scholarly journals Differential impacts of repeated sampling on odor representations by genetically-defined mitral and tufted cell subpopulations in the mouse olfactory bulb

2020 ◽  
Author(s):  
Thomas P. Eiting ◽  
Matt Wachowiak
Keyword(s):  
Information Processing ◽  
Olfactory Bulb ◽  
High Frequency ◽  
Response Patterns ◽  
Repeated Sampling ◽  
Tufted Cell ◽  
Cell Subpopulations ◽  
Genetic Targeting ◽  
The Impact ◽  
Over Time

AbstractSniffing—the active control of breathing beyond passive respiration—is used by mammals to modulate olfactory sampling. Sniffing allows animals to make odor-guided decisions within ~200 ms, but animals routinely engage in bouts of high-frequency sniffing spanning several seconds; the impact of such repeated odorant sampling on odor representations remains unclear. We investigated this question in the mouse olfactory bulb, where mitral and tufted cells (MTCs) form parallel output streams of odor information processing. To test the impact of repeated odorant sampling on MTC responses, we used two-photon imaging in anesthetized male and female mice to record activation of MTCs while precisely varying inhalation frequency. A combination of genetic targeting and viral expression of GCaMP6 reporters allowed us to access mitral (MC) and superficial tufted cell (sTC) subpopulations separately. We found that repeated odorant sampling differentially affected responses in MCs and sTCs, with MCs showing more diversity than sTCs over the same time period. Impacts of repeated sampling among MCs included both increases and decreases in excitation, as well as changes in response polarity. Response patterns across ensembles of simultaneously-imaged MCs reformatted over time, with representations of different odorants becoming more distinct. MCs also responded differentially to changes in inhalation frequency, whereas sTC responses were more uniform over time and across frequency. Our results support the idea that MCs and TCs comprise functionally distinct pathways for odor information processing, and suggest that the reformatting of MC odor representations by high-frequency sniffing may serve to enhance the discrimination of similar odors.

scholarly journals Temporal dynamics of inhalation-linked activity across defined subpopulations of mouse olfactory bulb neurons imaged in vivo

2019 ◽  
Author(s):  
Shaina M. Short ◽  
Matt Wachowiak
Keyword(s):  
Olfactory Bulb ◽  
Temporal Dynamics ◽  
Cell Types ◽  
Response Patterns ◽  
Two Photon ◽  
Cell Type Specific ◽  
Olfactory Processing ◽  
Tufted Cells ◽  
Cell Subpopulations

ABSTRACTIn mammalian olfaction, inhalation drives the temporal patterning of neural activity that underlies early olfactory processing, and a single inhalation of odorant is sufficient for odor perception. However, how the neural circuits that process incoming olfactory information are activated in the context of inhalation-linked dynamics remains poorly understood. To better understand early olfactory processing in vivo, we used an artificial inhalation paradigm combined with two-photon calcium imaging to compare the dynamics of activity evoked by odorant inhalation across major cell types of the mouse olfactory bulb. Transgenic models and cell-type specific genetic tools were used to express GCaMP6f or jRGECO1a in mitral and tufted cell subpopulations, olfactory sensory neurons and two major juxtaglomerular interneuron classes, and responses to a single inhalation of odorant were compared. Activity in all cell types was strongly linked to inhalation, and all cell types showed some variance in the latency, rise-times and durations of their inhalation-linked response patterns. The dynamics of juxtaglomerular interneuron activity closely matched that of sensory neuron inputs, while mitral and tufted cells showed the highest diversity in dynamics, with a range of latencies and durations that could not be accounted for by heterogeneity in the dynamics of sensory input. Surprisingly, temporal response patterns of mitral and superficial tufted cells were highly overlapping such that these two subpopulations could not be distinguished on the basis of their inhalation-linked dynamics, with the exception of a subpopulation of superficial tufted cells expressing the peptide transmitter cholecystokinin. Overall, these results support a model in which diversity in inhalation-linked patterning of OB output arises first at the level of OSN inputs to the OB and is enhanced by feedforward inhibition from juxtaglomerular interneurons which differentially impacts different subpopulations of OB output neurons.

