scholarly journals Odor identity coding by distributed ensembles of neurons in the mouse olfactory cortex

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Benjamin Roland ◽  
Thomas Deneux ◽  
Kevin M Franks ◽  
Brice Bathellier ◽  
Alexander Fleischmann
Keyword(s):  
Olfactory Bulb ◽  
Calcium Imaging ◽  
Spatial Organization ◽  
Piriform Cortex ◽  
Olfactory Cortex ◽  
Olfactory Perception ◽  
Response Patterns ◽  
Odor Concentration ◽  
Wide Range ◽  
Population Representation

Olfactory perception and behaviors critically depend on the ability to identify an odor across a wide range of concentrations. Here, we use calcium imaging to determine how odor identity is encoded in olfactory cortex. We find that, despite considerable trial-to-trial variability, odor identity can accurately be decoded from ensembles of co-active neurons that are distributed across piriform cortex without any apparent spatial organization. However, piriform response patterns change substantially over a 100-fold change in odor concentration, apparently degrading the population representation of odor identity. We show that this problem can be resolved by decoding odor identity from a subpopulation of concentration-invariant piriform neurons. These concentration-invariant neurons are overrepresented in piriform cortex but not in olfactory bulb mitral and tufted cells. We therefore propose that distinct perceptual features of odors are encoded in independent subnetworks of neurons in the olfactory cortex.

Cortical Processing of Odorants

2017 ◽  
Author(s):  
Yaniv Cohen ◽  
Emmanuelle Courtiol ◽  
Regina M. Sullivan ◽  
Donald A. Wilson
Keyword(s):  
Olfactory Bulb ◽  
Sensory Neurons ◽  
Perceptual Experience ◽  
Spatial Organization ◽  
Piriform Cortex ◽  
Olfactory Sensory Neurons ◽  
Anterior Olfactory Nucleus ◽  
Molecular Features ◽  
Cortical Nucleus ◽  
Local Circuitry

Odorants, inhaled through the nose or exhaled from the mouth through the nose, bind to receptors on olfactory sensory neurons. Olfactory sensory neurons project in a highly stereotyped fashion into the forebrain to a structure called the olfactory bulb, where odorant-specific spatial patterns of neural activity are evoked. These patterns appear to reflect the molecular features of the inhaled stimulus. The olfactory bulb, in turn, projects to the olfactory cortex, which is composed of multiple sub-units including the anterior olfactory nucleus, the olfactory tubercle, the cortical nucleus of the amygdala, the anterior and posterior piriform cortex, and the lateral entorhinal cortex. Due to differences in olfactory bulb inputs, local circuitry and other factors, each of these cortical sub-regions appears to contribute to different aspects of the overall odor percept. For example, there appears to be some spatial organization of olfactory bulb inputs to the cortical nucleus of the amygdala, and this region may be involved in the expression of innate odor hedonic preferences. In contrast, the olfactory bulb projection to the piriform cortex is highly distributed and not spatially organized, allowing the piriform to function as a combinatorial, associative array, producing the emergence of experience-dependent odor-objects (e.g., strawberry) from the molecular features extracted in the periphery. Thus, the full perceptual experience of an odor requires involvement of a large, highly dynamic cortical network.

scholarly journals Non-invasive recording from the human olfactory bulb

2019 ◽  
Author(s):  
Behzad Iravani ◽  
Artin Arshamian ◽  
Kathrin Ohla ◽  
Donald A. Wilson ◽  
Johan N. Lundström
Keyword(s):  
Animal Models ◽  
Olfactory Bulb ◽  
Neural Activity ◽  
Response Patterns ◽  
Clinical Tool ◽  
Nasal Bridge ◽  
Non Invasive ◽  
Wide Range ◽  
Human Animal ◽  
Olfactory Processing

ABSTRACTCurrent methods can, in a non-invasive manner, assess neural activity in all areas of the human brain but the olfactory bulb (OB). The OB is intimately involved in a long list of olfactory tasks, has been suggested to fulfill a role comparable to that of V1 and the thalamus in the visual system, and have been closely linked to a wide range of neuropathologies. Here we present a method for non-invasive recording of signals from the human OB with millisecond precision. We demonstrate that signals obtained via recordings from EEG electrodes at the nasal bridge represent responses from the olfactory bulb - recordings we term Electrobulbogram (EBG). The EBG is localized to the OB, is reliable, and follows response patterns demonstrated in non-human animal models. The EBG will aid future olfactory-related translational work but can also easily be implemented as an everyday clinical tool to detect pathology-related changes in human central olfactory processing in neurodegenerative diseases.

scholarly journals Effect of intervening lesions on amino acid distributions in rat olfactory cortex and olfactory bulb.

