Hybrid photoacoustic and electrophysiological recording of neurovascular communications in freely-moving rats.

Uncovering the relationships between neural activities and capillary-level hemodynamics such as blood flow and concentration of hemoglobin in the brain plays an important role in the study of animal behaviors and brain disorders. Here, we developed a miniature probe integrating a photoacoustic sensor and micro-electrodes to simultaneously record the dynamics of blood flow and total hemoglobin inside a single capillary and the activities of surrounding neurons with high spatiotemporal resolution in freely-moving rats. In the somatosensory cortex of rats, we observed: 1) early hemodynamic response prior to the changes in local field potential during pentylenetetrazol-induced localized and generalized seizure onsets in both freely-moving and anesthetized rats; and 2) different hemodynamic and neural responses to generalized seizure onsets between freely-moving and anaesthetized rats. These findings suggest that this high-resolution hybrid technique will enable a wide range of new studies of behaviors and brain disorders in small animals.

Image-guided surgery using multimodality strategy and molecular probes.

The ultimate goal of cancer surgery is to maximize the excision of tumorous tissue with minimal damage to the collateral normal tissues, reduce the postoperative recurrence, and improve the survival rate of patients. In order to locate tumor lesions, highlight tumor margins, visualize residual disease in the surgical wound, and map potential lymph node metastasis, various imaging techniques and molecular probes have been investigated to assist surgeons to perform more complete tumor resection. Combining imaging techniques with molecular probes is particularly promising as a new approach for image-guided surgery. Considering inherent limitations of different imaging techniques and insufficient sensitivity of nonspecific molecular probes, image-guided surgery with multimodality strategy and specific molecular probes appears to be an optimal choice. In this article, we briefly describe typical imaging techniques and molecular probes followed by a focused review on the current progress of multimodal image-guided surgery with specific molecular navigation. We also discuss optimal strategy that covers all stages of image-guided surgery including preoperative scanning of tumors, intraoperative inspection of surgical bed and postoperative care of patients.