  
Olfactory Coding ◽  
Selective Labelling ◽  
Hemimetabolous Insect ◽  
Summary Statement ◽  
Output Neurons ◽  
General Architecture

AbstractThe general architecture of the olfactory system is highly conserved from insects to humans, but neuroanatomical and physiological differences can be observed across species. The American cockroach, inhabiting dark shelters with a rather stable olfactory landscape, is equipped with long antennae used for sampling the surrounding air-space for orientation and navigation. The antennae’s exceptional length provides a wide spatial working range for odour detection; however, it is still largely unknown whether and how this is also used for mapping the structure of the olfactory environment. By selective labelling antennal lobe projection neurons with a calcium sensitive dye, we investigated the logic of olfactory coding in this hemimetabolous insect. We show that odour responses are stimulus-specific and concentration-dependent, and that structurally related odorants evoke physiologically similar responses. By using spatially confined stimuli, we show that proximal stimulations induce stronger and faster responses than distal ones. Spatially confined stimuli of the female pheromone periplanone-B activate sub-region of the male macroglomerulus. Thus, we report that the combinatorial logic of odour coding deduced from holometabolous insects applies also to this hemimetabolous species. Furthermore, a fast decrease in sensitivity along the antenna, not supported by a proportionate decrease in sensillar density, suggests a neural architecture that strongly emphasizes neuronal inputs from the proximal portion of the antenna.Summary statementBy selective labelling the cockroach’s antennal lobe output neurons, we investigated the logic of olfactory coding in a hemimetabolous insect, showing that odour responses are stimulus-specific, concentration-dependent, and preserve information on the spatial structure of the stimulus.

Morphology and physiology of antennal lobe projection neurons in the hawkmoth Agrius convolvuli

2017 ◽  
Vol 98 ◽  
pp. 214-222 ◽  
Author(s):  
Takuya Nirazawa ◽  
Takeshi Fujii ◽  
Yoichi Seki ◽  
Shigehiro Namiki ◽  
Tomoki Kazawa ◽  
...  
Keyword(s):  
Antennal Lobe ◽  
Projection Neurons

Temporal summation properties of the olfactory projection neurons in the moth antennal lobe revealed by optogenetic stimulation

2011 ◽  
Vol 71 ◽  
pp. e79
Author(s):  
Masashi Tabuchi ◽  
Takeshi Sakurai ◽  
Hidefumi Mitsuno ◽  
Shigehiro Namiki ◽  
Ryo Minegishi ◽  
...  
Keyword(s):  
Antennal Lobe ◽  
Temporal Summation ◽  
Projection Neurons ◽  
Optogenetic Stimulation

scholarly journals Alarm calls elicit predator-specific physiological responses

2010 ◽  
Vol 6 (5) ◽  
pp. 623-625 ◽  
Author(s):  
Jill M. Mateo
Keyword(s):  
Information Processing ◽  
Physiological Responses ◽  
Ground Squirrels ◽  
Alarm Calls ◽  
Cortisol Response ◽  
Behavioural Responses ◽  
Cortisol Responses ◽  
Cortisol Increase ◽  
Physiological Reactions ◽  
Very High

Glucocorticoids regulate glucose concentrations and responses to unpredictable events, while also modulating cognition. Juvenile Belding's ground squirrels ( Urocitellus beldingi ) learn to respond to whistle and trill alarm calls, warning of aerial and terrestrial predators, respectively, shortly after emerging from natal burrows at one month of age. Alarm calls can cause physiological reactions and arousal, and this arousal, coupled with watching adult responses, might help juveniles learn associations between calls and behavioural responses. I studied whether young show differential cortisol responses to alarm and non-alarm calls, using playbacks of U. beldingi whistles, trills, squeals (a conspecific control vocalization) and silent controls. Trills elicited very high cortisol responses, and, using an individual's response to the silent control as baseline, only their response to a trill was significantly higher than baseline. This cortisol increase would provide glucose for extended vigilance and escape efforts, which is appropriate for evading terrestrial predators which hunt for long periods. Although whistles do not elicit a cortisol response, previous research has shown that they do result in bradycardia, which enhances attention and information processing. This is a novel demonstration of two physiological responses to two alarm calls, each appropriate to the threats represented by the calls.

scholarly journals Interneuron Diversity: Toward a Better Understanding of Interneuron Development In the Olfactory System

2019 ◽  
Vol 13 ◽  
pp. 117906951982605
Author(s):  
Chi-Jen Yang ◽  
Kuo-Ting Tsai ◽  
Nan-Fu Liou ◽  
Ya-Hui Chou
Keyword(s):  
Olfactory System ◽  
Neural Circuits ◽  
Projection Neurons ◽  
Intrinsic Properties ◽  
Recent Advances ◽  
Local Interneurons ◽  
Olfactory Interneurons ◽  
High Diversity ◽  
Interneuron Development

The Drosophila olfactory system is an attractive model for exploring the wiring logic of complex neural circuits. Remarkably, olfactory local interneurons exhibit high diversity and variability in their morphologies and intrinsic properties. Although olfactory sensory and projection neurons have been extensively studied of development and wiring; the development, mechanisms for establishing diversity, and integration of olfactory local interneurons into the developing circuit remain largely undescribed. In this review, we discuss some challenges and recent advances in the study of Drosophila olfactory interneurons.

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