scholarly journals Independent representations of reward-predicting cues and reward history in frontal cortical neurons

2020 ◽  
Author(s):  
Masashi Kondo ◽  
Masanori Matsuzaki

SummaryThe transformation of sensory inputs to appropriate goal-directed actions requires estimation of sensory-cue values based on outcome history. To clarify how cortical neurons represent an outcome-predicting cue and actual outcome, we conducted wide-field and two-photon calcium imaging of the mouse neocortex during performance of a classical conditioning task with two cues with different water-reward probabilities. Although licking behavior dominated the area-averaged activity over the whole dorsal neocortex, dorsomedial frontal cortex (dmFrC) affected other dorsal frontal cortical activities, and its inhibition extinguished differences in anticipatory licking between the cues. In individual frontal cortical neurons, the reward-predicting cue was not simultaneously represented with the current or past reward, but licking behavior was frequently multiplexed with the reward-predicting cue and current or past reward. Deep-layer neurons in dmFrC most strongly represented the reward-predicting cue and recent reward history. Our results suggest that these neurons ignite the cortical processes required to select appropriate actions.

2017 ◽  
Author(s):  
Siegfried Weisenburger ◽  
Robert Prevedel ◽  
Alipasha Vaziri

AbstractConsiderable efforts are currently being devoted to enhance the speed, spatial resolution and the size of the 3D sample volumes in which calcium imaging methods can capture neuronal network activity in different model systems. In the mammalian brain, tissue scattering severely limits the use of parallel acquisition techniques such as wide-field imaging and, as a consequence, methods based on two-photon point-scanning (2PM) have become the method of choice. However, 2PM faces severe restrictions due to technical limitations such as scan speed, laser power, and those related to the fluorescent probes, calling for conceptually new approaches to enhance the performance of two-photon calcium imaging schemes. Here we provide a detailed quantitative evaluation and comparison of different excitation/detection modalities from the perspective of detecting neuronal activity that are based on different point-spread functions (PSF), laser repetition rates and sampling strategies. We demonstrate the conditions for which imaging speed and signal-to-noise ratio are optimized for a given average power. Our results are based on numerical simulations which are informed by experimentally measured parameters and show that volumetric field of view and acquisition speed can be considerably improved compared to traditional 2PM schemes by a holistic optimization approach.


2021 ◽  
Author(s):  
Yiyi Yu ◽  
Jeffrey N. Stirman ◽  
Christopher R. Dorsett ◽  
Spencer L. Smith

Mice have a constellation of higher visual areas, but their functional specializations are unclear. Here, we used a data-driven approach to examine neuronal representations of complex visual stimuli across mouse higher visual areas, measured using large field-of-view two-photon calcium imaging. Using specialized stimuli, we found higher fidelity representations of texture in area LM, compared to area AL. Complementarily, we found higher fidelity representations of motion in area AL, compared to area LM. We also observed this segregation of information in response to naturalistic videos. Finally, we explored how popular models of visual cortical neurons could produce the segregated representations of texture and motion we observed. These selective representations could aid in behaviors such as visually guided navigation.


2020 ◽  
Author(s):  
Ting Fu ◽  
Isabelle Arnoux ◽  
Jan Döring ◽  
Hirofumi Watari ◽  
Ignas Stasevicius ◽  
...  

AbstractTwo-photon (2-P) all-optical approaches combine in vivo 2-P calcium imaging and 2-P optogenetic modulations and have the potential to build a framework for network-based therapies, e.g. for rebalancing maladaptive activity patterns in preclinical models of neurological disorders. Here, our goal was to tailor these approaches for this purpose: Firstly, we combined in vivo juxtacellular recordings and GCaMP6f-based 2-P calcium imaging in layer II/III of mouse visual cortex to tune our detection algorithm towards a 100 % specific identification of AP-related calcium transients. False-positive-free detection was achieved at a sensitivity of approximately 73 %. To further increase specificity, secondly, we minimized photostimulation artifacts as a potential source for false-positives by using extended-wavelength-spectrum laser sources for optogenetic stimulation of the excitatory opsin C1V1. We achieved artifact-free all-optical experiments performing photostimulations at 1100 nm or higher and simultaneous calcium imaging at 920 nm in mouse visual cortex in vivo. Thirdly, we determined the spectral range for maximizing efficacy of optogenetic control by performing 2-P photostimulations of individual neurons with wavelengths up to 1300 nm. The rate of evoked transients in GCaMP6f/C1V1-co-expressing cortical neurons peaked already at 1100 nm. By refining spike detection and defining 1100 nm as the optimal wavelength for artifact-free and effective stimulations of C1V1 in GCaMP-based all-optical interrogations, we increased the translational value of these approaches, e.g. for the use in preclinical applications of network-based therapies.One Sentence SummaryWe maximize translational relevance of 2-P all-optical physiology by increasing specificity, minimizing artifacts and optimizing stimulation efficacy.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Joshua H Siegle ◽  
Peter Ledochowitsch ◽  
Xiaoxuan Jia ◽  
Daniel J Millman ◽  
Gabriel K Ocker ◽  
...  

Extracellular electrophysiology and two-photon calcium imaging are widely used methods for measuring physiological activity with single-cell resolution across large populations of cortical neurons. While each of these two modalities has distinct advantages and disadvantages, neither provides complete, unbiased information about the underlying neural population. Here, we compare evoked responses in visual cortex recorded in awake mice under highly standardized conditions using either imaging of genetically expressed GCaMP6f or electrophysiology with silicon probes. Across all stimulus conditions tested, we observe a larger fraction of responsive neurons in electrophysiology and higher stimulus selectivity in calcium imaging, which was partially reconciled by applying a spikes-to-calcium forward model to the electrophysiology data. However, the forward model could only reconcile differences in responsiveness when restricted to neurons with low contamination and an event rate above a minimum threshold. This work established how the biases of these two modalities impact functional metrics that are fundamental for characterizing sensory-evoked responses.


Author(s):  
Misha B. Ahrens ◽  
Kuo Hua Huang ◽  
Sujatha Narayan ◽  
Brett D. Mensh ◽  
Florian Engert

2015 ◽  
Vol 35 (31) ◽  
pp. 10927-10939 ◽  
Author(s):  
O. Barnstedt ◽  
P. Keating ◽  
Y. Weissenberger ◽  
A. J. King ◽  
J. C. Dahmen

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