Ex vivo functional characterization of mouse olfactory bulb projection neurons reveals a heterogenous continuum

eNeuro, Journal Year: 2025, Volume and Issue: 12(3), P. ENEURO.0407 - 24.2025

Published: Feb. 4, 2025

Mitral cells (MCs) and tufted (TCs) in the olfactory bulb (OB) act as an input convergence hub transmit information to higher areas. Since first characterized, they have been classed distinct projection neurons based on size location: laminarly arranged MCs with a diameter larger than 20 µm mitral layer (ML) smaller TCs spread across both ML external plexiform layers (EPL). Recent vivo work has shown that these encode complementary information, akin parallel channels other sensory systems. Yet, many ex studies still collapse them into single class, mitral/tufted, when describing their physiological properties impact circuit function. Using immunohistochemistry whole-cell patch-clamp electrophysiology fixed or acute slices from adult mice, we attempted align data test soma size-based classifier of bulbar using passive intrinsic firing properties. We found there is no clear separation between cell types active Rather, heterogeneous continuum three loosely clustered subgroups: EPL, putative ML. These findings illustrate large functional heterogeneity present within OB complement existing literature highlighting how systems preponderant possibly used decode complex information.

Language: Английский

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Strikingly different neurotransmitter release strategies in dopaminergic subclasses

Published: Feb. 10, 2025

Neuronal function is intimately tied to axodendritic polarity. Neurotransmitter release, for example, usually the role of axon. There are widespread exceptions this rule, however, including many mammalian neuronal types that can release neurotransmitter from their dendrites. In mouse olfactory bulb, closely related subclasses dopaminergic interneuron differ markedly in polarity, with one subtype lacking an axon entirely. These axon-bearing and anaxonic have distinct developmental profiles sensory responses, but how fundamental polarity differences translate functional outputs remains entirely unknown. Here, we provide anatomical evidence strategies among these subtypes: cells dendrites, while neurons exclusively intermittently myelinated structural linked a clear distinction: anaxonic, not capable self-inhibition. Our findings suggest variations produce striking distinctions outputs, even may play separate roles information processing.

Language: Английский

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Strikingly different neurotransmitter release strategies in dopaminergic subclasses

Published: Feb. 10, 2025

Neuronal function is intimately tied to axodendritic polarity. Neurotransmitter release, for example, usually the role of axon. There are widespread exceptions this rule, however, including many mammalian neuronal types that can release neurotransmitter from their dendrites. In mouse olfactory bulb, closely related subclasses dopaminergic interneuron differ markedly in polarity, with one subtype lacking an axon entirely. These axon-bearing and anaxonic have distinct developmental profiles sensory responses, but how fundamental polarity differences translate functional outputs remains entirely unknown. Here, we provide anatomical evidence strategies among these subtypes: cells dendrites, while neurons exclusively intermittently myelinated structural linked a clear distinction: anaxonic, not capable self-inhibition. Our findings suggest variations produce striking distinctions outputs, even may play separate roles information processing.

Language: Английский

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Olfactory bulb interneurons – The developmental timeline and targeting defined by embryonic neurogenesis

Molecular and Cellular Neuroscience, Journal Year: 2025, Volume and Issue: unknown, P. 104007 - 104007

Published: March 1, 2025

Language: Английский

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Arx revisited: involved in the development of GABAergic interneurons

Frontiers in Cell and Developmental Biology, Journal Year: 2025, Volume and Issue: 13

Published: March 28, 2025

The aristaless-related homeobox (Arx) transcription factor, located on the X chromosome, has been implicated in a wide range of neurological disorders, including intellectual disability and epilepsy, as well diabetes pancreatic developmental disorders. In mouse brain, Arx is expressed not only olfactory bulb (OB) cerebral cortex progenitor cells but also these gamma-aminobutyric acid (GABA)-releasing interneurons. initial study, constitutive knockout (KO) mice showed aberrant migration reduction GABAergic interneurons neonatal OB. However, KO with perinatal lethality preclude further analysis adolescent or adult mice. To overcome this, Arx-floxed have crossed Cre driver to generate conditional selective deletion distinct interneuron progenitors. These studies identified key transcriptional regulator involved generation, fate determination, cortical This review focuses critical role development OB cortex, discusses differences mutant-based abnormality between mutants human patients.

