Bulk Dye Loading for In Vivo Calcium Imaging of Visual Responses in Populations of Xenopus Tectal Neurons

2021 ◽  
Vol 2022 (1) ◽  
pp. pdb.prot106831
Author(s):  
Peter W. Hogg ◽  
Kurt Haas
Keyword(s):  
Optic Tectum ◽  
Image Plane ◽  
Time Lapse ◽  
Visual Responses ◽  
Easy Method ◽  
Tectal Neurons ◽  
Evoked Activity ◽  
Sensory Evoked ◽  
Time Lapse Imaging

Bulk loading of neurons with fluorescent calcium indicators in transparent albino Xenopus tadpoles offers a rapid and easy method for tracking sensory-evoked activity in large numbers of neurons within an awake developing brain circuit. In vivo two-photon time-lapse imaging of an image plane through the optic tectum allows defining receptive field properties from visual-evoked responses for studies of single-neuron and network-level encoding and plasticity. Here, we describe loading the Xenopus tadpole optic tectum with the membrane-permeable AM ester of Oregon Green 488 BAPTA-1 (OGB-1 AM) for in vivo imaging experiments.

scholarly journals Experience-dependent plasticity of excitatory and inhibitory intertectal inputs in Xenopus tadpoles

2016 ◽  
Vol 116 (5) ◽  
pp. 2281-2297 ◽  
Author(s):  
Abigail C. Gambrill ◽  
Regina L. Faulkner ◽  
Hollis T. Cline
Keyword(s):  
Visual Experience ◽  
Sensory Information ◽  
Time Lapse ◽  
Functional Development ◽  
Circuit Development ◽  
Tectal Neurons ◽  
Intertectal Connections ◽  
Post Hoc ◽  
Time Lapse Imaging

Communication between optic tecta/superior colliculi is thought to be required for sensorimotor behaviors by comparing inputs across the midline; however, the development of and the role of visual experience in the function and plasticity of intertectal connections are unclear. We combined neuronal labeling, in vivo time-lapse imaging, and electrophysiology to characterize the structural and functional development of intertectal axons and synapses in Xenopus tadpole optic tectum. We find that intertectal connections are established early during optic tectal circuit development. We determined the neurotransmitter identity of intertectal neurons using both rabies virus-mediated tracing combined with post hoc immunohistochemistry and electrophysiology. Excitatory and inhibitory intertectal neuronal somata are similarly distributed throughout the tectum. Excitatory and inhibitory intertectal axons are structurally similar and elaborate broadly in the contralateral tectum. We demonstrate that intertectal and retinotectal axons converge onto tectal neurons by recording postsynaptic currents after stimulating intertectal and retinotectal inputs. Cutting the intertectal commissure removes synaptic responses to contralateral tectal stimulation. In vivo time-lapse imaging demonstrated that visual experience drives plasticity in intertectal bouton size and dynamics. Finally, visual experience drives the maturation of excitatory intertectal inputs by increasing AMPA-to- N-methyl-d-aspartate (NMDA) ratios, comparable to experience-dependent maturation of retinotectal inputs, and coordinately increases intertectal GABA receptor-mediated currents. These data indicate that visual experience regulates plasticity of excitatory and inhibitory intertectal inputs, maintaining the balance of excitatory to inhibitory intertectal input. These studies place intertectal inputs as key players in tectal circuit development and suggest that they may play a role in sensory information processing critical to sensorimotor behaviors.

scholarly journals Multisensory Integration in Mesencephalic Trigeminal Neurons in Xenopus Tadpoles

2009 ◽  
Vol 102 (1) ◽  
pp. 399-412 ◽  
Author(s):  
Kara G. Pratt ◽  
Carlos D. Aizenman
Keyword(s):  
Optic Tectum ◽  
Motor Nucleus ◽  
Visual Responses ◽  
Trigeminal Motor Nucleus ◽  
Electrophysiological Properties ◽  
Somatosensory Information ◽  
Somatosensory Neurons ◽  
Tectal Neurons

