scholarly journals Odor-evoked Increases in Spiking Variability in the Olfactory Bulb

2021 ◽  
Author(s):  
Cheng Ly ◽  
Andrea K. Barreiro ◽  
Shree Hari Gautam ◽  
Woodrow L. Shew
Keyword(s):  
Olfactory Bulb ◽  
General Principle ◽  
Sensory Stimulation ◽  
Sensory Systems ◽  
Stimulus Onset ◽  
Viable Alternative ◽  
Optogenetic Stimulation ◽  
Potential Benefits ◽  
Coding Strategy ◽  
Stimulation Of

AbstractAt the onset of sensory stimulation, the variability and co-variability of spiking activity is widely reported to decrease, especially in cortex. Considering the potential benefits of such decreased variability for coding, it has been suggested that this could be a general principle governing all sensory systems. Here we show that this is not so. We recorded neurons in olfactory bulb (OB) of anesthetized rats and found increased variability and co-variability of spiking at the onset of olfactory stimulation. Using models and analysis, we predicted that these increases arise due to network interactions within OB, without increasing variability of input from the nose. We tested and confirmed this prediction using optogenetic stimulation of OB in awake animals. Our results establish increases in spiking variability at stimulus onset as a viable alternative coding strategy to the more commonly observed decreases in variability in many cortical systems.

scholarly journals Incerto-thalamic modulation of fear via GABA and dopamine

2021 ◽  
Author(s):  
Archana Venkataraman ◽  
Sarah C. Hunter ◽  
Maria Dhinojwala ◽  
Diana Ghebrezadik ◽  
JiDong Guo ◽  
...  
Keyword(s):  
Brain Regions ◽  
Zona Incerta ◽  
Dependent Manner ◽  
Post Traumatic Stress ◽  
Functional Roles ◽  
Functional Connections ◽  
Optogenetic Stimulation ◽  
Fear Generalization ◽  
Stimulation Of

AbstractFear generalization and deficits in extinction learning are debilitating dimensions of Post-Traumatic Stress Disorder (PTSD). Most understanding of the neurobiology underlying these dimensions comes from studies of cortical and limbic brain regions. While thalamic and subthalamic regions have been implicated in modulating fear, the potential for incerto-thalamic pathways to suppress fear generalization and rescue deficits in extinction recall remains unexplored. We first used patch-clamp electrophysiology to examine functional connections between the subthalamic zona incerta and thalamic reuniens (RE). Optogenetic stimulation of GABAergic ZI → RE cell terminals in vitro induced inhibitory post-synaptic currents (IPSCs) in the RE. We then combined high-intensity discriminative auditory fear conditioning with cell-type-specific and projection-specific optogenetics in mice to assess functional roles of GABAergic ZI → RE cell projections in modulating fear generalization and extinction recall. In addition, we used a similar approach to test the possibility of fear generalization and extinction recall being modulated by a smaller subset of GABAergic ZI → RE cells, the A13 dopaminergic cell population. Optogenetic stimulation of GABAergic ZI → RE cell terminals attenuated fear generalization and enhanced extinction recall. In contrast, optogenetic stimulation of dopaminergic ZI → RE cell terminals had no effect on fear generalization but enhanced extinction recall in a dopamine receptor D1-dependent manner. Our findings shed new light on the neuroanatomy and neurochemistry of ZI-located cells that contribute to adaptive fear by increasing the precision and extinction of learned associations. In so doing, these data reveal novel neuroanatomical substrates that could be therapeutically targeted for treatment of PTSD.

scholarly journals Effect of Aging, Gender and Sensory Stimulation of TRPV1 Receptors with Capsaicin on Spontaneous Swallowing Frequency in Patients with Oropharyngeal Dysphagia: A Proof-of-Concept Study

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 461
Author(s):  
Weslania Nascimento ◽  
Noemí Tomsen ◽  
Saray Acedo ◽  
Cristina Campos-Alcantara ◽  
Christopher Cabib ◽  
...  
Keyword(s):  
Oropharyngeal Dysphagia ◽  
Sensory Stimulation ◽  
Age And Gender ◽  
Post Stroke ◽  
Brainstem Reflex ◽  
Trpv1 Receptors ◽  
Volume Viscosity ◽  
And Gender ◽  
Effect Of Age ◽  
Stimulation Of

