Circuit formation and sensory perception in the mouse olfactory system

Frontiers in Neural Circuits, Journal Year: 2024, Volume and Issue: 18

Published: Feb. 16, 2024

In the mouse olfactory system, odor information is converted to a topographic map of activated glomeruli in bulb (OB). Although arrangement genetically determined, glomerular structure plastic and can be modified by environmental stimuli. If pups are exposed particular odorant, responding become larger recruiting dendrites connecting projection neurons interneurons. This imprinting not only increases sensitivity odor, but also imposes positive quality on imprinted memory. External represented as an OB transmitted cortex (OC) amygdala for decision making elicit emotional behavioral outputs using two distinct neural pathways, innate learned. Innate circuits start work right after birth, whereas learned functional later on. this paper, recent progress will summarized study circuit formation perception mice. We propose new hypotheses timing gating activity relation respiration cycle.

Language: Английский

---

Pheromone Sensing in Mammals: A Review of the Vomeronasal System

Anatomia, Journal Year: 2023, Volume and Issue: 2(4), P. 346 - 413

Published: Nov. 9, 2023

This review addresses the role of chemical communication in mammals, giving special attention to vomeronasal system pheromone-mediated interactions. The influences many social and sexual behaviors, from reproduction species recognition. Interestingly, this shows greater evolutionary variability compared olfactory system, emphasizing its complex nature need for thorough research. discussion starts with foundational concepts chemocommunication, progressing a detailed exploration systems. neuroanatomy stands contrast that system. Further, sensory part known as organ, integration center information, called accessory bulb, receive comprehensive coverage. Secondary projections both systems attention, especially relation dual hypothesis. concludes by examining organization four distinct mammalian groups: rodents, marsupials, herpestids, bovids. aim is highlight unique morphofunctional differences resulting adaptive changes each group experienced.

Language: Английский

---

Target-specific control of olfactory bulb periglomerular cells by GABAergic and cholinergic basal forebrain inputs

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Feb. 28, 2022

The olfactory bulb (OB), the first relay for odor processing in brain, receives dense GABAergic and cholinergic long-range projections from basal forebrain (BF) nuclei that provide information about internal state behavioral context of animal. However, targets, impact, dynamic these afferents are still unclear. How BF synaptic inputs modulate activity diverse subtypes periglomerular (PG) interneurons using optogenetic stimulation loose cell-attached or whole-cell patch-clamp recording OB slices adult mice were studied this article. potently blocked PG cells firing except a minority calretinin-expressing which GABA release elicited spiking. Parallel excited previously overlooked cell subtype via activation M1 muscarinic receptors. Low-frequency axons drove persistent cells, thereby increasing tonic inhibition principal neurons. Taken together, findings suggest modality-specific can orchestrate glomeruli multiple, potentially independent, inhibitory excitatory target-specific pathways.

Language: Английский

---

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

---

Frequency-dependent centrifugal modulation of the activity of different classes of mitral and tufted cells in olfactory bulb

Journal of Neurophysiology, Journal Year: 2023, Volume and Issue: 129(6), P. 1515 - 1533

Published: May 24, 2023

Neuronal circuits in the olfactory bulb closely modulate output activity. Activation of GABAergic from HDB to has both direct and indirect action differentially across five classes M/TC bulbar neurons. The net effect enhances excitability deeper neurons as frequency increases, altering relative inhibition-excitation balance circuits. We hypothesize that this sharpens tuning specificity M/TCs odors during sensory processing.

Language: Английский

---

The Response Dynamics and Function of Cholinergic and GABAergic Neurons in the Basal Forebrain During Olfactory Learning

Frontiers in Cellular Neuroscience, Journal Year: 2022, Volume and Issue: 16

Published: July 27, 2022

Modulation of neural circuits is essential for flexible sensory perception and decision-making in a changing environment. Cholinergic GABAergic projections to the olfactory system from horizontal limb diagonal band Broca (HDB) basal forebrain are crucial odor detection learning. Although studies have demonstrated that HDB neurons respond during learning, how cholinergic differ their response dynamics roles learning remains unclear. In this study, we examined profiles these two subpopulations passive exposure associative We show excitatory responses both tended habituate repeated exposure. However, while habituated were also observed go-go task, there was no such habituation neurons. Moreover, S+ S- trials diverged once mice learned go/no-go task. Furthermore, chemogenetic inactivation impaired discrimination. Together, findings suggest reflect attention positive reinforcement may regulate discrimination via top-down inputs system.

