Cerebral blood flow patterns induced by photoactivation based on laser speckle contrast imaging.

Abstract

Neurovascular coupling (NVC) is crucial for maintaining brain function and holds significant implications for diagnosing neurological disorders. However, the neuron type and spatial specificity in NVC remain poorly understood. In this study, we investigated the spatiotemporal characteristics of local cerebral blood flow (CBF) driven by excitatory (VGLUT2) and inhibitory (VGAT) neurons in the mouse sensorimotor cortex. By integrating optogenetics, wavefront modulation technology, and laser speckle contrast imaging (LSCI), we achieved precise, spatially targeted photoactivation of type-specific neurons and real-time CBF monitoring. We observed three distinct CBF response patterns across different locations: unimodal, bimodal, and biphasic. While unimodal and bimodal patterns were observed in different locations for both neuron types, the biphasic pattern was exclusive to inhibitory neurons. Our results reveal the spatiotemporal complexity of NVC across different neuron types and demonstrate our method's ability to analyze this complexity in detail.