Name: Video: Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy
Uploaded: 2023-11-21T14:00:00
Description: 60 Views. Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy

imaging single cell-level activity in neonatal mice using two-photon microscopy

Neuronal Activity Mapping in Developing Mouse Sensory Cortex

The cerebral cortex contains several sensory areas with distinct functions. The areas receive inputs originating from their corresponding sensory organs, mostly conveyed through the spinal cord or brainstem and relayed via the thalamus1,2. Notably, neurons in each primary sensory area exhibit uniquely synchronized activity during early developmental stages, which also originate from sensory organs or the lower nervous centers, but essentially differ from the activities observed in the mature cortex3.
In neonatal rodents, for example, the primary visual area (V1) displays wave-like activity, which originates in the retina (retinal wave) and propagates through the entire visual pathway while conserving retinotopy4. The primary auditory area (A1) exhibits synchronous activity organized in band-shaped subregions that correspond to the isofrequency bands in the mature brain. The activity emanates from the cochlea&#39;s inner hair cells5,6. The barrel cortex in the primary somatosensory area (S1) shows a patchwork-like activity pattern in which layer 4 neurons within individual barrels, namely, neurons responsive to individual whiskers, are synchronously activated7. Although proposed to originate from the trigeminal ganglion, the source of the activity remains unknown7. Consequently, neonatal activity patterns are specialized both within each primary sensory area and within intra-areal subfields. The simultaneous visualization of neuronal activity and structure of primary sensory areas may facilitate an inquiry into the contribution of these activity patterns to the development of sensory systems.
In this article, we summarized a series of protocols: (1) to visualize individual neuronal activities using sparse labeling of GCaMP and primary sensory areas using TCA-RFP mice that express red fluorescent protein in thalamocortical axons7, (2) to image single cell-level activity in neonatal mice using two-photon microscopy in vivo, and (3) to analyze the activity correlations within S1 barrel cortex. The representative results show patchwork-like synchronized activity within individual barrels of a postnatal day (P)6 mouse. Despite some limitations, this technique can be used for chronic imaging, wide-field imaging across multiple sensory areas, and various manipulation experiments. The multifaceted analysis of neuronal activity during development will enrich our comprehension of brain circuit formation mechanisms.

Author Spotlight: Deciphering Neural Circuit Formation from Two-Photon Microscopy and Single Neuron Imaging

In Vivo Visualization of Spontaneous Activity in Neonatal Mouse Sensory Cortex at a Single-Neuron Resolution

Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy

imaging-single-cell-level-activity-neonatal-mice-using-two-photon

Research

JoVE Journal

Neuroscience

60 Views. Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy

Video: Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy

The mammalian brain undergoes dynamic developmental changes at both the cellular and circuit levels throughout prenatal and postnatal periods. Following the discovery of numerous genes contributing to these developmental changes, it is now known that neuronal activity also substantially modulates these processes. In the developing cerebral cortex, neurons exhibit synchronized activity patterns that are specialized to each primary sensory area. These patterns markedly differ from those observed in the mature cortex, emphasizing their role in regulating area-specific developmental processes. Deficiencies in neuronal activity during development can lead to various brain diseases. These findings highlight the need to examine the regulatory mechanisms underlying activity patterns in neuronal development. This paper summarizes a series of protocols to visualize primary sensory areas and neuronal activity in neonatal mice, to image the activity of individual neurons within the cortical subfields using two-photon microscopy in vivo, and to analyze subfield-related activity correlations. We show representative results of patchwork-like synchronous activity within individual barrels in the somatosensory cortex. We also discuss various potential applications and some limitations of this protocol.

Primary sensory areas in the neocortex exhibit unique spontaneous activities during development. This article describes how to visualize individual neuron activities and primary sensory areas to analyze area-specific synchronous activities in neonatal mice in vivo.

The mammalian brain undergoes dynamic developmental changes at both the cellular and circuit levels throughout prenatal and postnatal periods. Following ...

Methods Article

Imaging Single Cell-Level Activity in Neonatal Mice Using Two-Photon Microscopy