scholarly journals Cellular precision of orientation and spatial frequency maps in macaque V1

2019 ◽  
Author(s):  
Nian-Sheng Ju ◽  
Shu-Chen Guan ◽  
Shi-Ming Tang ◽  
Cong Yu
Keyword(s):  
Spatial Frequency ◽  
Calcium Imaging ◽  
Functional Organization ◽  
Neuronal Response ◽  
Guiding Principle ◽  
Two Photon ◽  
Frequency Branch ◽  
Geometric Relationship ◽  
The Brain ◽  
Specific Orientation

AbstractFunctional organization of neuronal response properties along the surface of the neocortex is a fundamental guiding principle of neural computation in the brain. Despite this importance, the cellular precision of functional maps is still largely unknown. We address the challenge by using two-photon calcium imaging to measure cell-specific orientation and spatial frequency (SF) responses across fields of macaque V1 superficial layers. The cellular orientation maps confirm iso-orientation domains, but rarely show pinwheels. Pinwheels obtained through conventional Gaussian smoothing and vector summation of orientation responses mostly overlap with blood vessel regions, suggesting false singularities. Cellular SF maps clarify existing controversies by showing weak iso-frequency clusters, which also suggests a weak geometric relationship between orientation and SF maps. Most neurons are tuned to medium frequencies, but the tuning functions are often asymmetric with a wider low- or high-frequency branch, which may help encode low or high SF information for later decoding.

Functional organization of spatial frequency tuning in macaque V1 revealed with two-photon calcium imaging

2021 ◽  
pp. 102120
Author(s):  
Shu-Chen Guan ◽  
Nian-Sheng Ju ◽  
Louis Tao ◽  
Shi-Ming Tang ◽  
Cong Yu
Keyword(s):  
Spatial Frequency ◽  
Calcium Imaging ◽  
Functional Organization ◽  
Frequency Tuning ◽  
Two Photon ◽  
Spatial Frequency Tuning

scholarly journals Widespread inhibition, antagonism, and synergy in mouse olfactory sensory neurons in vivo

2019 ◽  
Author(s):  
Shigenori Inagaki ◽  
Ryo Iwata ◽  
Masakazu Iwamoto ◽  
Takeshi Imai
Keyword(s):  
Sensory Neurons ◽  
Calcium Imaging ◽  
Odorant Receptor ◽  
Sensory Information ◽  
Olfactory Sensory Neurons ◽  
Axon Terminals ◽  
Two Photon ◽  
Odor Mixtures ◽  
The Brain

SUMMARYSensory information is selectively or non-selectively inhibited and enhanced in the brain, but it remains unclear whether this occurs commonly at the peripheral stage. Here, we performed two-photon calcium imaging of mouse olfactory sensory neurons (OSNs) in vivo and found that odors produce not only excitatory but also inhibitory responses at their axon terminals. The inhibitory responses remained in mutant mice, in which all possible sources of presynaptic lateral inhibition were eliminated. Direct imaging of the olfactory epithelium revealed widespread inhibitory responses at OSN somata. The inhibition was in part due to inverse agonism toward the odorant receptor. We also found that responses to odor mixtures are often suppressed or enhanced in OSNs: Antagonism was dominant at higher odor concentrations, whereas synergy was more prominent at lower odor concentrations. Thus, odor responses are extensively tuned by inhibition, antagonism, and synergy, at the early peripheral stage, contributing to robust odor representations.

scholarly journals Multi-functional feedforward inhibitory circuits for cortical odor processing

2021 ◽  
Author(s):  
Norimitsu Suzuki ◽  
Malinda L. S. Tantirigama ◽  
Helena H.-Y. Huang ◽  
John M. Bekkers
Keyword(s):  
Calcium Imaging ◽  
Piriform Cortex ◽  
Complex Interplay ◽  
Inhibitory Circuits ◽  
Two Photon ◽  
Odor Processing ◽  
Strong Excitation ◽  
The Brain ◽  
Feedforward Inhibition

Feedforward inhibitory circuits are key contributors to the complex interplay between excitation and inhibition in the brain. Little is known about the function of feedforward inhibition in the primary olfactory (piriform) cortex. Using in vivo two-photon targeted patch clamping and calcium imaging in mice, we find that odors evoke strong excitation in two classes of interneurons – neurogliaform (NG) cells and horizontal (HZ) cells – that provide feedforward inhibition in layer 1 of the piriform cortex. NG cells fire much earlier than HZ cells following odor onset, a difference that can be attributed to the faster odor-driven excitatory synaptic drive that NG cells receive from the olfactory bulb. As a consequence, NG cells strongly but transiently inhibit odor-evoked excitation in layer 2 principal cells, whereas HZ cells provide more diffuse and prolonged feedforward inhibition. Our findings reveal unexpected complexity in the operation of inhibition in the piriform cortex.

