JP3496056B2 - Nerve bundle-coupled high-density multipolar electrodes for peripheral nerve stimulation and recording - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nerve bundle coupling type high density multipolar electrode.

[0002]

2. Description of the Related Art Two-dimensional high density multi-point electrodes have been developed mainly for stimulating and recording nerve cells in a culture system. Cuffs, needles, and regenerative types have been developed as electronic devices for living organisms, especially peripheral nerve bundles, but since cufflinks wind an electrode plate around the nerve bundle, fine adjustment cannot be performed at all. It was Further, in the case of the needle type electrode, the electrode cannot be fixed, and it is difficult to continuously stimulate and record the same nerve fiber. Further, in the regenerative electrode, the nerve fibers are regenerated and enter the electrode holes, so that the nerve fiber bundle must be cut, which is highly invasive.

According to the present invention, (1) it is possible to stably bind and fix nerve fibers to electrodes individually without cutting nerve bundles, and (2) simultaneously stimulate and record many peripheral nerve fibers. It is an object of the present invention to provide an electrode that can be manufactured.

[0004]

The present invention relates to the following multipolar electrode. Item 1. Arrange multiple electrodes on the insulating substrate at a predetermined interval,
A nerve bundle coupling type high-density multipolar electrode, wherein an insulating wall covering a lead wire extending from the electrode is arranged in a slit shape. Item 2. Item 2. The multipolar electrode according to Item 1, wherein the electrode portions are arranged in two or more areas.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the insulating base material of the present invention,
A transparent substrate is preferable for observing nerve cells, and glass such as quartz glass, lead glass, borosilicate glass, or an inorganic substance such as quartz, or polymethylmethacrylate or its copolymer, polystyrene, polyvinyl chloride ,
Examples include transparent organic substances such as polyester, polypropylene, urea resin, and melamine resin, and inorganic substances are preferable in consideration of mechanical strength and transparency.

In the present invention, as the electrode material, indium tin oxide (ITO), tin oxide, Cr, Au, Cu,
Ni, Al, etc. are mentioned, Preferably Ni, Au etc. are illustrated. Examples of the shape of the electrode include a circular shape, a rectangular shape, and a square shape. The radius of the electrode (in the case of a circle) or the length of one side (in the case of a rectangle or a square), 10 to 50.
μm, preferably about 30 μm.

Examples of the lead wire material include indium tin oxide (ITO), tin oxide, Cr, Au, Cu, Ni and Al, and preferably Ni and Au are exemplified.
Usually, these electrodes and lead wires can be formed in a desired pattern by vapor-depositing these electrode or lead wire materials on an insulating substrate and etching using a photoresist.

The distance between the electrodes is about 10 to 1000 μm, preferably about 30 to 50 μm. It is preferable to change the distance between the electrodes in a plurality of portions on one substrate because nerve fibers of various thicknesses can be fixed on the substrate.

The number of electrodes in the electrode portion where the electrodes are arranged at a high density is about 5 to 100, preferably 10 to 50.
The number of electrodes is about one, and two or more electrode dense portions can be provided on one substrate.

As the insulating layer material for insulating the lead wires, for example, polyimide (PI) resin, epoxy resin,
Examples include transparent resins such as acrylate resins, polyester resins, and polyamide resins.

These resins are coated on the lead wire by a usual method to form an insulating layer. In addition, it is preferable that the insulating layer material is a photosensitive resin such as a photopolymerizable resin because it is possible to form a pattern such as forming a hole in the insulating layer portion on the electrode to expose the electrode.

The thickness of the insulating layer is not particularly limited as long as it can impart the insulating property, but it is usually preferably 20 to 30 μm.

The distance between adjacent electrodes of the multipoint electrode of the present invention is 1
0 to 1000 μm is preferable, and more preferably 30 to 5
It is 0 μm.

In the present invention, it is preferable that only a part of the electrode is exposed and the peripheral portion of the electrode is covered with an insulating material. Further, the peripheral portion of the electrode is entirely covered with an insulating material.

The lead wire extending from the electrode is covered with an insulating wall, and the insulating wall is arranged in a slit shape, and by arranging the nerve fiber between the insulating walls, stimulation and recording of the nerve fiber are paired. This can be done with electrodes.

The insulating wall can be formed of a synthetic resin material such as acrylic.

By culturing nerve cells on the multipolar electrode of the present invention, it is possible to record the cultured nerve cells.

When the multipoint electrode of the present invention is used, electrical stimulation is continuously applied to cells for a time of about 1 to 5 hours,
Moreover, the electrical activity of cells can be measured and recorded.

[0019]

EFFECTS OF THE INVENTION According to the present invention, (1) it is possible to stably bind and fix nerve fibers individually to electrodes without cutting nerve bundles, and (2) stimulation of many peripheral nerve fibers. It is possible to provide an electrode capable of recording simultaneously.

