An Integrated Method for Photothrombotic Stroke Modeling and In Vivo Optrode Recording of Neuronal and Astrocytic Activity in Behaving Mice.
Abstract:
Investigating astrocyte-neuron dynamics following ischemic stroke is essential for understanding post-stroke recovery mechanisms. However, current methodologies often fail to capture real-time interactions between neurons and astrocytes in animals executing specific behavioral tasks, limiting our ability to investigate the acute phase of stroke pathology. This protocol presents an integrated method that combines photothrombotic stroke modeling with simultaneous multichannel electrophysiology recording and fiber photometry in awake, behaving mice using a custom-fabricated optrode. The protocol includes focal ischemia induction via photothrombosis followed by simultaneous recording of neuronal spikes and astrocytic calcium transients. The optrode enables concurrent delivery of photothrombosis, calcium signal recording, and optogenetic manipulation without requiring separate surgical procedures. Representative results validate the success in simultaneous recording of astrocytic calcium signal and neuronal spiking. Optogenetic manipulation of astrocytes produces measurable changes in neuronal firing patterns (reduction in firing frequency of pyramidal neurons by 1.55 ± 0.45 Hz and interneuron by 3.64 ± 1.37 Hz compared to pre-optogenetic stimulation, n = 2), confirming that the system is capable of investigating astrocyte-neuron interactions. This integrated approach addresses critical gaps in stroke research methodology by providing real-time, multimodal recordings from the acute to chronic stage of stroke in behaving animals.