1980 ◽  
Vol 28 (11) ◽  
pp. 1157-1169 ◽  
Author(s):  
D A Godfrey ◽  
C D Ross ◽  
J A Carter ◽  
O H Lowry ◽  
F M Matschinsky
Keyword(s):  
Amino Acids ◽  
Olfactory Bulb ◽  
Granule Cells ◽  
Anterior Commissure ◽  
Piriform Cortex ◽  
Mitral Cell ◽  
Olfactory Cortex ◽  
Gamma Aminobutyric Acid ◽  
Lateral Olfactory Tract ◽  
Mapping Procedure

Levels of the proposed neurotransmitter amino acids glutamate, aspartate, gamma-aminobutyric acid (GABA), and glycine were measured within the layered structures of the olfactory bulb and olfactory cortex following unilateral transections of the lateral olfactory tract or of virtually all fiber tracts of the olfactory peduncle. Distributions of the amino acids on both lesion and control sides were examined and compared by means of a mapping procedure. The results suggest: 1) Glutamate and aspartate are specifically associated with mitral (and presumably also tufted) cell axons and terminals in the piriform cortex. The distribution of aspartate in the olfactory bulb is further suggestive of a specific association of aspartate with mitral cell dendrites and somata. 2) Glutamate might be specifically associated with some centrifugal fibers traveling to the olfactory bulb in or near the anterior commissure. 3) GABA might be specifically related to some certrifugal fibers to the olfactory bulb in addition to its prominent association with granule cells of the bulb. 4) Glycine is unlikely to play a prominent neurotransmitter role in either the olfactory bulb or olfactory cortex.

scholarly journals Binaral Interactions in the Rat Piriform Cortex

1997 ◽  
Vol 78 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Donald A. Wilson
Keyword(s):  
Olfactory Bulb ◽  
Piriform Cortex ◽  
Receptive Fields ◽  
Isoamyl Acetate ◽  
Response Patterns ◽  
Bilateral Stimulation ◽  
Contralateral Stimulation ◽  
Anterior Piriform Cortex ◽  
Single Unit Recordings ◽  
Ipsilateral Stimulation

Wilson, Donald A. Binaral interactions in the rat piriform cortex. J. Neurophysiol. 78: 160–169, 1997. Single-unit recordings were made from layer II/III anterior piriform cortex (aPCX) neurons in adult Wistar rats to examine odor response patterns to unilaterally and bilaterally delivered stimuli. Isoamyl acetate odor stimulation was presented either unilaterally through tubes inserted into the external nares, or bilaterally during unilateral olfactory bulb lidocaine infusions. Olfactory bulb multiunit or slow-wave activity was recorded simultaneously bilaterally to monitor selectivity of unilateral odor stimulation. The results demonstrate that 1) commissural input to aPCX neurons is sufficient to drive odor responses, and 2) aPCX neurons can be classified on the basis of spatial receptive field type. These receptive fields include cells that respond 1) selectively to ipsilateral stimulation, 2) selectively to contralateral stimulation, 3) to either ipsilateral or contralateral stimulation, and 4) selectively to bilateral stimulation. The potential functions of binaral convergence in the piriform cortex are discussed, and may include enhancement of perceived odor intensity and bilateral access to olfactory memory.

scholarly journals Tuning of ventral tenia tecta neurons of the olfactory cortex to distinct scenes of feeding behavior

2018 ◽  
Author(s):  
Kazuki Shiotani ◽  
Hiroyuki Manabe ◽  
Yuta Tanisumi ◽  
Koshi Murata ◽  
Junya Hirokawa ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Drinking Behavior ◽  
Piriform Cortex ◽  
Sensory Information ◽  
Afferent Input ◽  
Olfactory Cortex ◽  
Top Down ◽  
Behavioral Correlates ◽  
Drinking Behaviors

AbstractVentral tenia tecta (vTT) is a part of the olfactory cortex that receives both olfactory sensory signals from the olfactory bulb and top-down signals from the prefrontal cortex. To address the question whether and how the neuronal activity of the vTT is modulated by prefrontal cognitive processes such as attention, expectation and working memory that occurs during goal-directed behaviors, we recorded individual neuronal responses in the vTT of freely moving awake mice that performed learned odor-guided feeding and drinking behaviors. We found that the firing pattern of individual vTT cells had repeatable behavioral correlates such that the environmental and behavioral scene the mouse encountered during the learned behavior was the major determinant of when individual vTT neurons fired maximally. Furthermore, spiking activity of these scene cells was modulated not only by the present scene but also by the future scene that the mouse predicted. We show that vTT receives afferent input from the olfactory bulb and top-down inputs from the medial prefrontal cortex and piriform cortex.These results indicate that different groups of vTT cells are activated at different scenes and suggest that processing of olfactory sensory information is handled by different scene cells during distinct scenes of learned feeding and drinking behaviors. In other words, during the feeding and drinking behavior, vTT changes its working mode moment by moment in accord with the scene change by selectively biasing specific scene cells. The scene effect on olfactory sensory processing in the vTT has implications for the neuronal circuit mechanisms of top-down attention and scene-dependent encoding and recall of olfactory memory.