Language: Английский

---

Projection neurons are necessary for the maintenance, but not for the assembly, of the mouse olfactory circuit

eLife, Journal Year: 2024, Volume and Issue: 13

Published: Jan. 17, 2024

The assembly and maintenance of neural circuits is crucial for proper brain function. Although the has been extensively studied, much less understood about mechanisms controlling their as animals mature. In olfactory system, axons sensory neurons (OSNs) expressing same odor receptor converge into discrete synaptic structures bulb (OB) called glomeruli, forming a stereotypic map. OB projection neurons, mitral tufted cells (M/Ts), have single dendrite that branches glomerulus, where they make synapses with OSNs. We used genetic method to progressively eliminate vast majority M/T in early postnatal mice, observed proceeded normally. However, became adults apical remaining M/Ts grew multiple innervated several OSNs receptors projected disrupting Moreover, ablating adult also resulted similar structural changes projections from Interestingly, ability these mice detect odors was relatively preserved despite only having 1–5% transmitting odorant information brain, highly disrupted OB. These results indicate reduced number does not affect normal circuit, but induces instability circuitry animals.

Language: Английский

---

Robust encoding of sub-sniff temporal information in the mouse olfactory bulb

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 29, 2024

Summary The sensory world is highly dynamic, and the temporal structure of stimuli contains rich information about environment. Odour plumes are shaped by complex airflow that imprint nature spatial organisation olfactory environment onto their dynamics. Whilst insects mammals alike can discern high-frequency information, how properties represented in brain remains largely unknown. Here, we presented temporally systematically varying odour whilst electrically recording from output neurons mouse bulb, mitral tufted cells (MTC). We found aspects could readily be read out MTC responses, with a resolution up to 20 ms. Remarkably, representation was virtually identical across three different odours. To understand which features encoded, developed single-cell model accurately describing both population responses. Temporal receptive fields MTCs translated between odours, indicating tuning quality dynamics partially separable. Together, this suggests stereotypical projection serve as an entry point into dissecting mechanisms underlying extracted fluctuating plumes.

Language: Английский

---

Cell type-specific and frequency-dependent centrifugal modulation in olfactory bulb output neurons in vivo

Journal of Neurophysiology, Journal Year: 2024, Volume and Issue: 131(6), P. 1226 - 1239

Published: May 1, 2024

Mitral/tufted cells (M/TCs) form complex local circuits with interneurons in the olfactory bulb and are powerfully inhibited by these interneurons. The horizontal limb of diagonal band Broca (HDB), only GABAergic/inhibitory source centrifugal circuit bulb, is known to target interneurons, we have shown targeting also glutamatergic neurons vitro. However, net efficacy under different patterns activation vivo relative balance between various targeted intact was focus this study. Here channelrhodopsin-2 (ChR2) expressed HDB GABAergic investigate short-term plasticity HDB-activated disinhibitory rebound excitation M/TCs. Optical increased spontaneous M/TC firing without odor presentation odor-evoked firing. induced (burst or cluster spiking) all classes This frequency dependent, facilitation at higher stimulation (5 Hz above). frequency-dependent regulation more potent deeper layer M/TCs compared superficial In neural inhibition plays a critical functional role, patterned input-dependent inhibitory inputs may help maintain precise across populations output environmental odors, putatively sharpen enhancement tuning specificity individual odors.

Language: Английский

---

Olfactory deficits in aging and Alzheimer’s—spotlight on inhibitory interneurons

Frontiers in Neuroscience, Journal Year: 2024, Volume and Issue: 18

Published: Dec. 16, 2024

Cognitive function in healthy aging and neurodegenerative diseases like Alzheimer's disease (AD) correlates to olfactory performance. Aging progression both show marked deficits humans rodents. As a clear understanding of what causes is still missing, research on this topic paramount diagnostics early intervention therapy. A recent development focusing GABAergic interneurons. Both AD change excitation/inhibition balance, indicating reduced inhibitory network functions. In the system, inhibition has an especially prominent role processing information, as bulb (OB), first relay station information brain, contains unusually high number This review summarizes current knowledge interneurons at level OB primary cortices gain overview how these neurons might influence behavior. We also compare changes interneuron composition different brain areas between most common disease. find that pathophysiological mirror findings from hippocampal cortical regions describe cell loss for but not aging. Rather than differences areas, vulnerability were shown populations through all regions, with somatostatin-positive cells strongly affected.

Language: Английский

---