Combined in vivo recording of neural signals and iontophoretic injection of pathway tracers using a hollow silicon microelectrode

Abstract

Please cite this article as: Z.Fekete, E.Pálfi, G.Márton, M.Handbauer, Zs.Bérces, I.Ulbert, A.Pongrácz, L.Négyessy, Combined in vivo recording of neural signals and iontophoretic injection of pathway tracers using a hollow silicon microelectrode, Sensors and Actuators B: Chemical http://dx.doi.org/10. 1016/j.snb.2015.12.099 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.Combined in vivo recording of neural signals and iontophoretic injection of pathway tracers using a hollow silicon microelectrode AbstractThis paper presents the results of in vivo local release of a neuronal tracer, biotinylated dextran amine (BDA) in the rat somatosensory cortex using monolithically integrated microfluidic channel of a silicon neural microelectrode. The tracer injection is controlled by iontophoresis using Pt electrodes in the vicinity of the outlet of the microfluidic channel. Using 3-5 µA, 5-7 s on/off cycle and 15-20 min total injection time the localized injection resulted in clear anterograde and retrograde BDA labeling both within the cortex and in subcortical structures. Anterograde and retrograde labeling revealed the fine details of neuronal processes including dendritic spines and axon terminal-like endings. Injection sites appeared clear lacking any strong diffuse background labeling. Electrophysiological recording performed with the same microdevice immediately after the iontophoresis indicated normal cortical functioning. The results prove that the combination of in vivo multichannel neural recording and controlled tracer injection using a single implanted microdevice is feasible, and therefore it can be a powerful tool for studying the connectome of the brain.

A silicon-based spiky probe providing improved cell accessibility during in vitro slice recordings

“…Future developments may enable such devices to be applied in both chronic and acute recordings, as well as in combination with other modalities such as intracellular recordings, combined optogenetics or microfluidic drug delivery applications [59], [60]. We showed an example for combined two-photon imaging and proposed that our spiky probe makes possible consecutive recording and imaging of the tissue at the same region.…”

Flexible deep brain neural probes based on a parylene tube structure

“…The parylene tube can also function as a microfluidic channel for chemical delivery. Such a capability is highly desirable for probing neural circuits as demonstrated by others [13,14]. Thanks to the transparency of parylene, an optical fiber can be inserted (figure 8), enabling the delivery of light to deep brain structures for optogenetic modulation.…”

“…Ultra-long silicon probes with integrated microchannels have been developed as well by Fekete and others [11,12]. Successful in vivo animal tests have been demonstrated using these multi-functional deep brain probes [13,14]. The fracture of ultra-long silicon probes with integrated microchannels has also been studied [11].…”

Recent Progress on Microelectrodes in Neural Interfaces

“…A drug delivery system is installed in the electrode to inject drugs locally. Biotinylated dextran amine (BDA), which is a neuronal tracer used both for anterograde and retrograde, is delivered locally using iontophoresis to find out the recording position [ 83 ]. Also, after dexamethasone, an anti-inflammatory drug, was loaded in the conducting polymer to inject only the electrode site, the signal was measured for more than 12 weeks [ 84 ].…”