scholarly journals Structured inhibitory activity dynamics in new virtual environments

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Moises Arriaga ◽  
Edward B Han
Keyword(s):  
Virtual Environments ◽  
Calcium Imaging ◽  
Spatial Navigation ◽  
Population Level ◽  
Two Photon ◽  
Hippocampal Ca1 ◽  
Spatial Exploration ◽  
Interneuron Activity ◽  
Stable Network ◽  
Activity Dynamics

Inhibition plays a powerful role in regulating network excitation and plasticity; however, the activity of defined interneuron types during spatial exploration remain poorly understood. Using two-photon calcium imaging, we recorded hippocampal CA1 somatostatin- and parvalbumin-expressing interneurons as mice performed a goal-directed spatial navigation task in new visual virtual reality (VR) contexts. Activity in both interneuron classes was strongly suppressed but recovered as animals learned to adapt the previously learned task to the new spatial context. Surprisingly, although there was a range of activity suppression across the population, individual somatostatin-expressing interneurons showed consistent levels of activity modulation across exposure to multiple novel environments, suggesting context-independent, stable network roles during spatial exploration. This work reveals population-level temporally dynamic interneuron activity in new environments, within which each interneuron shows stable and consistent activity modulation.

scholarly journals Two-photon calcium imaging during fictive navigation in virtual environments

2013 ◽  
Vol 7 ◽  
Author(s):  
Misha B. Ahrens ◽  
Kuo Hua Huang ◽  
Sujatha Narayan ◽  
Brett D. Mensh ◽  
Florian Engert
Keyword(s):  
Virtual Environments ◽  
Calcium Imaging ◽  
Two Photon

scholarly journals Structured Inhibitory Activity Dynamics During Learning

2019 ◽  
Author(s):  
Moises Arriaga ◽  
Edward B. Han
Keyword(s):  
Population Level ◽  
Place Cells ◽  
Network Activity ◽  
Strongly Correlated ◽  
Novel Environment ◽  
Activity Structure ◽  
Level Of Activity ◽  
Hippocampal Ca1 ◽  
Hippocampal Network ◽  
Activity Dynamics

AbstractHippocampal network activity is tightly regulated by local inhibitory interneurons. Suppression of inhibition has been proposed to accelerate learning by enhancing network activity and plasticity; however, the activity dynamics of hippocampal interneurons during learning remain poorly understood. Furthermore, it is unknown if individual interneurons are stochastically suppressed across different learning episodes, mirroring the random remapping of place cells, or if instead they exhibit consistent patterns of activity suppression. These critical properties define how inhibition shapes and controls learning at a network level. To uncover the functional circuit dynamics of inhibition during novelty-induced learning, we recorded calcium activity from hippocampal CA1 interneurons using two-photon imaging as mice learned a virtual reality (VR) goal-directed spatial navigation task in new visual contexts. Here we focused on dendrite-targeting somatostatin-expressing interneurons (SOM-ints), which powerfully control burst firing and synaptic plasticity in excitatory neurons. We found robust activity suppression in SOM-ints upon exposure to novel virtual environments; activity then recovered over repeated exposures to the novel environment as the animal learned goal locations. At a population level, we found a continuum of activity suppression, from interneurons strongly suppressed to moderately activated during learning. Surprisingly, each interneuron exhibited a stable level of activity modulation: when animals were switched into a second novel environment, the magnitude of activity suppression was strongly correlated across remapping sessions. This work reveals dynamic inhibition suppression triggered by novel environments and the gradual return of inhibition with learning. Furthermore, unlike the stochastic remapping of place cells, inhibitory networks display a stable activity structure across learning episodes. This functional inhibitory circuit architecture suggests that individual interneurons play specialized and stereotyped roles during learning, perhaps by differentially regulating pyramidal subnetworks specialized for plasticity and stability.

scholarly journals Two-photon calcium imaging of medial prefrontal cortex and hippocampus without cortical invasion

2017 ◽  
Author(s):  
Masashi Kondo ◽  
Kenta Kobayashi ◽  
Masamichi Ohkura ◽  
Junichi Nakai ◽  
Masanori Matsuzaki
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Neural Activity ◽  
Calcium Imaging ◽  
Cortical Surface ◽  
Intact Mouse ◽  
Two Photon ◽  
Ca1 Region ◽  
Hippocampal Ca1 Region ◽  
Hippocampal Ca1

