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Journal of Comparative Physiology. A,... Jul 2023Using odors to find food and mates is one of the most ancient and highly conserved behaviors. Arthropods from flies to moths to crabs use broadly similar strategies to... (Review)
Review
Using odors to find food and mates is one of the most ancient and highly conserved behaviors. Arthropods from flies to moths to crabs use broadly similar strategies to navigate toward odor sources-such as integrating flow information with odor information, comparing odor concentration across sensors, and integrating odor information over time. Because arthropods share many homologous brain structures-antennal lobes for processing olfactory information, mechanosensors for processing flow, mushroom bodies (or hemi-ellipsoid bodies) for associative learning, and central complexes for navigation, it is likely that these closely related behaviors are mediated by conserved neural circuits. However, differences in the types of odors they seek, the physics of odor dispersal, and the physics of locomotion in water, air, and on substrates mean that these circuits must have adapted to generate a wide diversity of odor-seeking behaviors. In this review, we discuss common strategies and specializations observed in olfactory navigation behavior across arthropods, and review our current knowledge about the neural circuits subserving this behavior. We propose that a comparative study of arthropod nervous systems may provide insight into how a set of basic circuit structures has diversified to generate behavior adapted to different environments.
Topics: Animals; Arthropods; Olfactory Pathways; Smell; Odorants; Brain
PubMed: 36658447
DOI: 10.1007/s00359-022-01611-9 -
Current Allergy and Asthma Reports Mar 2023Olfactory dysfunction contributes to the psychopathology of mental illness. In this review, we describe the neurobiology of olfaction, and the most common olfactory... (Review)
Review
PURPOSE OF REVIEW
Olfactory dysfunction contributes to the psychopathology of mental illness. In this review, we describe the neurobiology of olfaction, and the most common olfactory alterations in several mental illnesses. We also highlight the role, hitherto underestimated, that the olfactory pathways play in the regulation of higher brain functions and its involvement in the pathophysiology of psychiatric disorders, as well as the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in psychiatric conditions.
RECENT FINDINGS
The olfactory deficits present in anxiety, depression, schizophrenia or bipolar disorder consist of specific alterations of different components of the sense of smell, mainly the identification of odours, as well as the qualifications of their hedonic valence (pleasant or unpleasant). Epidemiological findings have shown that both environmental factors, such as air pollutants, and inflammatory disease of the upper respiratory tract, can contribute to an increased risk of mental illness, at least in part, due to peripheral inflammatory mechanisms of the olfactory system. In this review, we describe the neurobiology of olfaction, and the most common olfactory function alterations in several psychiatric conditions and its role as a useful symptom for the differential diagnosis. We also highlight the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in these psychiatric conditions.
Topics: Humans; Smell; Mental Disorders; Olfaction Disorders; Emotions; Inflammation
PubMed: 36696016
DOI: 10.1007/s11882-023-01068-z -
Gerontology 2015Decreased olfactory function is very common in the older population, being present in >50% of individuals aged between 65 and 80 years and in 62-80% of those >80 years... (Review)
Review
Decreased olfactory function is very common in the older population, being present in >50% of individuals aged between 65 and 80 years and in 62-80% of those >80 years of age. Smell dysfunction significantly influences physical well-being, quality of life, nutritional status as well as everyday safety and is associated with increased mortality. Multiple factors contribute to age-related olfactory sensory loss, including nasal engorgement, cumulative damage of the olfactory epithelium from environmental insults, a reduction in mucosal metabolizing enzymes, sensory loss of receptor cells to odorants, and changes in neurotransmitter and neuromodulator systems. In addition, structural and functional abnormalities of the olfactory epithelium, olfactory bulb, central olfactory cortex, and basic olfactory circuitry, which are related to the neuronal expression of aberrant proteins in these areas, may result in olfactory sensory impairment in aging and neurodegenerative diseases. Impaired odour identification is associated with a decrease in cognitive abilities and memory decline. A reduction in the sense of smell is considered to potentially represent an early and important warning of neurodegenerative disorders, particularly of Parkinson's disease and Alzheimer's disease, and, in mild cognitive impairment, olfactory impairment may herald progression to dementia. Further investigations of the potential role of olfactory dysfunction in the early diagnosis and treatment of neurodegenerative diseases are warranted.
Topics: Age Factors; Aged; Aged, 80 and over; Humans; Olfaction Disorders; Smell
PubMed: 25968962
DOI: 10.1159/000381619 -
Handbook of Clinical Neurology 2019Despite garnering minimal attention from the medical community overall, olfaction is indisputably critical in the manner in which we as humans interact with our... (Review)
Review
Despite garnering minimal attention from the medical community overall, olfaction is indisputably critical in the manner in which we as humans interact with our surrounding environment. As the initial anatomical structure in the olfactory pathway, the nasal airway plays a crucial role in the transmission and perception of olfactory stimuli. The goal of this chapter is to provide a comprehensive overview of olfactory disturbances as it pertains to the sinonasal airway. This comprises an in-depth discussion of clinically relevant nasal olfactory anatomy and physiology, classification systems of olfactory disturbance, as well as the various etiologies and pathophysiologic mechanisms giving rise to this important disease entity. A systematic clinical approach to the diagnosis and clinical workup of olfactory disturbances is also provided in addition to an extensive review of the medical and surgical therapeutic modalities currently available.
