Functional morphology of the primary olfactory centers in the brain of the hermit crab Coenobita clypeatus (Anomala, Coenobitidae)

Terrestrial hermit crabs of the genus Coenobita display strong behavioral responses to volatile odors and are attracted by chemical cues of various potential food sources. Several aspects of their sense of aerial olfaction have been explored in recent years including behavioral aspects and structure of their peripheral and central olfactory pathway. Here, we use classical histological methods and immunohistochemistry against the neuropeptides orcokinin and allatostatin as well as synaptic proteins and serotonin to provide insights into the functional organization of their primary olfactory centers in the brain, the paired olfactory lobes. Our results show that orcokinin is present in the axons of olfactory sensory neurons, which target the olfactory lobe. Orcokinin is also present in a population of local olfactory interneurons, which may relay lateral inhibition across the array of olfactory glomeruli within the lobes. Extensive lateral connections of the glomeruli were also visualized using the histological silver impregnation method according to Holmes-Blest. This technique also revealed the structural organization of the output pathway of the olfactory system, the olfactory projection neurons, the axons of which target the lateral protocerebrum. Within the lobes, the course of their axons seems to be reorganized in an axon-sorting zone before they exit the system. Together with previous results, we combine our findings into a model on the functional organization of the olfactory system in these animals

Master of Science

thesisThis thesis discusses the development of an olfactory display for the University of Utah TreadPort Virtual Environment (UUTVE). The goal of the UUTVE is to create a virtual environment that is as life like as possible by communicating to the user as many of the sensations felt in moving around in real the world as possible, while staying within the confines of the virtual environment's workspace. The UUTVE has a visual display, auditory display, a locomotion interface and wind display. With the wind display, it is possible to create an effective olfactory display that does not have some of the limitations associated with many of the current olfactory displays. The inclusion of olfactory information in virtual environments is becoming increasingly common as the effects of including an olfactory display show an increase in user presence. The development of the olfactory display for the UUTVE includes the following components: the physical apparatus for injecting scent particles into the air stream, the development of a Computational Fluid Dynamics (CFD) model with which to control the concentration of scent being sensed by the user, and user studies to verify the model and show as proof of concept that the wind tunnel can be used to create an olfactory display. The physical apparatus of the display consists of air atomizing nozzles, solenoids for controlling when the scents are released, containers for holding the scents and a pressurized air tank used to provide the required air to make the nozzles work. CFD is used model the wind flow through the TPAWT. The model of the wind flow is used to simulate how particles advect in the wind tunnel. These particle dispersion simulations are then used to create a piecewise model that is able to predict the scent's concentration behavior as the odor flows through the wind tunnel. The user studies show that the scent delivery system is able to display an odor to a person standing in the TPAWT. The studies also provided a way to measure the time it takes for a person to recognize an odor after it has been released into the air stream, and also the time it takes for a user to recognize that the odor is no longer present

S(C)ENTINEL - monitoring automated vehicles with olfactory reliability displays

Overreliance in technology is safety-critical and it is assumed that this could have been a main cause of severe accidents with automated vehicles. To ease the complex task of per- manently monitoring vehicle behavior in the driving en- vironment, researchers have proposed to implement relia- bility/uncertainty displays. Such displays allow to estimate whether or not an upcoming intervention is likely. However, presenting uncertainty just adds more visual workload on drivers, who might also be engaged in secondary tasks. We suggest to use olfactory displays as a potential solution to communicate system uncertainty and conducted a user study (N=25) in a high-fidelity driving simulator. Results of the ex- periment (conditions: no reliability display, purely visual reliability display, and visual-olfactory reliability display) comping both objective (task performance) and subjective (technology acceptance model, trust scales, semi-structured interviews) measures suggest that olfactory notifications could become a valuable extension for calibrating trust in automated vehicles

Behavioral Aspects of Apolipoprotein E Knockout Mice

Apolipoprotein E (apoE) is a lipid transporting protein that has been shown to play a vital role in nerve repair and remodeling. Previous studies have shown that apoE is highly expressed in human and mouse olfactory bulbs. ApoE deficiency in apolipoprotein E knockout (apoE-KO) mice leads to considerable delay in olfactory nerve repair and deficits in olfactory functioning. Olfactory function is necessary for a number of social behaviors in mice. Loss of olfaction can greatly reduce social behaviors. Since apoE-KO mice display olfactory dysfunction, this deficit may result in alterations in social behavior. Olfactory function was assessed in apoE-KO mice and wild type (WT) mice by using the odor cued taste avoidance test (OCTA). ApoE-KO mice were significantly less effective than WT mice in avoiding the odorant cued tastant solution. In order to determine if olfactory dysfunction disrupted social behavior, we used two standard social behavior tests: 1) pup retrieval test and 2) resident-intruder test. ApoE-KO mice performed poorly on both behavior tests. ApoE-KO mice display maternal behavior deficits such as fewer litters retrieved and lower nest quality scores. Furthermore, apoE-KO mice were less aggressive than WT individuals. These studies suggest that mice rely heavily upon olfactory communication for modification of social behaviors. ApoE is necessary for normal olfactory function in mice and may play a role in regulating social behaviors in mice