Spontaneous swallowing contributes to airway protection and depends on the activation of brainstem reflex circuits in the central pattern generator (CPG). We studied the effect of age and gender on spontaneous swallowing frequency (SSF) in healthy volunteers and assessed basal SSF and TRPV1 stimulation effect on SSF in patients with post-stroke oropharyngeal dysphagia (OD). The effect of age and gender on SSF was examined on 141 healthy adult volunteers (HV) divided into three groups: GI—18–39 yr, GII—40–59 yr, and GIII—>60 yr. OD was assessed by the Volume–Viscosity Swallowing Test (VVST). The effect of sensory stimulation with capsaicin 10−5 M (TRPV1 agonist) was evaluated in 17 patients with post-stroke OD, using the SSF. SSF was recorded in all participants during 10 min using surface electromyography (sEMG) of the suprahyoid muscles and an omnidirectional accelerometer placed over the cricothyroid cartilage. SSF was significantly reduced in GII (0.73 ± 0.50 swallows/min; p = 0.0385) and GIII (0.50 ± 0.31 swallows/min; p < 0.0001) compared to GI (1.03 ± 0.62 swallows/min), and there was a moderate significant correlation between age and SFF (r = −0.3810; p < 0.0001). No effect of gender on SSF was observed. Capsaicin caused a strong and significant increase in SSF after the TRPV1 stimulation when comparing to basal condition (pre-capsaicin: 0.41 ± 0.32 swallows/min vs post-capsaicin: 0.81 ± 0.51 swallow/min; p = 0.0003). OD in patients with post-stroke OD and acute stimulation with TRPV1 agonists caused a significant increase in SSF, further suggesting the potential role of pharmacological stimulation of sensory pathways as a therapeutic strategy for CPG activation in patients with OD.

scholarly journals Involvement of MCH-oxytocin neural relay within the hypothalamus in murine nursing behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoko Kato ◽  
Harumi Katsumata ◽  
Ayumu Inutsuka ◽  
Akihiro Yamanaka ◽  
Tatsushi Onaka ◽  
...  
Keyword(s):  
Mammalian Species ◽  
Virgin Female ◽  
Essential Elements ◽  
Hypothalamic Nucleus ◽  
Male Mice ◽  
Hypothalamic Area ◽  
Functional Roles ◽  
Genetic Ablation ◽  
Optogenetic Stimulation ◽  
Stimulation Of

AbstractMultiple sequential actions, performed during parental behaviors, are essential elements of reproduction in mammalian species. We showed that neurons expressing melanin concentrating hormone (MCH) in the lateral hypothalamic area (LHA) are more active in rodents of both sexes when exhibiting parental nursing behavior. Genetic ablation of the LHA-MCH neurons impaired maternal nursing. The post-birth survival rate was lower in pups born to female mice with congenitally ablated MCH neurons under control of tet-off system, exhibiting reduced crouching behavior. Virgin female and male mice with ablated MCH neurons were less interested in pups and maternal care. Chemogenetic and optogenetic stimulation of LHA-MCH neurons induced parental nursing in virgin female and male mice. LHA-MCH GABAergic neurons project fibres to the paraventricular hypothalamic nucleus (PVN) neurons. Optogenetic stimulation of PVN induces nursing crouching behavior along with increasing plasma oxytocin levels. The hypothalamic MCH neural relays play important functional roles in parental nursing behavior in female and male mice.