Topics: Chronic Disease; Humans; Nasal Cavity; Nose; Olfaction Disorders; Olfactory Bulb; Smell
PubMed: 31604553
DOI: 10.1016/B978-0-444-63855-7.00018-6 -
Neurological Sciences : Official... Jul 2023To date, there are quite a few studies assessing olfaction and gustation in blindness, with great variability in sample size, participants' age, blindness onset and... (Review)
Review
To date, there are quite a few studies assessing olfaction and gustation in blindness, with great variability in sample size, participants' age, blindness onset and smell and taste evaluation methods. Indeed, the evaluation of olfactory and gustatory performance can differ depending on several factors, including cultural differences. Therefore, here we analysed through a narrative review, all the works reporting a smell and taste assessment in blind individuals during the last 130 years, trying to summarize and address the knowledge in this field.
Topics: Humans; Smell; Taste; Olfaction Disorders; Taste Perception; Blindness
PubMed: 36913147
DOI: 10.1007/s10072-023-06734-8 -
Trends in Genetics : TIG Feb 2023Gene-editing technologies have revolutionized the field of mosquito sensory biology. These technologies have been used to knock in reporter genes in-frame with neuronal... (Review)
Review
Gene-editing technologies have revolutionized the field of mosquito sensory biology. These technologies have been used to knock in reporter genes in-frame with neuronal genes and tag specific mosquito neurons to detect their activities using binary expression systems. Despite these advances, novel tools still need to be developed to elucidate the transmission of olfactory signals from the periphery to the brain. Here, we propose the development of a set of tools, including novel driver lines as well as sensors of neuromodulatory activities, which can advance our knowledge of how sensory input triggers behavioral outputs. This information can change our understanding of mosquito neurobiology and lead to the development of strategies for mosquito behavioral manipulation to reduce bites and disease transmission.
Topics: Animals; Culicidae; Smell; Gene Editing; Neurons
PubMed: 36414481
DOI: 10.1016/j.tig.2022.10.007 -
Neuron Dec 2011Neuroethology utilizes a wide range of multidisciplinary approaches to decipher neural correlates of natural behaviors associated with an animal's ecological niche. By... (Review)
Review
Neuroethology utilizes a wide range of multidisciplinary approaches to decipher neural correlates of natural behaviors associated with an animal's ecological niche. By placing emphasis on comparative analyses of adaptive and evolutionary trends across species, a neuroethological perspective is uniquely suited to uncovering general organizational and biological principles that shape the function and anatomy of the nervous system. In this review, we focus on the application of neuroethological principles in the study of insect olfaction and discuss how ecological environment and other selective pressures influence the development of insect olfactory neurobiology, not only informing our understanding of olfactory evolution but also providing broader insights into sensory processing.
Topics: Animals; Biological Evolution; Insecta; Olfactory Pathways; Smell
PubMed: 22153368
DOI: 10.1016/j.neuron.2011.11.003 -
Chemical Senses Feb 2018The field of chemical senses has made major progress in understanding the cellular mechanisms of olfaction and taste in the past 2 decades. However, the molecular... (Review)
Review
The field of chemical senses has made major progress in understanding the cellular mechanisms of olfaction and taste in the past 2 decades. However, the molecular understanding of odor and taste recognition is still lagging far behind and will require solving multiple structures of the relevant full-length receptors in complex with native ligands to achieve this goal. However, the development of multiple complimentary strategies for the structure determination of G protein-coupled receptors (GPCRs) makes this goal realistic. The common conundrum of how multi-specific receptors that recognize a large number of different ligands results in a sensory perception in the brain will only be fully understood by a combination of high-resolution receptor structures and functional studies. This review discusses the first steps on this pathway, including biochemical and physiological assays, forward genetics approaches, molecular modeling, and the first steps towards the structural biology of olfactory and taste receptors.
Topics: Animals; Humans; Receptors, G-Protein-Coupled; Smell; Structure-Activity Relationship; Taste Buds; Taste Perception
PubMed: 29342245
DOI: 10.1093/chemse/bjx083 -
The Yale Journal of Biology and Medicine Mar 2018Recent advances in genetic tools and optical imaging technology have allowed rodent and researchers to explore the relationship between serotonergic modulation and... (Review)
Review
Recent advances in genetic tools and optical imaging technology have allowed rodent and researchers to explore the relationship between serotonergic modulation and olfactory processing at a mechanistic level previously unfeasible. Here, I review the basic organization of olfactory and serotonergic systems in both rodents and and draw comparisons where similarities exist. I discuss circuit level models that explain many of serotonin's effects on olfactory responses in the olfactory system's inputs and outputs. Finally, I discuss models of integration within wide-field centrifugal neurons to emphasize the importance of studying serotonergic neurons directly to build more realistic models of olfactory and modulatory interactions.
Topics: Animals; Insecta; Paracrine Communication; Rodentia; Serotonergic Neurons; Serotonin; Smell
PubMed: 29599654
DOI: No ID Found -
Current Biology : CB Apr 2023New research indicates that the odor-evoked responses of human olfactory receptors can be enhanced via the non-competitive binding of an allosteric modulator. This...
New research indicates that the odor-evoked responses of human olfactory receptors can be enhanced via the non-competitive binding of an allosteric modulator. This modulatory mechanism adds an additional layer of complexity to the peripheral encoding of odors.
Topics: Humans; Olfactory Receptor Neurons; Odorants; Receptors, Odorant; Smell
PubMed: 37098335
DOI: 10.1016/j.cub.2023.03.046