[0020]

EXAMPLES The present invention will be described in more detail based on the following examples.

Specific preferred examples of the electrode of the present invention are shown in the following (1) to (8) and FIG. (1) The interface is based on MED systems. (2) Ni / Au with 68 poles (4 of which are not connected)
Fabricate by patterning (3) Two stages are placed 5mm apart facing each other on the glass substrate (4) Two rows × 17 electrodes are placed on each stage (5) To fix nerve bundles on each stage Acrylic insulating wall 25 μm high is arranged in a slit shape so that the part where the electrode is located becomes a valley (6) The electrode part has three types of widths to accommodate different nerve bundle thicknesses (7) One The size of the gold electrode is the minimum width of 34 μm x 3
4 μm (8) Electronic circuit on substrate was prepared by forming ITO pattern. Specifically, Ni / A was used for the material of electrode 1 and lead wire 2.
Using u, vapor deposition was performed to a thickness of about 0.54 μm on the entire surface of the glass substrate 3, and then the glass substrate 3 was washed. Next, exposure was performed using a photoresist so that the pattern of the electrode 1 and the lead wire 2 having the shape of FIG. 1 was obtained, Ni / Au was etched, and then the photoresist was removed. Electrode 1 is 34μm x 50μ
m, width of lead wire 2 is 30 μm, distance between electrode centers is 12
A wiring portion of 5 μm was formed.

The multi-point electrode substrate of the present invention was obtained by arranging 25 μm high acrylic insulating walls in a slit shape on the substrate having the obtained wiring portion and covering the lead wires not covered with the acrylic insulating wall with an insulating material. Formed. Example 1 (I) Coupling of nerve coupling electrodes (FIG. 2) A peripheral nerve bundle or a part thereof was coupled to a coupling electrode actually designed and developed. The sciatic nerves of rat pups on the 1st, 7th, and 14th days after birth were exposed, and the nerve bundles were arranged in the slits on the substrate. Under pentobarbital anesthesia (7th day and 14th day old rats) or cryogenic anesthesia (1st day old rat), the epidermis was cut open from the back of the thigh to the buttocks, and adipose tissue was appropriately removed. Furthermore, the perineurium was dissected to expose the deep sciatic nerve. These nerve bundles were placed on the nerve bundle connecting electrode under a stereoscopic microscope, and a nerve bundle having an appropriate thickness was placed in the electrode slit. Some nerve bundles are trypsin (0.1%, Sigma), which is a proteolytic enzyme, and dispase (500 protease units / m) that decomposes extracellular matrix.
(1. Godo Shusei Co., Ltd.), the connective tissues of the perineurium and the endometrium surrounding the nerve bundle were decomposed at 37 ° C. for 30 minutes to 1 hour. Then, after washing twice with a phosphate buffer and further with DME medium, the nerve bundle was placed on the nerve bundle-binding electrode. (II) Measurement of nerve activity recording It is easy to stimulate the nerve bundle, but it is relatively difficult to actually record it. Therefore, we demonstrated that this electrode can actually record neural activity using a cultured cell system.

The material used was the spinal cord and dorsal root ganglia of the fetus on the 1st or 18th day after birth of the rat. On the 1st day after birth, the rat was separated from the trunk under ice anesthesia, and further examined under a stereomicroscope. The spinal cord and dorsal root ganglia were removed. The extracted nerve tissue is temporarily stored in DME medium, and 1) the method of placing the extracted ganglion and part of the spinal cord on the spot of collagen gel, and 2) the method of dissociation culture by treating with trypsin. I went. An electrode for binding nerve bundles coated with polyethyleneimine was placed on a 100 mm petri dish, and DME medium (10% FCS, P / S, Insuline was placed in a circular frame).
1.8 ml) was added. See Figure 3 for the appearance of cultured neurons. A neural activity record as shown in FIG. 4 could be obtained from the electrode indicated by an arrow in FIG.

[Brief description of drawings]

FIG. 1 shows an enlarged view of each part of a multipoint electrode of the present invention.

FIG. 2 shows coupling of partial nerve bundles to electrodes.

FIG. 3 shows the results of culturing rat spinal nerve cells on nerve electrodes.

FIG. 4 shows the obtained neural recording.

[Explanation of symbols]

1 electrode 2 lead wire 3 glass substrates 4 insulating walls 5 nerve bundle

Claims (2)

(57) [Claims] 1. A plurality of electrodes are arranged at a predetermined interval on an insulating substrate, and an insulating wall covering a lead wire extending from the electrodes is provided as an electrode.
A nerve-bundle-coupled high-density multipolar electrode, which is characterized in that it is arranged in a slit shape so that a certain portion is a valley . 2. The multipolar electrode according to claim 1, wherein the electrode parts are arranged in two or more areas.