Suckling pheromone stimulation of a modified glomerular region in the developing rat olfactory bulb revealed by the 2-deoxyglucose method

1980 ◽  
Vol 194 (2) ◽  
pp. 530-535 ◽  
Author(s):  
Martin H. Teicher ◽  
William B. Stewart ◽  
John S. Kauer ◽  
Gordon M. Shepherd
Keyword(s):  
Olfactory Bulb ◽  
Developing Rat ◽  
Deoxyglucose Method ◽  
Stimulation Of

scholarly journals Characterizing pinprick-evoked brain potentials before and after experimentally induced secondary hyperalgesia

2015 ◽  
Vol 114 (5) ◽  
pp. 2672-2681 ◽  
Author(s):  
Emanuel N. van den Broeke ◽  
André Mouraux ◽  
Antonia H. Groneberg ◽  
Doreen B. Pfau ◽  
Rolf-Detlef Treede ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Stimulus Onset ◽  
Secondary Hyperalgesia ◽  
Brain Potentials ◽  
Nociceptive Pathways ◽  
Before And After ◽  
Pain Ratings ◽  
Related Potentials ◽  
Positive Complex ◽  
Stimulation Of

Secondary hyperalgesia is believed to be a key feature of “central sensitization” and is characterized by enhanced pain to mechanical nociceptive stimuli. The aim of the present study was to characterize, using EEG, the effects of pinprick stimulation intensity on the magnitude of pinprick-elicited brain potentials [event-related potentials (ERPs)] before and after secondary hyperalgesia induced by intradermal capsaicin in humans. Pinprick-elicited ERPs and pinprick-evoked pain ratings were recorded in 19 healthy volunteers, with mechanical pinprick stimuli of varying intensities (0.25-mm probe applied with a force extending between 16 and 512 mN). The recordings were performed before (T0) and 30 min after (T1) intradermal capsaicin injection. The contralateral noninjected arm served as control. ERPs elicited by stimulation of untreated skin were characterized by 1) an early-latency negative-positive complex peaking between 120 and 250 ms after stimulus onset (N120-P240) and maximal at the vertex and 2) a long-lasting positive wave peaking 400–600 ms after stimulus onset and maximal more posterior (P500), which was correlated to perceived pinprick pain. After capsaicin injection, pinprick stimuli were perceived as more intense in the area of secondary hyperalgesia and this effect was stronger for lower compared with higher stimulus intensities. In addition, there was an enhancement of the P500 elicited by stimuli of intermediate intensity, which was significant for 64 mN. The other components of the ERPs were unaffected by capsaicin. Our results suggest that the increase in P500 magnitude after capsaicin is mediated by facilitated mechanical nociceptive pathways.

Direct optogenetic stimulation of smooth muscle cells to control gastric contractility

2021 ◽  
Author(s):  
R Patejdl ◽  
M Vogt ◽  
B Schulz ◽  
A Wagdi ◽  
J Lebert ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Optogenetic Stimulation ◽  
Stimulation Of

Striatal dopamine mediates hallucination-like perception in mice

Science ◽  
2021 ◽  
Vol 372 (6537) ◽  
pp. eabf4740
Author(s):  
K. Schmack ◽  
M. Bosc ◽  
T. Ott ◽  
J. F. Sturgill ◽  
A. Kepecs
Keyword(s):  
Psychotic Disorders ◽  
Neural Circuit ◽  
Dopamine Neurons ◽  
Striatal Dopamine ◽  
Model Organisms ◽  
High Confidence ◽  
Optogenetic Stimulation ◽  
The Brain ◽  
Central Symptom ◽  
Stimulation Of

Hallucinations, a central symptom of psychotic disorders, are attributed to excessive dopamine in the brain. However, the neural circuit mechanisms by which dopamine produces hallucinations remain elusive, largely because hallucinations have been challenging to study in model organisms. We developed a task to quantify hallucination-like perception in mice. Hallucination-like percepts, defined as high-confidence false detections, increased after hallucination-related manipulations in mice and correlated with self-reported hallucinations in humans. Hallucination-like percepts were preceded by elevated striatal dopamine levels, could be induced by optogenetic stimulation of mesostriatal dopamine neurons, and could be reversed by the antipsychotic drug haloperidol. These findings reveal a causal role for dopamine-dependent striatal circuits in hallucination-like perception and open new avenues to develop circuit-based treatments for psychotic disorders.

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