Facilitating Sensory Responses in Developing Mouse Somatosensory Barrel Cortex

2007 ◽  
Vol 97 (4) ◽  
pp. 2992-3003 ◽  
Author(s):  
Aren J. Borgdorff ◽  
James F. A. Poulet ◽  
Carl C. H. Petersen
Keyword(s):  
Barrel Cortex ◽  
Cortical Excitability ◽  
Sensory Response ◽  
Cortical Circuits ◽  
Pharmacological Agents ◽  
Sensory Stimuli ◽  
Early Postnatal Development ◽  
Sensory Responses ◽  
Activity Dependent ◽  
Whole Cell Recordings

The sensory responses in the barrel cortex of mice aged postnatal day (P)7–P12 evoked by a single whisker deflection are smaller in amplitude and spread over a smaller area than those measured in P13–P21 mice. However, repetitive 10-Hz stimulation or paired pulse whisker stimulation in P7–P12 mice evoked facilitating sensory responses, contrasting with the depressing sensory responses observed in P13–P21 mice. This facilitation occurred during an interval ranging 300–1,000 ms after the first stimulus and was measured using whole cell recordings, voltage-sensitive dye imaging, and calcium-sensitive dye imaging. The facilitated responses were not only larger in amplitude but also propagated over a larger cortical area. The facilitation could be blocked by local application of pharmacological agents reducing cortical excitability. Local cortical microstimulation could substitute for the first whisker stimulus to produce a facilitated sensory response. The enhanced sensory responses evoked by repetitive sensory stimuli in P7–P12 mice may contribute to the activity-dependent specification of the developing cortical circuits. In addition, the facilitating sensory responses allow long integration times for sensory processing compatible with the slow behavior of mice during early postnatal development.

Longitudinal imaging of VIP interneurons reveals sup-population specific effects of stroke that can be rescued with chemogenetic therapy

2021 ◽  
Author(s):  
Mohamad Motaharinia ◽  
Kimberly Gerrow ◽  
Roobina Boghozian ◽  
Emily White ◽  
Sun-Eui Choi ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Cortical Excitability ◽  
Sensory Response ◽  
Inhibitory Interneurons ◽  
Partial Recovery ◽  
Highly Active ◽  
Specific Effects ◽  
Somatosensory Responses ◽  
Sensory Responses ◽  
Longitudinal Imaging

Abstract Stroke profoundly disrupts cortical excitability which impedes recovery, but how it affects the function of specific inhibitory interneurons, or subpopulations therein, is poorly understood. Interneurons expressing vasoactive intestinal peptide (VIP) represent an intriguing stroke target because they can regulate cortical excitability through disinhibition. Here we chemogenetically augmented VIP interneuron excitability after stroke to show that it enhances somatosensory responses and improves recovery of paw function. Using longitudinal calcium imaging, we discovered that stroke primarily disrupts the fidelity (fraction of responsive trials) and predictability of sensory responses within a subset of highly active VIP neurons. Partial recovery of responses occurred largely within these active neurons and was not accompanied by the recruitment of minimally active neurons. Importantly, chemogenetic stimulation preserved sensory response fidelity and predictability in highly active neurons. These findings provide a new depth of understanding into how stroke and prospective therapies (chemogenetics), can influence subpopulations of inhibitory interneurons.

Chronic Suppression of Activity in Barrel Field Cortex Downregulates Sensory Responses in Contralateral Barrel Field Cortex

2005 ◽  
Vol 94 (5) ◽  
pp. 3342-3356 ◽  
Author(s):  
Lu Li ◽  
V. Rema ◽  
Ford F. Ebner
Keyword(s):  
Barrel Cortex ◽  
Cortical Excitability ◽  
Single Cells ◽  
Cortical Function ◽  
Adult Rats ◽  
Strong Suppression ◽  
Barrel Field ◽  
Layer V ◽  
Sensory Responses ◽  
Prominent Response

