Chronic imaging of cortical sensory map dynamics using a genetically encoded calcium indicator

• Published in: The Journal of physiology 2012-01, Vol.590 (1), p.99-107
• Main Authors: Minderer, Matthias, Liu, Wenrui, Sumanovski, Lazar T., Kügler, Sebastian, Helmchen, Fritjof, Margolis, David J.
• Format: Article
• Language: English
• Subjects: Animals; Brain Mapping - methods; Calcium; Calcium - metabolism; Calcium channels (voltage-gated); Calcium-Binding Proteins - biosynthesis; Calcium-Binding Proteins - chemistry; Calcium-Binding Proteins - genetics; Computed tomography; Cortex; Cortex (somatosensory); Dependovirus - genetics; Diagnostic Imaging - methods; Evoked Potentials, Somatosensory - physiology; Female; Fluorescence; Longitudinal Studies; Male; Mice; Mice, Inbred C57BL; Neuroimaging; Neurons - metabolism; Neurons - physiology; NMR; Nuclear magnetic resonance; Plasticity (cortical); Somatosensory Cortex - metabolism; Somatosensory Cortex - physiology; Techniques for Physiology
• ISSN: 0022-3751; 1469-7793
• DOI: 10.1113/jphysiol.2011.219014

Non‐technical summary  Optical imaging is widely used to map functional areas of the cerebral cortex. We present a method for fast fluorescence imaging of map‐level cortical activity using a calcium indicator protein. Sensory‐evoked neuronal activity can be imaged repeatedly in the same mouse over weeks, enabling new opportunities for the longitudinal study of cortical function and dysfunction. We hope this method will be flexibly applied across different cortical areas and to a variety of newly developed genetically encoded calcium and voltage sensors.   In vivo optical imaging can reveal the dynamics of large‐scale cortical activity, but methods for chronic recording are limited. Here we present a technique for long‐term investigation of cortical map dynamics using wide‐field ratiometric fluorescence imaging of the genetically encoded calcium indicator (GECI) Yellow Cameleon 3.60. We find that wide‐field GECI signals report sensory‐evoked activity in anaesthetized mouse somatosensory cortex with high sensitivity and spatiotemporal precision, and furthermore, can be measured repeatedly in separate imaging sessions over multiple weeks. This method opens new possibilities for the longitudinal study of stability and plasticity of cortical sensory representations.