The Contagious Effect of Deviant Behavior in Adolescence

2017 ◽  
Vol 9 (7) ◽  
pp. 815-824 ◽  
Author(s):  
Robert Busching ◽  
Barbara Krahé
Keyword(s):  
Information Processing ◽  
Social Information Processing ◽  
Deviant Behavior ◽  
Peer Group ◽  
Peer Groups ◽  
The Social ◽  
Main Effect ◽  
Self Reports ◽  
The Impact ◽  
Over Time

This article investigated how the development of deviant behavior in adolescence is influenced by the variability of deviant behavior in the peer group. Based on the social information-processing (SIP) model, we predicted that peer groups with a low variability of deviant behavior (providing normative information that is easy to process) should have a main effect on the development of adolescents’ deviant behavior over time, whereas peer groups in which deviant behavior is more variable (i.e., more difficult to process) should primarily impact the deviant behavior of initially nondeviant classroom members. These hypotheses were largely supported in a multilevel analysis using self-reports of deviant behavior in a sample of 16,891 adolescents in 1,308 classes assessed at two data waves about 1-year apart. The results demonstrate the advantages of studying cross-level interactions to clarify the impact of the peer environment on the development of deviant behavior in adolescence.

scholarly journals Heterogeneous effects of norepinephrine on spontaneous and stimulus-driven activity in the male accessory olfactory bulb

2017 ◽  
Vol 117 (3) ◽  
pp. 1342-1351 ◽  
Author(s):  
Wayne I. Doyle ◽  
Julian P. Meeks
Keyword(s):  
Information Processing ◽  
Olfactory Bulb ◽  
Spontaneous Activity ◽  
Behavioral Plasticity ◽  
Ex Vivo ◽  
Model Systems ◽  
Projection Neurons ◽  
Response Suppression ◽  
Accessory Olfactory Bulb ◽  
The Impact

Norepinephrine (NE) release has been linked to experience-dependent plasticity in many model systems and brain regions. Among these is the rodent accessory olfactory system (AOS), which is crucial for detecting and processing socially relevant environmental cues. The accessory olfactory bulb (AOB), the first site of chemosensory information processing in the AOS, receives dense centrifugal innervation by noradrenergic fibers originating in the locus coeruleus. Although NE release has been linked to behavioral plasticity through its actions in the AOB, the impacts of noradrenergic modulation on AOB information processing have not been thoroughly studied. We made extracellular single-unit recordings of AOB principal neurons in ex vivo preparations of the early AOS taken from adult male mice. We analyzed the impacts of bath-applied NE (10 μM) on spontaneous and stimulus-driven activity. In the presence of NE, we observed overall suppression of stimulus-driven neuronal activity with limited impact on spontaneous activity. NE-associated response suppression in the AOB came in two forms: one that was strong and immediate (21%) and one other that involved gradual, stimulus-dependent monotonic response suppression (47%). NE-associated changes in spontaneous activity were more modest, with an overall increase in spontaneous spike frequency observed in 25% of neurons. Neurons with increased spontaneous activity demonstrated a net decrease in chemosensory discriminability. These results reveal that noradrenergic signaling in the AOB causes cell-specific changes in chemosensory tuning, even among similar projection neurons. NEW & NOTEWORTHY Norepinephrine (NE) is released throughout the brain in many behavioral contexts, but its impacts on information processing are not well understood. We studied the impact of NE on chemosensory tuning in the mouse accessory olfactory bulb (AOB). Electrophysiological recordings from AOB neurons in ex vivo preparations revealed that NE, on balance, inhibited mitral cell responses to chemosensory cues. However, NE’s effects were heterogeneous, indicating that NE signaling reshapes AOB output in a cell- and stimulus-specific manner.

scholarly journals The impact of COVID-19 restrictions on older adults' loneliness: Evidence from high-frequency panel data

2021 ◽  
Author(s):  
Erwin Stolz ◽  
Hannes Mayerl ◽  
Wolfgang Freidl
Keyword(s):  
Older Adults ◽  
Panel Data ◽  
High Frequency ◽  
Regression Models ◽  
Repeated Observations ◽  
Mixed Regression ◽  
The Impact ◽  
Over Time

BACKGROUND: It is unclear how strong and long lasting the effects of recurring COVID-19 restrictions on older adults' loneliness are. METHODS: 469 retired older adults (60+) provided 8,814 repeated observations of loneliness (27 waves) in the Austrian Corona Panel Project between March 2020 and December 2021. Ordinal mixed regression models were used to estimate the effect of the stringency of COVID-19 restrictions (SI) on loneliness. RESULTS: The proportion of older adults who reported to be often lonely correlated closely (r=0.63) with the SI over time: both peaked during lockdowns (SI=82, often lonely=10-12%) and were lowest during the summer of 2020 (SI=36, often lonely=5- 6%). Results from regression models indicate, that when the SI increased above 60 (=strict lockdown), an increase in loneliness followed. Older adults who lived alone were more affected than those living with others. CONCLUSIONS: Stringent COVID-19 restrictions lead to situational loneliness, par- ticularly among those who lived alone. Efforts should be made to enable older adults who live alone to have save in-person contact during lockdown periods.