Numerous lines of evidence indicate that neural information is exchanged between the cerebral hemispheres via the corpus callosum. Unilateral ablation lesions of barrel field cortex (BFC) in adult rats induce strong suppression of background and evoked activity in the contralateral barrel cortex and significantly delay the onset of experience-dependent plasticity. The present experiments were designed to clarify the basis for these interhemispheric effects. One possibility is that degenerative events, triggered by the lesion, degrade contralateral cortical function. Another hypothesis, alone or in combination with degeneration, is that the absence of interhemispheric activity after the lesion suppresses contralateral responsiveness. The latter hypothesis was tested by placing an Alzet minipump subcutaneously and connecting it via a delivery tube to a cannula implanted over BFC. The minipump released muscimol, a GABAA receptor agonist at a rate of 1 μl/h, onto one barrel field cortex for 7 days. Then with the pump still in place, single cells were recorded in the contralateral BFC under urethan anesthesia. The data show a ∼50% reduction in principal whisker responses (D2) compared with controls, with similar reductions in responses to the D1 and D3 surround whiskers. Despite these reductions, spontaneous firing is unaffected. Fast spiking units are more sensitive to muscimol application than regular spiking units in both the response magnitude and the center/surround ratio. Effects of muscimol are also layer specific. Layer II/III and layer IV neurons decrease their responses significantly, unlike layer V neurons that fail to show significant deficits. The results indicate that reduced activity in one hemisphere alters cortical excitability in the other hemisphere in a complex manner. Surprisingly, a prominent response decrement occurs in the short-latency (3–10 ms) component of principal whisker responses, suggesting that suppression may spread to neurons dominated by thalamocortical inputs after interhemispheric connections are inactivated. Bilateral neurological impairments have been described after unilateral stroke lesions in the clinical literature.

scholarly journals Influence of Subcortical Inhibition on Barrel Cortex Receptive Fields

2009 ◽  
Vol 102 (1) ◽  
pp. 437-450 ◽  
Author(s):  
Akio Hirata ◽  
Juan Aguilar ◽  
Manuel A. Castro-Alamancos
Keyword(s):  
Receptive Field ◽  
High Frequency ◽  
Gaba Receptor ◽  
Barrel Cortex ◽  
Receptive Fields ◽  
Neural Responses ◽  
Sensory Stimuli ◽  
Long Latency ◽  
Actual Degree ◽  
Sensory Responses

Influence of subcortical inhibition on barrel cortex receptive fields. By the time neural responses driven by vibrissa stimuli reach the barrel cortex, they have undergone significant spatial and temporal transformations within subcortical relays. A major regulator of these transformations is thought to be subcortical GABA-mediated inhibition, but the actual degree of this influence is unknown. We used disinhibition produced by GABA receptor antagonists to unmask the excitatory sensory responses that are normally suppressed by inhibition in the main subcortical sensory relays to barrel cortex; principal trigeminal (Pr5) and primary thalamic (VPM) nuclei. We found that, within subcortical relays, inhibition only slightly suppresses short-latency receptive field responses, but robustly suppresses long-latency center and surround receptive field responses. However, the long-latency subcortical effects of inhibition are mostly not reflected in the barrel cortex. The most robust effect of subcortical inhibition on barrel cortex responses is to transiently suppress the receptive field responses of high-frequency sensory stimuli. This transient adaptation caused by subcortical inhibition recovers within a few stimuli and gives way to a steady-state adaptation that is independent of subcortical inhibition.

scholarly journals Longitudinal functional imaging of VIP interneurons reveals sup-population specific effects of stroke that are rescued with chemogenetic therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mohamad Motaharinia ◽  
Kim Gerrow ◽  
Roobina Boghozian ◽  
Emily White ◽  
Sun-Eui Choi ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Cortical Excitability ◽  
Sensory Response ◽  
Inhibitory Interneurons ◽  
Partial Recovery ◽  
Highly Active ◽  
Specific Effects ◽  
Somatosensory Responses ◽  
Photothrombotic Stroke ◽  
Sensory Responses

AbstractStroke profoundly disrupts cortical excitability which impedes recovery, but how it affects the function of specific inhibitory interneurons, or subpopulations therein, is poorly understood. Interneurons expressing vasoactive intestinal peptide (VIP) represent an intriguing stroke target because they can regulate cortical excitability through disinhibition. Here we chemogenetically augmented VIP interneuron excitability in a murine model of photothrombotic stroke and show that it enhances somatosensory responses and improves recovery of paw function. Using longitudinal calcium imaging, we discovered that stroke primarily disrupts the fidelity (fraction of responsive trials) and predictability of sensory responses within a subset of highly active VIP neurons. Partial recovery of responses occurred largely within these active neurons and was not accompanied by the recruitment of minimally active neurons. Importantly, chemogenetic stimulation preserved sensory response fidelity and predictability in highly active neurons. These findings provide a new depth of understanding into how stroke and prospective therapies (chemogenetics), can influence subpopulations of inhibitory interneurons.

