Abstract: A system and method for monitoring electrophysiological information from a tissue slice includes at least one probe having a plurality of electrodes. The system also comprises a controller configured to select tissue sites to be monitored and to be electrically stimulated. In one variation of the invention, a plurality of multi-electrode probes are managed by the controller. The system may further include a plurality of amplifier modules, one amplifier module associated with each probe. The amplifier module may serve a number of functions including amplifying electrical signals sensed by the electrodes, distributing stimulation signals to selected electrodes, and filtering signals evoked from the tissue sites. The system can provide automatic selection and switching of electrodes for monitoring and stimulating multiple tissue sites. Multiple probes, each adapted to monitor multiple tissue sites, may be associated with the controller such that multiple tissue slices may be interrogated in parallel.

Abstract: The invention relates to systems and methods for assessing neuronal degeneration in vitro. A multielectrode probe is used to culture and measure synaptic transmission of a neuronal sample in the presence of various compounds and culturing conditions capable of inducing or protecting against neuronal damage.

Abstract: A method of measuring the physical and chemical properties of tissue or cells and a device for the same is provided, with which the physical and chemical environment of the tissue or cells can be changed arbitrarily corresponding to experimental necessities. The device comprises a system 40 for keeping the physical and chemical environment surrounding the biological tissue or cells constant, a system 50 for arbitrarily changing the physical and chemical environment, observation systems 10 and 20 for observing the physical and chemical properties of the tissue or cells, and a system 30 for comparing the change of the physical and chemical properties of the tissue or cells before and after changing the physical and chemical environment. The observation system 10 is a potential measurement device for measuring the electrophysiological properties of the tissue or cells.

Abstract: This invention relates to methods for the detection and characterization of psychoactives in neuronal tissue by comparing parameters measured for a set of baseline oscillations with those same parameters measured for a set of resulting oscillations. The baseline oscillations are induced or stimulated by such agents as chemical compounds that effect cholinergic interactions, co-deposited neuronal tissue, or electrical stimulations. The resulting set of oscillations is obtained after exposing the neuronal tissue to a sample composition that may or may not contain a psychoactive. By comparing the parameters for the baseline and resulting oscillations, the psychoactive in the sample composition may be detected and characterized as belonging to a specific psychoactive compound class and in some instances, may be distinguished from other members of the psychoactive compound class.

Abstract: This relates to methods for the detection of psychoactive compounds in an in vitro neuronal tissue sample by detecting oscillations of extracellular voltage desirably before and after the introduction of a candidate sample onto an in vitro neuronal tissue sample and for devices useful in practicing the methods. Analysis of the extracellular voltage parameters leads to indication of the presence of psychoactive material in the candidate sample and information as to its pharmacological activity and/or composition. Further, it relates to a process of initiating and maintaining the presence of repetitive neuronal activity within the in vitro sample. Additionally, this includes a method for the stimulation of or initiation of repetitive neuronal activity, e.g.

Abstract: A method of observing a physical and chemical property of a tissue or cell by using an apparatus which comprises at least a cell culturing means, an environment conditioning means, an observing means and a comparing means, comprising the steps of (A) culturing the tissue or cell by the cell culturing means, (B) maintaining a first physical and chemical environment around the tissue or cell by the cell culturing means, (C) observing a first physical and chemical property of the tissue or cell in the first physical and chemical environment by the observing means, (D) changing the first physical and chemical environment to a second physical and chemical environment by the environment conditioning means, (E) observing a second physical and chemical property of the tissue or cell in the second physical and chemical environment by the observing means, and (F) comparing the first physical and chemical property of the tissue or cell with the second physical and chemical property of the tissue or cell by the comparing

Abstract: A two-dimensional sensor is described including a substrate having a Si layer, a SiO2 layer and a Si3N4 layer. On the surface of the Si back side, a thin film is formed by vapor deposition for making an effect electrode. On the surface of the Si3N4 front side, a fence is attached for containing a sample cell, culture medium and a reference electrode. This sensor is placed in an incubator and a bias voltage is applied between the effect and reference electrodes. When a high frequency modulated laser beam irradiates a spot on the back side of the sensor substrate, a signal of AC photocurrent is obtained from the effect electrode. This signal corresponds to a potential alteration due to the cell activity substantially at the spot. The signal is processed in a computer. Therefore, the beam spot size and location, corresponding to the size and the location of the measurement electrode, can be adjusted easily by focusing or moving the laser beam.