scholarly journals Non-invasive recording from the human olfactory bulb

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Behzad Iravani ◽  
Artin Arshamian ◽  
Kathrin Ohla ◽  
Donald A. Wilson ◽  
Johan N. Lundström
Keyword(s):  
Animal Models ◽  
Olfactory Bulb ◽  
Neural Activity ◽  
Response Patterns ◽  
Clinical Tool ◽  
Nasal Bridge ◽  
Non Invasive ◽  
Wide Range ◽  
Human Animal ◽  
Olfactory Processing

AbstractCurrent non-invasive neuroimaging methods can assess neural activity in all areas of the human brain but the olfactory bulb (OB). The OB has been suggested to fulfill a role comparable to that of V1 and the thalamus in the visual system and have been closely linked to a wide range of olfactory tasks and neuropathologies. Here we present a method for non-invasive recording of signals from the human OB with millisecond precision. We demonstrate that signals obtained via recordings from EEG electrodes at the nasal bridge represent responses from the human olfactory bulb - recordings we term Electrobulbogram (EBG). The EBG will aid future olfactory-related translational work but can also potentially be implemented as an everyday clinical tool to detect pathology-related changes in human central olfactory processing in neurodegenerative diseases. In conclusion, the EBG is localized to the OB, is reliable, and follows response patterns demonstrated in non-human animal models.

scholarly journals Odor hedonics coding in the vertebrate olfactory bulb

2021 ◽  
Vol 383 (1) ◽  
pp. 485-493 ◽  
Author(s):  
Florence Kermen ◽  
Nathalie Mandairon ◽  
Laura Chalençon
Keyword(s):  
Social Interaction ◽  
Olfactory Bulb ◽  
Physicochemical Properties ◽  
Olfactory Perception ◽  
Hedonic Value ◽  
Odor Hedonics ◽  
The Brain

AbstractWhether an odorant is perceived as pleasant or unpleasant (hedonic value) governs a range of crucial behaviors: foraging, escaping danger, and social interaction. Despite its importance in olfactory perception, little is known regarding how odor hedonics is represented and encoded in the brain. Here, we review recent findings describing how odorant hedonic value is represented in the first olfaction processing center, the olfactory bulb. We discuss how olfactory bulb circuits might contribute to the coding of innate and learned odorant hedonics in addition to the odorant’s physicochemical properties.

scholarly journals Book review: The prehistoric apprentice: Investigating apprenticeship, know-how and expertise in prehistoric technologies; L’apprenti préhistorique: Appréhender l’apprentissage, les savoir-faire et l’expertise à travers les productions techniques des soci

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Manek Kolhatkar
Keyword(s):  
Material Culture ◽  
Cultural Change ◽  
Spatial Organization ◽  
Raw Material ◽  
Cultural Norms ◽  
Technological Organization ◽  
Wide Range ◽  
French And English ◽  
Culture Variability

Describing cultural change and variability and inferring sociocultural dynamics about past people and communities may be among archaeology’s main goals as a field of practice. In this regard, the concept of skill has proved its usefulness to, time and again, expand the breath of archaeologists and lithic technologists’ analyses. It covers a wide range of applications, from apprenticeship, cognition, paleo-sociology, spatial organization. It is one of the main causes for material culture variability, up there with raw material constraints, design, technological organization or cultural norms. Yet, while skill has certainly been the focus of some research in the last decades, it remains quite peripheral, when considering how central the concept should be to technological inquiries. Whatever the reasons may be, this book, edited by Laurent Klaric and fully bilingual (French and English), aims at changing that, and argues for skill to become a central concern in lithic technology. Its chapters do so strongly and the end-result is a book that should become a reference for lithic technologists, whatever their research interests or schools of thought may be.

scholarly journals Faculty Teaching Practices and Perceptions: Comparative Analysis Based on Time Spent Lecturing

2017 ◽  
Vol 10 ◽  
pp. 27-44
Author(s):  
Gulnur Birol ◽  
Adriana Briseño-Garzón ◽  
Andrea Han
Keyword(s):  
Teaching Practices ◽  
Response Patterns ◽  
University Of British Columbia ◽  
Faculty Teaching ◽  
Wide Range ◽  
Baseline Information ◽  
Survey Responses ◽  
The University ◽  
Classroom Time ◽  
Large Research

The University of British Columbia-Vancouver (UBC-V) implemented a campus-wide survey of faculty teaching practices and perceptions. All 11 Faculties participated, resulting in a total of 1177 responses for an overall response rate of 24%. We compared response patterns of faculty who reported spending less than 25%, between 26-50%, between 51-75%, and more than 75% of classroom time lecturing. Using this breakdown, we analysed survey responses related to in and out-of-class practices and expectations for students, use of teaching assistant time, participation in professional development opportunities, and perceptions of whether the institution valued teaching. Participants across quadrants reported employing a wide range of teaching methods irrespective of years of experience and class size. Our findings outline the range of teaching practices employed by faculty at a large research-intensive Canadian institution and may provide baseline information for institutions of similar scale and focus.

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