Visualizing neuronal activity in the brain in vivo is a crucial task in modern neurobiology. Imaging changes in the neuronal networks of various brain regions in neurodegenerative diseases, such as Alzheimer’s disease, can uncover functional aberrations in neuronal connections during their early stages. One current method of obtaining in vivo neural activity data is the miniscopic fluorescence microscopy technique, which facilitates in vivo registration of excitation within the neural networks of brain areas, followed by subsequent analysis [1]. The Miniscope, a miniature fluorescence microscope, enables researchers to work with freely moving laboratory animals, which sets it apart from other in vivo imaging methods, such as two-photon microscopy.
In this study, we injected an adeno-associated virus containing the GCaMP6f gene, which encodes a fluorescent calcium-sensitive protein, into the somatosensory cortex region of the brain at coordinates AP-2.1, ML+2.1, DV-0.05). We conducted the in vivo recording of calcium level changes in 3-month-old C57BL/6J mice by placing a 5×5 mm clear glass cranial window over the injection site of the virus. After 4 weeks, we placed and fixed a Baseplate over this cranial window to hold the Miniscope V4 over the clear cover glass for efficient recording.
In future studies, researchers will introduce the adeno-associated virus carrying the GCaMP6f protein gene into the somatosensory cortex of 3-month-old 5xFAD mice with Alzheimer’s disease to compare the activity of somatosensory cortex neural networks in free-ranging wild-type mice and 5xFAD mice, and detect differences in the functioning of these neural networks. Additionally, they will place a clear glass cranial window over the somatosensory cortex to install Miniscope V4. As these studies advance, Miniscope V4 data on somatosensory neuron activity in wild-type (C57BL/6J line) and Alzheimer’s disease transgenic mice (5xFAD line) will be utilized to evaluate somatosensory neural network states during assorted behavioral tests. Future studies will analyze the somatosensory cortex neuron activity during vibrissae stimulation, as abnormally high neuronal population activity in the somatosensory cortex has been observed in 5xFAD line mice with Alzheimer’s disease [2]. These findings will be crucial in the pharmacological assessment of potential therapeutic agents for Alzheimer’s disease treatment.