A metatheoretical framework of diversity in teams

2016 ◽  
Vol 70 (8) ◽  
pp. 911-939 ◽  
Author(s):  
Margarita Mayo ◽  
Maria Kakarika ◽  
Charalampos Mainemelis ◽  
Nicolas Till Deuschel
Keyword(s):  
Information Processing ◽  
Theoretical Models ◽  
Social Categorization ◽  
Response Patterns ◽  
Dynamic Nature ◽  
Team Diversity ◽  
Team Success ◽  
Group Boundary ◽  
Over Time ◽  
The Way

In the last 22 years, research on diversity in teams has been propelled by information processing and social categorization theories, and more recently, by theories of disparity/(in)justice and access to external networks. These theories stress different diversity processes, treating team diversity respectively as variety of information, as separation, as disparity, and as variety of access. We appraise this literature by identifying major problems in the way these four foundational theories are used either alone or in combination, arguing that the related theoretical models are inherently incomplete and static. In an attempt to resolve these problems, we introduce a metatheoretical framework that relates these four foundational theories according to the metadimensions of group boundary and diversity mindset. We also propose a metatheoretical model that identifies interactions among the four diversity processes and specifies diversity response patterns to team success or failure over time. Our metatheoretical approach resolves significant omissions in the literature and penetrates into the dynamic nature of team diversity in more complex, temporally sensitive and synthetic ways.

Spatial patterns of olfactory bulb single-unit responses to learned olfactory cues in young rats

1988 ◽  
Vol 59 (6) ◽  
pp. 1770-1782 ◽  
Author(s):  
D. A. Wilson ◽  
M. Leon
Keyword(s):  
Olfactory Bulb ◽  
Single Unit ◽  
Response Pattern ◽  
Neonatal Rat ◽  
Odor Stimulus ◽  
Focal Region ◽  
Response Patterns ◽  
Training Groups ◽  
Tufted Cells ◽  
Tufted Cell

1. Neonatal rat pups were classically conditioned to an odor stimulus from postnatal day 1 (PN1) to PN18. Tactile stimulation (stroking) was used as the unconditioned stimulus. On PN19, mitral/tufted cell single-unit responses to the conditioned odor were examined in both conditioned and control pups. Recordings were made from mitral/tufted cells in two regions of the olfactory bulb: 1) an area typically associated with focal [14C]2-deoxyglucose (2-DG) uptake in response to the conditioned odor and 2) an area distant from focal 2-DG uptake to the conditioned odor. Animals were anesthetized with urethane and were naturally respiring during the single-unit recording procedure. 2. Changes in mitral/tufted cell firing rate in response to odors in both bulbar regions and all training groups were classified as either excitatory, suppressive, or no response. This response classification was used to compare response patterns to the conditioned odor between bulbar regions and training groups. 3. Classical conditioning selectively modified the response patterns of mitral/tufted cells to the conditioned odor when those cells were associated with regions of focal 2-DG uptake for that odor. Mitral/tufted cells demonstrated significantly more suppressive and fewer excitatory responses to the conditioned odor than cells in control pups. Response patterns to a novel odor were not similarly modified. 4. Response patterns of mitral/tufted cells distant from the focal region of 2-DG uptake to the conditioned odor were not modified by conditioning compared with control pups. 5. The difference in response pattern between cells in the 2-DG focus and cells distant to the 2-DG focus was apparent within 500 ms of the stimulus onset. Given the respiratory rate of these pups (2 Hz), these data suggest that the modified response pattern occurred on the first inhalation of the learned odor. 6. These data demonstrate that both spatial and temporal patterns of olfactory bulb output neuron activity are used in the coding of olfactory information in the bulb. Furthermore, these spatial/temporal response patterns can be modified by early learning.