AbstractIn vivo two-photon calcium imaging currently allows us to observe the activity of multiple neurons up to ∼900 μm below the cortical surface without cortical invasion. However, many other important brain areas are located deeper than this. Here, we used a 1100 nm laser, which underfilled the back aperture of the objective, and red genetically encoded calcium indicators to establish two-photon calcium imaging of the intact mouse brain and detect neural activity up to 1200 μm from the cortical surface. This imaging was obtained from the medial prefrontal cortex (the prelimbic area) and the hippocampal CA1 region. We found that the neural activity related to reward prediction is higher in the prelimbic area than in layer 2/3 of the secondary motor area, while it is negligible in the hippocampal CA1 region. Reducing the invasiveness of imaging is an important strategy to reveal the brain processes active in cognition and memory.

scholarly journals Functional Microarchitecture of the Mouse Dorsal Inferior Colliculus Revealed through In Vivo Two-Photon Calcium Imaging

2015 ◽  
Vol 35 (31) ◽  
pp. 10927-10939 ◽  
Author(s):  
O. Barnstedt ◽  
P. Keating ◽  
Y. Weissenberger ◽  
A. J. King ◽  
J. C. Dahmen
Keyword(s):  
Inferior Colliculus ◽  
Calcium Imaging ◽  
Two Photon

Two-Photon Processor and SeNeCA: a freely available software package to process data from two-photon calcium imaging at speeds down to several milliseconds per frame

2013 ◽  
Vol 110 (1) ◽  
pp. 243-256 ◽  
Author(s):  
Jakub Tomek ◽  
Ondrej Novak ◽  
Josef Syka
Keyword(s):  
Calcium Imaging ◽  
Software Package ◽  
Motion Artifacts ◽  
Calcium Signal ◽  
Neural Cells ◽  
Neuronal System ◽  
Process Data ◽  
Entire Area ◽  
Two Photon

Two-Photon Processor (TPP) is a versatile, ready-to-use, and freely available software package in MATLAB to process data from in vivo two-photon calcium imaging. TPP includes routines to search for cell bodies in full-frame (Search for Neural Cells Accelerated; SeNeCA) and line-scan acquisition, routines for calcium signal calculations, filtering, spike-mining, and routines to construct parametric fields. Searching for somata in artificial in vivo data, our algorithm achieved better performance than human annotators. SeNeCA copes well with uneven background brightness and in-plane motion artifacts, the major problems in simple segmentation methods. In the fast mode, artificial in vivo images with a resolution of 256 × 256 pixels containing ∼100 neurons can be processed at a rate up to 175 frames per second (tested on Intel i7, 8 threads, magnetic hard disk drive). This speed of a segmentation algorithm could bring new possibilities into the field of in vivo optophysiology. With such a short latency (down to 5–6 ms on an ordinary personal computer) and using some contemporary optogenetic tools, it will allow experiments in which a control program can continuously evaluate the occurrence of a particular spatial pattern of activity (a possible correlate of memory or cognition) and subsequently inhibit/stimulate the entire area of the circuit or inhibit/stimulate a different part of the neuronal system. TPP will be freely available on our public web site. Similar all-in-one and freely available software has not yet been published.

scholarly journals On the correspondence of electrical and optical physiology in in vivo population-scale two-photon calcium imaging

2019 ◽  
Author(s):  
Peter Ledochowitsch ◽  
Lawrence Huang ◽  
Ulf Knoblich ◽  
Michael Oliver ◽  
Jerome Lecoq ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Biophysical Model ◽  
Data Set ◽  
Two Photon ◽  
Simultaneous Imaging ◽  
Fluorescence Measurements ◽  
Large Populations ◽  
Intractable Problem ◽  
Mouse Lines

AbstractMultiphoton calcium imaging is commonly used to monitor the spiking of large populations of neurons. Recovering action potentials from fluorescence necessitates calibration experiments, often with simultaneous imaging and cell-attached recording. Here we performed calibration for imaging conditions matching those of the Allen Brain Observatory. We developed a novel crowd-sourced, algorithmic approach to quality control. Our final data set was 50 recordings from 35 neurons in 3 mouse lines. Our calibration indicated that 3 or more spikes were required to produce consistent changes in fluorescence. Moreover, neither a simple linear model nor a more complex biophysical model accurately predicted fluorescence for small numbers of spikes (1-3). We observed increases in fluorescence corresponding to prolonged depolarizations, particularly in Emx1-IRES-Cre mouse line crosses. Our results indicate that deriving spike times from fluorescence measurements may be an intractable problem in some mouse lines.

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.

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