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Some neurobiological applications of the BBC Model B microcomputer and Unilab 8-bit interface.

Four computer programs written for the BBC Model B microcomputer (coupled to a Unilab 8-bit interface) are discussed. These programs enable the system to be used as (1) a transient recorder, (2) a rapid signal averager, (3) a spike-train analyser and (4) an instrument for measuring the amplitude of single channel currents. Flow-charts illustrating the operation of each program are given along with a detailed discussion of how the programs may be used in the laboratory. The discussion is illustrated using recordings taken from experiments conducted on a range of neurobiological preparations.

Animals↗

Implementation of a movement paradigm using the Commodore 64 microcomputer.

Implementation of an alternating movement paradigm for monkeys was achieved using an inexpensive but versatile microcomputer, the Commodore 64. During task performance, the computer monitors one of three user selectable input signals (e.g. joint position) and continuously displays this signal as a moving cursor on a video monitor along with a user positioned target box. Other user defined parameters include in-target holding time and reinforcement ratio. The system also provides two sound cues to signal entry of the cursor into the target box and successful completion of a trial. Extensive use is made of the computer's intrinsic hardware features for implementation of movement paradigm functions. Use of external components is limited to digitizing and interface hardware. A two part software package consisting of a BASIC and a machine language program performs all task and hardware related functions. Acquisition and display of analog input signals, display of target positions, and delivery of auditory cues and applesauce rewards are all controlled by the machine language program. All user defined parameters are specified from the BASIC menu program. The specific programs described in this paper should be applicable to the control of tasks requiring alternation of a behavioral parameter between two target zones.

Animals↗

Microcomputer-assisted densitometer for quantitative receptor autoradiography.

We describe here a simple, inexpensive microcomputer-assisted densitometer for use with quantitative receptor autoradiography. The resolution of this system is approximately 100 micron. With this system, and an accompanying program DENSIT, it is relatively easy to convert density values of autoradiograms into molar quantities of bound ligand. The general design of the system and the logic of the DENSIT program are applicable to a variety of hardware systems.

Animals↗

An inexpensive microcomputer digital imaging system for densitometry: quantitative autoradiography of insulin receptors with 125I and LKB Ultrofilm.

This article describes a video digitizing system designed for measuring film optical density. The system, which is based on a 6-bit (64 gray level) digitizer, solid state video camera, and Apple II microcomputer, digitizes a rectangular area selected by the operator and converts the gray level values into preselected standard units. In order to develop autoradiographic standard curves for quantitative autoradiography with 125I-insulin, liver slices labeled with 125I-insulin and plastic sections containing known amounts of tritium were apposed to the same sheet of LKB Ultrofilm for exposures of 1-7 days. The results indicate that 3H plastic standards can be used to calibrate QAR of 125I-labeled ligands with LKB Ultrofilm. The Apple system was also used to measure binding of 125I-insulin to the external plexiform layer (EPL) in slices of the rat olfactory bulb. Results suggest that the EPL has two binding sites for insulin, a high affinity site with Kd = 1.0 X 10(-8) M and a low affinity site having a Kd = 1.4 X 10(-5) M.

Animals↗

A distributed microcomputer-controlled system for data acquisition and power spectral analysis of EEG.

A relatively powerful and inexpensive microcomputer-based system for the spectral analysis of the EEG is presented. High resolution and speed is achieved with the use of recently available large-scale integrated circuit technology with enhanced functionality (INTEL Math co-processors 8087) which can perform transcendental functions rapidly. The versatility of the system is achieved with a hardware organization that has distributed data acquisition capability performed by the use of a microprocessor-based analog to digital converter with large resident memory (Cyborg ISAAC-2000). Compiled BASIC programs and assembly language subroutines perform on-line or off-line the fast Fourier transform and spectral analysis of the EEG which is stored as soft as well as hard copy. Some results obtained from test application of the entire system in animal studies are presented.

Animals↗

A microcomputer-controlled response measurement and analysis system for insect olfactory receptor neurons.

A microcomputer system has been built to stimulate, record, and analyze responses from peripheral insect olfactory receptor neurons. Software has been developed to sort action potentials (spikes) in extracellular records obtained from multi-innervated antennal sensilla, and perform frequency, interspike interval, distributional, and regression analyses on responses in groups of records. The olfactory stimuli can be presented in different patterns, and plots or histograms of analyses, spike records, and individual spikes can be displayed in different formats and hard-copied during a recording session. This report describes the main features of the system and discusses the methods used for sorting spikes, performing analyses, and managing records and analyses in a database. Examples are given of renewal density analyses for 4 classes of peripheral receptor neuron in records from 2 types of olfactory sensillum on the antenna of the cabbage looper moth, Trichoplusia ni (Hübner).