scholarly journals Inhalation frequency controls reformatting of mitral/tufted cell odor representations in the olfactory bulb

2018 ◽  
Author(s):  
Marta Díaz-Quesada ◽  
Isaac A. Youngstrom ◽  
Yusuke Tsuno ◽  
Kyle R. Hansen ◽  
Michael N. Economo ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Neural Coding ◽  
Low Frequency ◽  
Sampling Frequency ◽  
Projection Neurons ◽  
Olfactory Sensation ◽  
Sampling Behavior ◽  
Olfactory Stimuli ◽  
Repeated Sampling ◽  
The Impact

AbstractIn mammals olfactory sensation depends on inhalation, which controls activation of sensory neurons and temporal patterning of central activity. Odor representations by mitral and tufted (MT) cells, the main output from the olfactory bulb (OB), reflect sensory input as well as excitation and inhibition from OB circuits, which may change as sniff frequency increases. To test the impact of sampling frequency on MT cell odor responses, we obtained whole-cell recordings from MT cells in anesthetized male and female mice while varying inhalation frequency via tracheotomy, allowing comparison of inhalation-linked responses across cells. We characterized frequency effects on MT cell responses during inhalation of air and odorants using inhalation pulses and also ‘playback’ of sniffing recorded from awake mice. Inhalation-linked changes in membrane potential were well-predicted across frequency from linear convolution of 1 Hz responses and, as frequency increased, near-identical temporal responses could emerge from depolarizing, hyperpolarizing or multiphasic MT responses. However, net excitation was not well predicted from 1 Hz responses and varied substantially across MT cells, with some cells increasing and others decreasing in spike rate. As a result, sustained odorant sampling at higher frequencies led to increasing decorrelation of the MT cell population response pattern over time. Bulk activation of sensory inputs by optogenetic stimulation affected MT cells more uniformly across frequency, suggesting that frequency-dependent decorrelation emerges from odor-specific patterns of activity in the OB network. These results suggest that sampling behavior alone can reformat early sensory representations, possibly to optimize sensory perception during repeated sampling.Significance statementOlfactory sensation in mammals depends on inhalation, which increases in frequency during active sampling of olfactory stimuli. We asked how inhalation frequency can shape the neural coding of odor information by recording from projection neurons of the olfactory bulb while artificially varying odor sampling frequency in the anesthetized mouse. We found that sampling an odor at higher frequencies led to diverse changes in net responsiveness, as measured by action potential output, that were not predicted from low-frequency responses. These changes led to a reorganization of the pattern of neural activity evoked by a given odorant that occurred preferentially during sustained, high-frequency inhalation. These results point to a novel mechanism for modulating early sensory representations solely as a function of sampling behavior.

The Therapist’s Reaction to a Patient’s Suicide

Crisis ◽  
2011 ◽  
Vol 32 (2) ◽  
pp. 99-105 ◽  
Author(s):  
Friedrich Martin Wurst ◽  
Isabella Kunz ◽  
Gregory Skipper ◽  
Manfred Wolfersdorf ◽  
Karl H. Beine ◽  
...  
Keyword(s):  
Emotional Responses ◽  
Well Being ◽  
Emotional Reaction ◽  
Emotional Reactions ◽  
Analog Scale ◽  
General Hospitals ◽  
Item Questionnaire ◽  
Retrospective Nature ◽  
The Impact ◽  
Over Time

Background: A substantial proportion of therapists experience the loss of a patient to suicide at some point during their professional life. Aims: To assess (1) the impact of a patient’s suicide on therapists distress and well-being over time, (2) which factors contribute to the reaction, and (3) which subgroup might need special interventions in the aftermath of suicide. Methods: A 63-item questionnaire was sent to all 185 Psychiatric Clinics at General Hospitals in Germany. The emotional reaction of therapists to patient’s suicide was measured immediately, after 2 weeks, and after 6 months. Results: Three out of ten therapists suffer from severe distress after a patients’ suicide. The item “overall distress” immediately after the suicide predicts emotional reactions and changes in behavior. The emotional responses immediately after the suicide explained 43.5% of the variance of total distress in a regression analysis. Limitations: The retrospective nature of the study is its primary limitation. Conclusions: Our data suggest that identifying the severely distressed subgroup could be done using a visual analog scale for overall distress. As a consequence, more specific and intensified help could be provided to these professionals.

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