Olfactory system

The mammalian olfactory system shows an exceptional ability for rapid and accurate decoding of both the identity and concentration of odorants. In a given scene, only a handful out of millions of possible odorants are present. Yet, the mammals can effectively distinguish these odorants using the dimensionally-reduced representation provided by olfactory receptor neurons. To account for this capability, normative compressed sensing models have been proposed by previous studies. However, these models do not map cleanly onto the unique anatomy and physiology of the olfactory bulb, nor have they d

…of AD proposes that AD begins in the olfactory system, progressing then through the lateral entorhinal cortex to the hippocampus, whereupon symptoms of dementia become apparent. Intracerebral inoculation of healthy rodents with oligomeric amyloid-beta(1-42) results in impairments of hippocampal information processing and storage (doi: 10.3389/fnbeh.2015.00103).To what extent this also affec

In the olfactory system, the glomeruli of the olfactory bulb define the first synapse processing odour information in the brain. Here, many synapses are established between olfactory sensory neurons (OSNs) and olfactory bulb neurons. Xenopus tropicalis tadpoles provide an excellent experimental platform to investigate the molecular mechanisms of synaptic transmission in vivo due to its experimental accessibility and transparency. We investigated long-lasting depolarizations (LLDs) occurring in the glomerular layer of the olfactory bulb by measuring changes in the local field potential. We reco

Modification of the olfactory system can dramatically influence emotion and it is well accepted that mice with olfactory impairments develop pseudo-depressive symptoms (Yuan. M. et al, 2020) and microbiota dysregulation (Shuai-Ming Zhu et al, 2024). On this backdrop, our research is currently focusing on the therapeutic potential of exploiting the olfactory system in mood-related disorders. Different odors can exert anxiolytic and/or antidepressant-like effects in several depression models. To better understand the functional relationships between odors, emotion, microbiota and gut physiology

…tissues, such as lung, cardiovascular system, skin and central nervous system (CNS). We examined in two species of male mice, whether O3 could alters olfactory behavior and cellular properties in the olfactory system. For this purpose, mice were exposed to O3 at a concentration foun

…has not been found yet in the olfactory system. This is because odors constitute discrete objects that do not vary along a specific physical dimension. Here, we have developed a method to reveal the receptive field (RF) of anterior piriform cortex (aPC) neurons. The RF is defined as the glomeruli set that affects the recorded aPC neuron. We found that, on average, an aPC neuron RF com

…odor to track back to its source, the olfactory system must compare information from different filaments over relatively long timescales. Second, to remain on high alert to unexpected changes, su

…Despite decades of attention in systems neuroscience, many questions persist regarding how sensory codes adapt to these different variables. Here, we study this problem in the olfactory system. We focus on a neural circuit (the bulb) where incoming odor inputs are integrated with extensive contextual feedback from areas of the brain involved in multi-sensory association, attention, memory, and decision- making. While most

In all sensory systems, arrays of receptors respond to stimuli over both space and time. Whether and how the precise temporal pattern of receptor activation impacts the activity of downstream brain regions remains unclear. In the olfactory system, odors activate stereotyped spatiotemporal sequences of olfactory bulb (OB) glomeruli, whose responses reflect the activity of olfactory receptor neurons. These glomeruli project via OB mitral and tufted (M/T) cells to downstream piriform cortex (PCx), forming a shallow circuit through which to assess how temporal patterns of receptor activity are enc

…several brain areas of the limbic system, such as the hippocampus (HP) and lateral entorhinal cortex (LEC). They are modulated by multiple sensory systems. During development, the olfactory system might have a particular impact on these areas in mice that at birth are blind, deaf, do not whisker and have poor motor abilities. We previously showed that neonatal olfactory activation boosts the oscillatory entrainment of LEC via mono-and polysynaptic projections from the olfactory bulb (OB). However, the long-lasting impact of olfactory

Representational drift has been observed in different parts of the nervous system. Nevertheless a complete mechanistic understanding about it is missing. In a recent experimental study in the olfactory system, recordings from the piriform cortex demonstrate drift in the representation of a single olfactory stimulus, despite apparently stable odor identification. Such drift is characterized by a decay in the self-similarity of the stimulus representation vector as a function of the time between the recordings. Additionally, the rate of the decay was shown to be smaller for more frequent stimuli

We use the olfactory system and forebrain of (adult) zebrafish as a model to analyze how relevant information is extracted from sensory inputs, how information is stored in memory circuits, and how sensory inputs inform behavior. A series of recent findings provides evidence that inhibition has not only homeostatic functions in neuronal circuits but makes highly specific, instructive contributions to behaviorally relevant computations in different brain regions. These observations imply that the connectivity among excitatory and inhibitory neurons exhibits essential higher-order structure that

I will argue that the circuit architecture of the early olfactory system provides an adaptive, efficient mechanism for compressing the vast space of odor mixtures into the responses of a small number of sensors. In this view, the olfactory sensory repertoire employs a disordered code to compress a high dimensional olfactory space into a low dimensional receptor response space while preserving distance relations between odors. The resulting representation is dynamically adapted to efficiently encode the changing environment of volatile molecules. I will show that this adaptive combinatorial

In the olfactory system, cholinergic modulation has been associated with contrast modulation and changes in receptive fields in the olfactory bulb, as well the learning of odor associations in the olfactory cortex. Computational modeling and behavioral studies suggest that cholinergic modulation could improve sensory processing and learning while preventing pro-active interference when task demands are high. However, how sensory inputs and/or learning regulate incoming modulation has not yet been elucidated. We here use a computational model of the olfactory bulb, piriform cortex (PC) and hori

…information is decoded from the olfactory system