FosGFP expression does not capture a sensory learning-related engram in superficial layers of mouse barrel cortex

2021 ◽  
Vol 118 (52) ◽  
pp. e2112212118
Author(s):  
Jiseok Lee ◽  
Joanna Urban-Ciecko ◽  
Eunsol Park ◽  
Mo Zhu ◽  
Stephanie E. Myal ◽  
...  
Keyword(s):  
Pyramidal Neurons ◽  
Barrel Cortex ◽  
Sensory Information ◽  
Learning Task ◽  
Early Gene ◽  
Sensory Stimuli ◽  
Association Learning ◽  
Neural Ensembles ◽  
Dependent Learning

Immediate-early gene (IEG) expression has been used to identify small neural ensembles linked to a particular experience, based on the principle that a selective subset of activated neurons will encode specific memories or behavioral responses. The majority of these studies have focused on “engrams” in higher-order brain areas where more abstract or convergent sensory information is represented, such as the hippocampus, prefrontal cortex, or amygdala. In primary sensory cortex, IEG expression can label neurons that are responsive to specific sensory stimuli, but experience-dependent shaping of neural ensembles marked by IEG expression has not been demonstrated. Here, we use a fosGFP transgenic mouse to longitudinally monitor in vivo expression of the activity-dependent gene c-fos in superficial layers (L2/3) of primary somatosensory cortex (S1) during a whisker-dependent learning task. We find that sensory association training does not detectably alter fosGFP expression in L2/3 neurons. Although training broadly enhances thalamocortical synaptic strength in pyramidal neurons, we find that synapses onto fosGFP+ neurons are not selectively increased by training; rather, synaptic strengthening is concentrated in fosGFP− neurons. Taken together, these data indicate that expression of the IEG reporter fosGFP does not facilitate identification of a learning-specific engram in L2/3 in barrel cortex during whisker-dependent sensory association learning.

scholarly journals Multisensory Integration in the Superior Colliculus of the Alert Cat

1998 ◽  
Vol 80 (2) ◽  
pp. 1006-1010 ◽  
Author(s):  
Mark T. Wallace ◽  
M. Alex Meredith ◽  
Barry E. Stein
Keyword(s):  
Superior Colliculus ◽  
Multisensory Integration ◽  
Sensory Response ◽  
Functional Link ◽  
Sensory Stimuli ◽  
Response Properties ◽  
Alert Cat

Wallace, Mark T., M. Alex Meredith, and Barry E. Stein. Multisensory integration in the superior colliculus of the alert cat. J. Neurophysiol. 80: 1006–1010, 1998. The modality convergence patterns, sensory response properties, and principles governing multisensory integration in the superior colliculus (SC) of the alert cat were found to have fundamental similarities to those in anesthetized animals. Of particular interest was the observation that, in a manner indistinguishable from the anesthetized animal, combinations of two different sensory stimuli significantly enhanced the responses of SC neurons above those evoked by either unimodal stimulus. These observations are consistent with the speculation that there is a functional link among multisensory integration in individual SC neurons and cross-modality attentive and orientation behaviors.

scholarly journals Hebbian activity-dependent plasticity in white matter

2022 ◽  
Author(s):  
Alberto Lazari ◽  
Piergiorgio Salvan ◽  
Michiel Cottaar ◽  
Daniel Papp ◽  
Matthew FS Rushworth ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
White Matter ◽  
Associative Learning ◽  
Fiber Bundle ◽  
Cortical Excitability ◽  
Brain Plasticity ◽  
Cortical Areas ◽  
Hebbian Plasticity ◽  
Synaptic Changes ◽  
Activity Dependent

Synaptic plasticity is required for learning and follows Hebb's Rule, the computational principle underpinning associative learning. In recent years, a complementary type of brain plasticity has been identified in myelinated axons, which make up the majority of brain's white matter. Like synaptic plasticity, myelin plasticity is required for learning, but it is unclear whether it is Hebbian or whether it follows different rules. Here, we provide evidence that white matter plasticity operates following Hebb's Rule in humans. Across two experiments, we find that co-stimulating cortical areas to induce Hebbian plasticity leads to relative increases in cortical excitability and associated increases in a myelin marker within the stimulated fiber bundle. We conclude that Hebbian plasticity extends beyond synaptic changes, and can be observed in human white matter fibers.

scholarly journals Functional selectivity and specific connectivity of inhibitory neurons in primary visual cortex

2018 ◽  
Author(s):  
Petr Znamenskiy ◽  
Mean-Hwan Kim ◽  
Dylan R. Muir ◽  
Maria Florencia Iacaruso ◽  
Sonja B. Hofer ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Pyramidal Cells ◽  
Fine Tuning ◽  
Inhibitory Neurons ◽  
Local Network ◽  
Cortical Circuits ◽  
Sensory Stimuli ◽  
Excitatory Neurons ◽  
Strong Excitation