Language: Английский

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Basal forebrain GABAergic innervation of olfactory bulb periglomerular interneurons

The Journal of Physiology, Journal Year: 2019, Volume and Issue: 597(9), P. 2547 - 2563

Published: March 28, 2019

Basal forebrain long-range projections to the olfactory bulb are important for sensitivity and odour discrimination. Using optogenetics, it was confirmed that basal afferents mediate IPSCs on granule deep short axon cells. It also shown they selectively innervate specific subtypes of periglomerular (PG) Three different type 2 PG cells receive GABAergic from but not other Type 1 cells, in contrast, do inputs inhibition These results shed new light complexity specificity glomerular inhibitory circuits, as well their modulation by forebrain.Olfactory circuits dominated multiple pathways finely tune activity mitral tufted principal neurons, regulate Granule interglomerular lateral between cells' dendrites whereas diverse intraglomerular apical dendrites. Deep form broad intrabulbar both populations interneurons. Little is known about extrabulbar control these various We examined this question using patch-clamp recordings optogenetics slices transgenic mice. showed axonal emanating neurons densely project all layers bulb. provide a prominent synaptic input selective Specifically, three subclasses robust target-specific have little local interactions with In innervated fibres interact Thus, attention-regulated previously overlooked further defines interneuron subclasses.

Language: Английский

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PBX1 acts as terminal selector for olfactory bulb dopaminergic neurons

Development, Journal Year: 2020, Volume and Issue: 147(8)

Published: March 10, 2020

ABSTRACT Neuronal specification is a protracted process that begins with the commitment of progenitor cells and culminates generation mature neurons. Many transcription factors are continuously expressed during this but it presently unclear how these modify their targets as transition through different stages specification. In olfactory bulb adult neurogenesis, factor PBX1 controls neurogenesis in survival migrating neuroblasts. Here, we show that, at later differentiation stages, also acts terminal selector for dopaminergic neuron fate. required morphological maturation neurons to repress alternative interneuron fates, findings expand known repertoire terminal-selector actions. Finally, reveal temporal diversification functions neuronal achieved, least part, dynamic regulation splicing. Caenorhabditis elegans, PBX/CEH-20 selector, which suggests an ancient role PBX

Language: Английский

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Short-term plasticity in glomerular inhibitory circuits shapes olfactory bulb output

Journal of Neurophysiology, Journal Year: 2020, Volume and Issue: 123(3), P. 1120 - 1132

Published: Jan. 29, 2020

Short-term plasticity is a fundamental synaptic property thought to underlie memory and neural processing. The glomerular microcircuit comprises complex excitatory inhibitory interactions transmits olfactory nerve signals the output neurons, mitral/tufted cells (M/TCs). major interneurons, short axon (SACs) periglomerular (PGCs), both provide feedforward feedback inhibition M/TCs have reciprocal synapses between each other. Olfactory input episodically driven by sniffing. We hypothesized that frequency-dependent short-term within these circuits could influence sent higher-order networks. To assess in MC outputs, we virally delivered channelrhodopsin-2 (ChR2) glutamic acid decarboxylase-65 promotor (GAD2-cre) or tyrosine hydroxylase promoter (TH-cre) mice selectively activated one of two populations while recording from other population MCs. Selective activation TH-ChR2-expressing SACs inhibited all recorded GAD2-green fluorescent protein(GFP)-expressing presumptive PGC cells, GAD2-ChR2 TH-GFP-expressing SACs, indicating connections. SAC GAD2-expressing was significantly facilitated at 5-10 Hz frequencies. In contrast, cell TH-expressing activation-frequency independent. Both MCs also exhibited plasticity, pronounced 5-20 range corresponding investigative sniffing frequency ranges. paired electrical stimulations, synapse able markedly suppress spiking. These data suggest across ranges may differentially regulate intra- interglomerular dynamically shape downstream targets.NEW & NOTEWORTHY modulates strength based on preceding activity synapse. rodent olfaction, sensory arrives rates ranging quiescent respiration (1-2 Hz) through (5-10 Hz). Here show networks are exquisitely sensitive frequencies exhibit proportional This indicates modulated episodic input.

Language: Английский

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Unraveling the Role of Dopaminergic and Calretinin Interneurons in the Olfactory Bulb

Frontiers in Neural Circuits, Journal Year: 2021, Volume and Issue: 15

Published: Oct. 8, 2021

The perception and discriminating of odors are sensory activities that an integral part our daily life. first brain region where processed is the olfactory bulb (OB). Among different cell populations make up this area, interneurons play essential role in activity. Moreover, probably because their activity, they represent exception compared to other parts brain, since OB continuously generated postnatal adult period. In review, we will focus on periglomerular (PG) cells which a class found glomerular layer OB. These can be classified into distinct subtypes based neurochemical nature, neurotransmitter calcium-binding proteins expressed by these cells. Dopaminergic (DA) calretinin (CR) among newly important physiology OB, DA involved processing adaptation bulbar network external conditions. main appears inhibition glutamate release from fibers. Calretinin best morphologically characterized PG but little known about function except for inhibitory effect noisy random excitatory signals arriving at neurons. mainly describe electrophysiological properties related excitability profiles CR cells, with particular view differences characterize mature stages neurogenesis.

Language: Английский

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Heterogeneity of tyrosine hydroxylase expressing neurons in the main olfactory bulb of the mouse

Neuroscience Research, Journal Year: 2019, Volume and Issue: 157, P. 15 - 33

Published: Oct. 17, 2019

Language: Английский

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