Development of a portable, multichannel olfactory display transducer

In this paper we report on the development of a simple, yet innovative multi-channel olfactory display. Unlike other sensory stimuli (specifically sight and sound), digital olfactory technology has yet to have wide-spread commercial success. Our proposed system will release up to 8 different liquid phase aromas (essential oils) using a thermal mechanism. The unit contains a speed controlled fan, temperature control of the heating element and a gas sensor to provide feedback to inform the release rate. It can be connected (via Bluetooth LE) to a tablet/computer to control the timing and intensity of the aroma. External measurements show that aromas can be detected within a few seconds of release and produce a broad range of intensities from low ppm to 10’s of ppm

Notch1 activity in the olfactory bulb is odour-dependent and contributes to olfactory behaviour

Notch signalling plays an important role in synaptic plasticity, learning and memory functions in both Drosophila and rodents. In this paper, we report that this feature is not restricted to hippocampal networks but also involves the olfactory bulb (OB). Odour discrimination and olfactory learning in rodents are essential for survival. Notch1 expression is enriched in mitral cells of the mouse OB. These principal neurons are responsive to specific input odorants and relay the signal to the olfactory cortex. Olfactory stimulation activates a subset of mitral cells, which show an increase in Notch activity. In Notch1cKOKln mice, the loss of Notch1 in mitral cells affects the magnitude of the neuronal response to olfactory stimuli. In addition, Notch1cKOKln mice display reduced olfactory aversion to propionic acid as compared to wildtype controls. This indicates, for the first time, that Notch1 is involved in olfactory processing and may contribute to olfactory behaviour

Olfaction-enhanced multimedia: Perspectives and challenges

This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 Springer VerlagOlfaction—or smell—is one of the last challenges which multimedia and multimodal applications have to conquer. Enhancing such applications with olfactory stimuli has the potential to create a more complex—and richer—user multimedia experience, by heightening the sense of reality and diversifying user interaction modalities. Nonetheless, olfaction-enhanced multimedia still remains a challenging research area. More recently, however, there have been initial signs of olfactory-enhanced applications in multimedia, with olfaction being used towards a variety of goals, including notification alerts, enhancing the sense of reality in immersive applications, and branding, to name but a few. However, as the goal of a multimedia application is to inform and/or entertain users, achieving quality olfaction-enhanced multimedia applications from the users’ perspective is vital to the success and continuity of these applications. Accordingly, in this paper we have focused on investigating the user perceived experience of olfaction-enhanced multimedia applications, with the aim of discovering the quality evaluation factors that are important from a user’s perspective of these applications, and consequently ensure the continued advancement and success of olfaction-enhanced multimedia applications

Integrating Olfaction in a Robotic Telepresence Loop

In this work we propose enhancing a typical robotic telepresence architecture by considering olfactory and wind flow information in addition to the common audio and video channels. The objective is to expand the range of applications where robotics telepresence can be applied, including those related to the detection of volatile chemical substances (e.g. land-mine detection, explosive deactivation, operations in noxious environments, etc.). Concretely, we analyze how the sense of smell can be integrated in the telepresence loop, covering the digitization of the gases and wind flow present in the remote environment, the transmission through the communication network, and their display at the user location. Experiments under different environmental conditions are presented to validate the proposed telepresence system when localizing a gas emission leak at the remote environment.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Single-cell transcriptional profiles and spatial patterning of the mammalian olfactory epithelium

In order to gain insights into the regulatory control of neuronal diversity in the mammalian olfactory system, we have identified the transcriptional profile of individual olfactory neurons. A single cell microarray strategy was performed to search for candidate genes involved in the molecular specification of dorso-ventral zones of olfactory receptor (OR) expression. Several transcripts were identified that display differential expression in distinct OR zones, including a novel family of genes, the Lozenge-like (Lzl) genes which share sequence consensus motifs with Lozenge, a transcription factor involved in the patterning of the Drosophila olfactory and visual systems. © UBC Press

The sweet smell of success: Enhancing multimedia applications with olfaction

This is the Post-Print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ACMOlfaction, or smell, is one of the last challenges which multimedia applications have to conquer. As far as computerized smell is concerned, there are several difficulties to overcome, particularly those associated with the ambient nature of smell. In this article, we present results from an empirical study exploring users' perception of olfaction-enhanced multimedia displays. Findings show that olfaction significantly adds to the user multimedia experience. Moreover, use of olfaction leads to an increased sense of reality and relevance. Our results also show that users are tolerant of the interference and distortion effects caused by olfactory effect in multimedia