In the cerebral cortex, the interaction of excitatory and inhibitory synaptic inputs shapes the responses of neurons to sensory stimuli, stabilizes network dynamics1 and improves the efficiency and robustness of the neural code2–4. Excitatory neurons receive inhibitory inputs that track excitation5–8. However, how this co-tuning of excitation and inhibition is achieved by cortical circuits is unclear, since inhibitory interneurons are thought to pool the inputs of nearby excitatory cells and provide them with non-specific inhibition proportional to the activity of the local network9–13. Here we show that although parvalbumin-expressing (PV) inhibitory cells in mouse primary visual cortex make connections with the majority of nearby pyramidal cells, the strength of their synaptic connections is structured according to the similarity of the cells’ responses. Individual PV cells strongly inhibit those pyramidal cells that provide them with strong excitation and share their visual selectivity. This fine-tuning of synaptic weights supports co-tuning of inhibitory and excitatory inputs onto individual pyramidal cells despite dense connectivity between inhibitory and excitatory neurons. Our results indicate that individual PV cells are preferentially integrated into subnetworks of inter-connected, co-tuned pyramidal cells, stabilising their recurrent dynamics. Conversely, weak but dense inhibitory connectivity between subnetworks is sufficient to support competition between them, de-correlating their output. We suggest that the history and structure of correlated firing adjusts the weights of both inhibitory and excitatory connections, supporting stable amplification and selective recruitment of cortical subnetworks.

Mechanosensory properties in the human gastric antrum evaluated using B-mode ultrasonography during volume-controlled antral distension

2006 ◽  
Vol 290 (5) ◽  
pp. G876-G882 ◽  
Author(s):  
H. Gregersen ◽  
T. Hausken ◽  
J. Yang ◽  
S. Ødegaard ◽  
O. H. Gilja
Keyword(s):  
Anticholinergic Drug ◽  
Muscle Length ◽  
Gastric Antrum ◽  
Variation Coefficient ◽  
Sensory Response ◽  
Pressure Amplitude ◽  
Sensory Responses ◽  
Volume Controlled ◽  
Antral Distension

The aims of this study were to evaluate gastric antral mechanical behavior and distension-induced sensorimotor responses in the human gastric antrum using transabdominal ultrasound scanning. Ten healthy volunteers underwent volume-controlled ramp inflation of a bag located in the antrum with volumes up to 125 ml. The active and passive circumferential tensions and stresses were calculated from measurements of pressure, diameter, and wall thickness before and during the administration of the anticholinergic drug butylscopolamine. The bag distensions elicited contractions in the antrum and sensory responses below the pain threshold. Butylscopolamine abolished the contractions and significantly reduced the sensory response. The length-tension diagram known from in vitro studies of smooth muscle strips could be reproduced as tension-volume diagrams in the human gastric antrum. The number of induced contractions and the contraction pressure amplitude (afterload) showed a parabolic behavior as function of the distension volume (preload), with maximum approximately at 70 ml. At the sensation threshold, the luminal circumference showed the lowest variation coefficient (13–25%), whereas the variation coefficient was more than 100% for the pressure, tensions, and stresses. We conclude that the muscle length-tension diagram and typical preload-afterload curves ad modem the Frank-Starling cardiac law can be obtained in the human gastric antrum. The sensory responses were most closely associated with the luminal circumference, indicating that the sensation during antral distension depends on deformation rather than on tension.

scholarly journals Reversibility of Multimodal Shift: Zebrafish Shift to Olfactory Cues When the Visual Environment Changes

2020 ◽  
Vol 60 (1) ◽  
pp. 33-42
Author(s):  
Piyumika S Suriyampola ◽  
Melissa Lopez ◽  
Brontë E Ellsworth ◽  
Emília P Martins
Keyword(s):  
Bright Light ◽  
Activity Level ◽  
Sensory Response ◽  
Opposite Pattern ◽  
Sensory Stimuli ◽  
Olfactory Responses ◽  
Lighting Conditions ◽  
Sensory Modalities ◽  
Complex Forms ◽  
Olfactory Cue

Synopsis Animals can shift their reliance on different sensory modalities in response to environmental conditions, and knowing the degree to which traits are reversible may help us to predict their chances of survival in a changing environment. Here, using adult zebrafish (Danio rerio), we found that 6 weeks in different light environments alone were sufficient to shift whether fish approached visual or chemical cues first, and that a subsequent reversal of lighting conditions also reversed their sensory preferences. In addition, we measured simple behavioral responses to sensory stimuli presented alone, and found that zebrafish housed in dim light for 6 weeks responded weakly to an optomotor assay, but strongly to an olfactory cue, whereas fish experiencing bright light for 6 weeks responded strongly to the visual optomotor stimulus and weakly in an olfactory assay. Visual and olfactory responses were equally reversible, and shifted to the opposite pattern when we reversed lighting conditions for 6 weeks. In contrast, we did not find a change in activity level, suggesting that changes in multiple sensory modalities can buffer animals from changes in more complex forms of behavior. This reversal of sensory response provides insight into how animals may use sensory shifts to keep up with environmental change.

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