scholarly journals Simultaneous mesoscopic and two-photon imaging of neuronal activity in cortical circuits

2018 ◽  
Author(s):  
D Barson ◽  
AS Hamodi ◽  
X Shen ◽  
G Lur ◽  
RT Constable ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Spatial Scales ◽  
Cortical Circuits ◽  
Orthogonal Axis ◽  
Two Photon ◽  
Evoked Activity ◽  
Sensory Evoked ◽  
Local Circuits ◽  
The Brain ◽  
Juvenile Mouse

AbstractSpontaneous and sensory-evoked activity propagates across spatial scales in the mammalian cortex but technical challenges have generally precluded establishing conceptual links between the function of local circuits of neurons and brain-wide network dynamics. To solve this problem, we developed a method for simultaneous cellular-resolution two-photon calcium imaging of a local microcircuit and mesoscopic widefield calcium imaging of the entire cortical mantle in awake, behaving mice. Our method employs an orthogonal axis design whereby the mesoscopic objective is oriented downward directly above the brain and the two-photon objective is oriented horizontally, with imaging performed through a glass right angle microprism implanted in the skull. In support of this method, we introduce a suite of analysis tools for relating the activity of individual cells to distal cortical areas, as well as a viral method for robust and widespread gene delivery in the juvenile mouse brain. We use these methods to characterize the diversity of associations of individual, genetically-defined neurons with cortex-wide network motifs.

scholarly journals Diverse operant control of different motor cortex populations during learning

2021 ◽  
Author(s):  
Nuria Vendrell-Llopis ◽  
Ching Fang ◽  
Albert J Qu ◽  
Rui M Costa ◽  
Jose M Carmena
Keyword(s):  
Motor Cortex ◽  
Calcium Imaging ◽  
Functional Organization ◽  
Pyramidal Tract ◽  
Neuron Activity ◽  
Machine Interface ◽  
Local Circuitry ◽  
To Receive ◽  
The Brain ◽  
Better Than

During motor learning, as well as during neuroprosthetic learning, animals learn to control motor cortex activity in order to generate behavior. Two different population of motor cortex neurons, intra-telencephalic (IT) and pyramidal tract (PT) neurons, convey the resulting cortical signals within and outside the telencephalon. Although a large amount of evidence demonstrates contrasting functional organization among both populations, it is unclear whether the brain can equally learn to control the activity of either class of motor cortex neurons. To answer this question, we used a Calcium imaging based brain-machine interface (CaBMI) and trained different groups of mice to modulate the activity of either IT or PT neurons in order to receive a reward. We found that animals learn to control PT neuron activity faster and better than IT neuron activity. Moreover, our findings show that the advantage of PT neurons is the result of characteristics inherent to this population as well as their local circuitry and cortical depth location. Taken together, our results suggest that motor cortex is optimized to control the activity of pyramidal track neurons, embedded deep in cortex, and relaying motor commands outside of the telencephalon.

scholarly journals Functional organization of sensory input to the olfactory bulb glomerulus analyzed by two-photon calcium imaging

2004 ◽  
Vol 101 (24) ◽  
pp. 9097-9102 ◽  
Author(s):  
Matt Wachowiak ◽  
Winfried Denk ◽  
Rainer W. Friedrich
Keyword(s):  
Olfactory Bulb ◽  
Calcium Imaging ◽  
Sensory Input ◽  
Functional Organization ◽  
Two Photon

scholarly journals High resolution ultrasonic neural modulation observed via in vivo two-photon calcium imaging

2021 ◽  
Author(s):  
Zongyue Cheng ◽  
Chenmao Wang ◽  
Bowen Wei ◽  
Wenbiao Gan ◽  
Qifa Zhou ◽  
...  
Keyword(s):  
High Resolution ◽  
Calcium Imaging ◽  
Focused Ultrasound ◽  
Neuronal Response ◽  
Mammalian Brain ◽  
Label Free ◽  
High Frequency Ultrasound ◽  
Two Photon ◽  
Neural Modulation