Abstract: A two-dimensional sensor includes a photoconductive layer whose conductivity increases at a light-irradiated spot, an insulating layer formed on the front surface of the photoconductive layer, an effect electrode formed on the back surface of the photoconductive layer, and a fence as a cell holder attached to the surface of the insulating layer for containing a cell, culture medium and a reference electrode. The sensor is placed in an incubator and a bias voltage is applied between the effect and reference electrodes. When a laser beam irradiates a spot of the back surface of the sensor, a signal is obtained from the effect electrode. This signal corresponds to a potential alteration due to the cell activity substantially at the laser-irradiated spot. The signal is processed in a computer. The beam spot size and location, corresponding to the size and the location of the measurement electrode, can be changed or adjusted easily by focusing or moving the laser beam.

Abstract: A planar electrode which enables multi-point simultaneous stimulation and recording of nerve cells over a long time is provided, which also has excellent response property. An ITO film is evaporated on the whole surface of an insulating substrate of the hard glass, and the ITO film is etched so that the central portion of each electrode is located on each intersection of 8.times.8 lattices, the center-to-center distances of nearest electrodes of each electrode are equal, and a lead wire is stretched radially. Then, for an insulating layer, negative photo-sensitive polyimide is spin-coated, and an insulating layer pattern is exposure-formed so that a 50 .mu.ms square hole is produced at the center of each electrode. Furthermore, to the exposed portion of each electrode (that is, the inside of the 50 .mu.ms square), Ni is evaporated in a film thickness of 500 nm, which is followed by evaporating gold (50 nm) and platinum black (about 1 .mu.m).

Abstract: This invention relates to a low impedance cell potential measuring electrode assembly typically having a number of microelectrodes on an insulating substrate and having a wall enclosing the region including the microelectrodes. The device is capable of measuring electrophysiological activities of a monitored sample using the microelectrodes while cultivating those cells or tissues in the in the region of the microelectrodes. The invention utilizes independent reference electrodes to lower the impedance of the overall system and to therefore lower the noise often inherent in the measured data. Optimally the microelectrodes are enclosed by a physical wall used for controlling the atmosphere around the monitored sample.

Abstract: A planar electrode which enables multi-point simultaneous stimulation and recording of nerve cells over a long time is provided, which also has excellent response property. An ITO film is evaporated on the whole surface of an insulating substrate of the hard glass, and the ITO film is etched so that the central portion of each electrode is located on each intersection of 8.times.8 lattices, the center-to-center distances of nearest electrodes of each electrode are equal, and a lead wire is stretched radially. Then, for an insulating layer, negative photo-sensitive polyimide is spin-coated, and an insulating layer pattern is exposure-formed so that a 50 .mu.ms square hole is produced at the center of each electrode. Furthermore, to the exposed portion of each electrode (that is, the inside of the 50 .mu.ms square), Ni is evaporated in a film thickness of 500 nm, which is followed by evaporating gold (50 nm) and platinum black (about 1 .mu.m ).

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.

Abstract: A N-(4-aminobutyl)amphetamine-protein complex has been synthesized to be used as an immunogen to prepare an antibody having a higher affinity to methamphetamine that to the hapten N-(4-aminobutyl)amphetamine. The antibody prepared by the use of the complex has 1,000 times the affinity to methamphetamine as that of an antibody prepeared by the use of N-(4-aminobutyl)methamphetamine-protein complex as an immunogen.

Abstract: A N-(4-aminobutyl)amphetamine-protein complex has been synthesized to be used as an immunogen to prepare an antibody having a high affinity to methamphetamine. The antibody prepared by the use of the complex has 1,000 times the affinity to methamphetamine as that of an antibody prepared by the use of N-(4-aminobutyl)methamphetamine-protein complex as an immunogen.

Abstract: This invention relates to a low impedance cell potential measuring electrode assembly typically having a number of microelectrodes on an insulating substrate and having a wall enclosing the region including the microelectrodes. The device is capable of measuring electrophysiological activities of a monitored sample using the microelectrodes while cultivating those cells or tissues in the in the region of the microelectrodes. The invention utilizes independent reference electrodes to lower the impedance of the overall system and to therefore lower the noise often inherent in the measured data. Optimally the microelectrodes are enclosed by a physical wall used for controlling the atmosphere around the monitored sample.

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.

Abstract: A cell potential measurement apparatus, which uses a planar electrode enabling a multi-point simultaneous measurement of potential change arising from cell activities, is provided which can conduct measurements accurately and efficiently as well as can improve convenience of arranging measurement results.