A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats

Abstract

Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury.

A Wearable Fiber-Free Optical Sensor for Continuous Monitoring of Cerebral Blood Flow in Freely Behaving Mice

“…Traditional CBF modalities are generally ill-suited towards applications involving moving subjects, continuous measurements, and/or longitudinal exposure. In response, a variety of wearable technologies have been attempted for continuously monitoring the brain of awake rodents [15][16][17][18][19][20]. Wearable microscopes including head-mounted 2-photon microscopes, miniature endoscopes, fiber photometers, laser speckle contrast imaging (LSCI), and calcium fluorescent probes have already made significant contributions to neuroscience [18,19,[21][22][23].…”

The Future of Neuroscience: Flexible and Wireless Implantable Neural Electronics

“…Headstages are employed both in wireless and wired systems, although a wired system must also include an external connector. Incorporating recording electronics and signal enhancement, [ 304 ] Limnuson et al. combine a straightforward wired design with a rotating commutator to allow for rats to move unimpeded.…”

“…Headstages are employed both in wireless and wired systems, although a wired system must also include an external connector. Incorporating recording electronics and signal enhancement, [304] Limnuson et al combine a straightforward wired design with a rotating commutator to allow for rats to move unimpeded. The headstage may also be used to protect the implant inside a rodent brain, preventing trauma which will damage the neural probe and the rodent itself: alleviating this risk means that rats may be pair-housed in a more natural, stimulating environment.…”