Mesencephalic trigeminal (M-V) neurons are primary somatosensory neurons with somata located within the CNS, instead of in peripheral sensory ganglia. In amphibians, these unipolar cells are found within the optic tectum and have a single axon that runs along the mandibular branch of the trigeminal nerve. The axon has collaterals in the brain stem and is believed to make synaptic contact with neurons in the trigeminal motor nucleus, forming part of a sensorimotor loop. The number of M-V neurons is known to increase until metamorphosis and then decrease, suggesting that at least some M-V neurons may play a transient role during tadpole development. It is not known whether their location in the optic tectum allows them to process both visual and somatosensory information. Here we compare the anatomical and electrophysiological properties of M-V neurons in the Xenopus tadpole to principal tectal neurons. We find that, unlike principal tectal cells, M-V neurons can sustain repetitive spiking when depolarized and express a significant H-type current. M-V neurons could also be driven synaptically by visual input both in vitro and in vivo, but visual responses were smaller and longer-lasting than those seen in principal tectal neurons. We also found that the axon of M-V neurons appears to directly innervate a tentacle found in the corner of the mouth of premetamorphic tadpoles. Electrical stimulation of this transient sensory organ results in antidromic spiking in M-V neurons in the tectum. Thus M-V neurons may play an integrative multisensory role during tadpole development.

scholarly journals Network activity influences the subthreshold and spiking visual responses of pyramidal neurons in the three-layer turtle cortex

2017 ◽  
Vol 118 (4) ◽  
pp. 2142-2155 ◽  
Author(s):  
Nathaniel C. Wright ◽  
Ralf Wessel
Keyword(s):  
Membrane Potential ◽  
Cortical Neurons ◽  
Visual Stimulation ◽  
Cortical Activity ◽  
Network Activity ◽  
Visual Responses ◽  
Up States ◽  
Evoked Activity ◽  
Sensory Evoked

A primary goal of systems neuroscience is to understand cortical function, typically by studying spontaneous and stimulus-modulated cortical activity. Mounting evidence suggests a strong and complex relationship exists between the ongoing and stimulus-modulated cortical state. To date, most work in this area has been based on spiking in populations of neurons. While advantageous in many respects, this approach is limited in scope: it records the activity of a minority of neurons and gives no direct indication of the underlying subthreshold dynamics. Membrane potential recordings can fill these gaps in our understanding, but stable recordings are difficult to obtain in vivo. Here, we recorded subthreshold cortical visual responses in the ex vivo turtle eye-attached whole brain preparation, which is ideally suited for such a study. We found that, in the absence of visual stimulation, the network was “synchronous”; neurons displayed network-mediated transitions between hyperpolarized (Down) and depolarized (Up) membrane potential states. The prevalence of these slow-wave transitions varied across turtles and recording sessions. Visual stimulation evoked similar Up states, which were on average larger and less reliable when the ongoing state was more synchronous. Responses were muted when immediately preceded by large, spontaneous Up states. Evoked spiking was sparse, highly variable across trials, and mediated by concerted synaptic inputs that were, in general, only very weakly correlated with inputs to nearby neurons. Together, these results highlight the multiplexed influence of the cortical network on the spontaneous and sensory-evoked activity of individual cortical neurons. NEW & NOTEWORTHY Most studies of cortical activity focus on spikes. Subthreshold membrane potential recordings can provide complementary insight, but stable recordings are difficult to obtain in vivo. Here, we recorded the membrane potentials of cortical neurons during ongoing and visually evoked activity. We observed a strong relationship between network and single-neuron evoked activity spanning multiple temporal scales. The membrane potential perspective of cortical dynamics thus highlights the influence of intrinsic network properties on visual processing.

scholarly journals Optogenetic Modulation of a Minor Fraction of Parvalbumin-Positive Interneurons Specifically Affects Spatiotemporal Dynamics of Spontaneous and Sensory-Evoked Activity in Mouse Somatosensory Cortex in Vivo