Neural modulation plays a major role in delineating the circuit mechanisms and serves as the cornerstone of neural interface technologies. Among the various modulation mechanisms, ultrasound enables noninvasive label-free deep access to mammalian brain tissue. To date, most if not all ultrasonic neural modulation implementations are based on ~1 MHz carrier frequency. The long acoustic wavelength results in a spatially coarse modulation zone, often spanning over multiple function regions. The modulation of one brain region is inevitably linked with the modulation of its neighboring regions. To significantly increase the spatial resolution, we explored the application of high-frequency ultrasound. To investigate the neuronal response at cellular resolutions, we developed a dual-modality system combining in vivo two-photon calcium imaging and focused ultrasound modulation. The studies show that the ~30 MHz ultrasound can suppress the neuronal activity in awake mice at 100-micron scale spatial resolutions, paving the way for high-resolution ultrasonic neural modulation.

scholarly journals The unbalanced reorganization of weaker functional connections induces the altered brain network topology in schizophrenia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rossana Mastrandrea ◽  
Fabrizio Piras ◽  
Andrea Gabrielli ◽  
Nerisa Banaj ◽  
Guido Caldarelli ◽  
...  
Keyword(s):  
Resting State ◽  
Functional Organization ◽  
Functional Integration ◽  
Brain Network ◽  
Modular Organization ◽  
Node Degree ◽  
Imaging Data ◽  
Brain Disorder ◽  
Functional Connections ◽  
The Brain

AbstractNetwork neuroscience shed some light on the functional and structural modifications occurring to the brain associated with the phenomenology of schizophrenia. In particular, resting-state functional networks have helped our understanding of the illness by highlighting the global and local alterations within the cerebral organization. We investigated the robustness of the brain functional architecture in 44 medicated schizophrenic patients and 40 healthy comparators through an advanced network analysis of resting-state functional magnetic resonance imaging data. The networks in patients showed more resistance to disconnection than in healthy controls, with an evident discrepancy between the two groups in the node degree distribution computed along a percolation process. Despite a substantial similarity of the basal functional organization between the two groups, the expected hierarchy of healthy brains' modular organization is crumbled in schizophrenia, showing a peculiar arrangement of the functional connections, characterized by several topologically equivalent backbones. Thus, the manifold nature of the functional organization’s basal scheme, together with its altered hierarchical modularity, may be crucial in the pathogenesis of schizophrenia. This result fits the disconnection hypothesis that describes schizophrenia as a brain disorder characterized by an abnormal functional integration among brain regions.

scholarly journals The Modular Organization of Pain Brain Networks: An fMRI Graph Analysis Informed by Intracranial EEG

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Camille Fauchon ◽  
David Meunier ◽  
Isabelle Faillenot ◽  
Florence B Pomares ◽  
Hélène Bastuji ◽  
...  
Keyword(s):  
Information Integration ◽  
Functional Organization ◽  
Brain Connectivity ◽  
Brain Networks ◽  
Modular Organization ◽  
Noxious Heat ◽  
Intracranial Eeg ◽  
Brain Connectome ◽  
Posterior Parietal ◽  
The Brain

Abstract Intracranial EEG (iEEG) studies have suggested that the conscious perception of pain builds up from successive contributions of brain networks in less than 1 s. However, the functional organization of cortico-subcortical connections at the multisecond time scale, and its accordance with iEEG models, remains unknown. Here, we used graph theory with modular analysis of fMRI data from 60 healthy participants experiencing noxious heat stimuli, of whom 36 also received audio stimulation. Brain connectivity during pain was organized in four modules matching those identified through iEEG, namely: 1) sensorimotor (SM), 2) medial fronto-cingulo-parietal (default mode-like), 3) posterior parietal-latero-frontal (central executive-like), and 4) amygdalo-hippocampal (limbic). Intrinsic overlaps existed between the pain and audio conditions in high-order areas, but also pain-specific higher small-worldness and connectivity within the sensorimotor module. Neocortical modules were interrelated via “connector hubs” in dorsolateral frontal, posterior parietal, and anterior insular cortices, the antero-insular connector being most predominant during pain. These findings provide a mechanistic picture of the brain networks architecture and support fractal-like similarities between the micro-and macrotemporal dynamics associated with pain. The anterior insula appears to play an essential role in information integration, possibly by determining priorities for the processing of information and subsequent entrance into other points of the brain connectome.

scholarly journals Functional organization and restoration of the brain motor-execution network after stroke and rehabilitation

2015 ◽  
Vol 9 ◽  
Author(s):  
Sahil Bajaj ◽  
Andrew J. Butler ◽  
Daniel Drake ◽  
Mukesh Dhamala
Keyword(s):  
Functional Organization ◽  
Motor Execution ◽  
The Brain
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