2017 ◽  
Vol 27 (12) ◽  
pp. 5784-5803 ◽  
Author(s):  
Jenq-Wei Yang ◽  
Pierre-Hugues Prouvot ◽  
Vicente Reyes-Puerta ◽  
Maik C Stüttgen ◽  
Albrecht Stroh ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Spatiotemporal Dynamics ◽  
Minor Fraction ◽  
Evoked Activity ◽  
Sensory Evoked ◽  
A Minor

Topical Review: Neuronal Migration in Cortical Development

2004 ◽  
Vol 19 (3) ◽  
pp. 274-279
Author(s):  
Shigeaki Kanatani ◽  
Hidenori Tabata ◽  
Kazunori Nakajima
Keyword(s):  
Neuronal Migration ◽  
Radial Glia ◽  
Asymmetric Cell Division ◽  
Time Lapse ◽  
Radial Glial Cells ◽  
Daughter Cells ◽  
Radial Glial ◽  
Time Lapse Imaging ◽  
Mitotic Behavior

Cortical formation in the developing brain is a highly complicated process involving neuronal production (through symmetric or asymmetric cell division) interaction of radial glia with neuronal migration, and multiple modes of neuronal migration. It has been convincingly demonstrated by numerous studies that radial glial cells are neural stem cells. However, the processes by which neurons arise from radial glia and migrate to their final destinations in vivo are not yet fully understood. Recent studies using time-lapse imaging of neuronal migration are giving investigators an increasingly more detailed understanding of the mitotic behavior of radial glia and the migrating behavior of their daughter cells. In this review, we describe recent progress in elucidating neuronal migration in brain formation and how neuronal migration is disturbed by mutations in genes that control this process. ( J Child Neurol 2005;20:274—279).

scholarly journals Individual neuronal subtypes control initial myelin sheath growth and stabilization

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Heather N. Nelson ◽  
Anthony J. Treichel ◽  
Erin N. Eggum ◽  
Madeline R. Martell ◽  
Amanda J. Kaiser ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Myelin Sheath ◽  
Time Lapse ◽  
Marked Individual ◽  
Larval Zebrafish ◽  
Sheath Formation ◽  
Time Lapse Imaging

Abstract Background In the developing central nervous system, pre-myelinating oligodendrocytes sample candidate nerve axons by extending and retracting process extensions. Some contacts stabilize, leading to the initiation of axon wrapping, nascent myelin sheath formation, concentric wrapping and sheath elongation, and sheath stabilization or pruning by oligodendrocytes. Although axonal signals influence the overall process of myelination, the precise oligodendrocyte behaviors that require signaling from axons are not completely understood. In this study, we investigated whether oligodendrocyte behaviors during the early events of myelination are mediated by an oligodendrocyte-intrinsic myelination program or are over-ridden by axonal factors. Methods To address this, we utilized in vivo time-lapse imaging in embryonic and larval zebrafish spinal cord during the initial hours and days of axon wrapping and myelination. Transgenic reporter lines marked individual axon subtypes or oligodendrocyte membranes. Results In the larval zebrafish spinal cord, individual axon subtypes supported distinct nascent sheath growth rates and stabilization frequencies. Oligodendrocytes ensheathed individual axon subtypes at different rates during a two-day period after initial axon wrapping. When descending reticulospinal axons were ablated, local spinal axons supported a constant ensheathment rate despite the increased ratio of oligodendrocytes to target axons. Conclusion We conclude that properties of individual axon subtypes instruct oligodendrocyte behaviors during initial stages of myelination by differentially controlling nascent sheath growth and stabilization.

In Vivo Time-Lapse Imaging of Neuronal Development inXenopus

2013 ◽  
Vol 2013 (9) ◽  
pp. pdb.top077156 ◽  
Author(s):  
Edward S. Ruthazer ◽  
Anne Schohl ◽  
Neil Schwartz ◽  
Aydin Tavakoli ◽  
Marc Tremblay ◽  
...  
Keyword(s):  
Neuronal Development ◽  
Time Lapse ◽  
Time Lapse Imaging
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