Action Potentials↗

Video image analysis of behavior by microcomputer: categorization of turning and locomotion after 6-OHDA injection into the substantia nigra.

The automated video image analyzing system (VIAS) measures locomotion in meters and turning behavior of rats by digitized video image and microcomputer evaluation. To measure turning behavior the number of 1/4, 1/2, 3/4 and complete turns are recorded. The turns are classified in different diameter classes. To test the validity of this system rats were administered unilateral 6-OHDA lesions of the substantia nigra and were observed by human rater and VIAS in parallel. Correlation coefficients for the data obtained by both methods were r = 0.98 for locomotion, r = 0.93 for half turns with diameter greater than or equal to 30 cm. Recovery from lesion-induced turning of animals with striatal dopamine depletion of 81.4% to 87.2% was described in detail by VIAS with respect to the diameter of the turns. It is concluded that VIAS provides a potent tool for the analysis of turning behavior and locomotion.

Animals↗

Simple microcomputer system for mapping tissue sections with the light microscope.

We describe a method for two-dimensional mapping of tissue sections that makes use of a drawing tube, microscope stage encoders and a microcomputer. The drawing tube views the graphics monitor and superimposes the image of the screen cursor and on-screen menus on the specimen image. Thus, the position of every landmark in each microscopic field can be mapped without stage movement while directly viewing the specimen through the microscope. A mouse is used for data entry and program control. Fields mapped in this way are then assembled into a complete map, which can include line drawings as well as up to 20 landmark types. The coordinate values of all landmarks mapped are stored and remain accessible for editing and analysis. High resolution plots are produced. Specialized functions include grain counting, area and perimeter calculations as well as a perimeter limiter that predefines the area to be mapped. The system uses general purpose hardware that is widely available. Many hitherto time-consuming tasks, such as detailed mapping of cell positions, regions of immunocytochemical staining, degenerating fibers, neuronal connections or any other anatomical feature, can be done in a fraction of the time and effort previously involved. These labor savings can be realized while maintaining the highest resolution and enabling statistical analysis since the data are already in digital form.

Animals↗

Real-time spectral intensity analysis of the EEG on a common microcomputer.

An inexpensive system for quantitative electroencephalogram (EEG) analysis over long time periods is described. This system continuously analyses EEG for intensity versus frequency content, and saves averaged 'data reduced' intensity spectra to disk at regular intervals. The method had adequate frequency resolution for EEG analysis and demonstrated useful data reduction. In the example presented 1 day of sampled EEG data (20 megabytes) were reduced to 125 kilobytes of averaged spectra, thus illustrating the utility of the system for long term EEG studies. The system uses a low cost microcomputer (IBM AT compatible) with data acquisition board and a simple multitasking program developed with Asyst software.

Animals↗

A new precise microcomputer based rotometer.

The rotometer described here consists of a data acquisition system made of several reed relays which are activated by a small moving magnet when the animal performs rotations. The apparatus has an angular discrimination which is dependent on the number of reed relays used. A simple interface is used to normalize the pulses produced when the reed relay contacts are closed. This normalized output closes key contacts in the keyboard of a microcomputer resulting in ASCII strings. A simple BASIC program is used for computation of various turn fractions. The program also calculates the total number of movements over time, allowing the assessment of activity vs. time.

Amphetamines↗

A microcomputer-controlled system for use in auditory physiology.

This report describes a digitally controlled system for use in auditory physiology in which signal generation and data acquisition are under the control of a single microcomputer. The system is designed to generate the complex waveforms required in neuroethological studies, and is able to generate these signals at frequencies of up to 160 kHz with a resolution of 1 Hz. The system is built around a commercially available digital hardware system, and augmented with custom components to enhance operation speed, precision and flexibility.

Hearing↗

An ASSEMBLER routine for on-line graphic display and averaging of data acquired on a personal microcomputer.

An ASSEMBLER routine is described for data acquisition and "on-line" averaging, artefact rejection and graphic display of data on a personal microcomputer (IBM compatible). The user determines the number of input channels, sampling frequency, number of samples, input range, stimulation frequency (epoch frequency) and the number of epochs to be acquired and averaged. Data from each epoch are scanned in search of saturating artefacts and will be added to previous epochs if none is found. Data are then graphically displayed as voltage versus time before acquiring next epoch. Display options can be defined by the user at run time by means of the keyboard and include: display of last epoch, display of the average, storage screen and refreshing screen after every epoch. High data transfer rates and program speed allows for high stimulation rates in the presence of on line graphic display. The computer then behaves as a multichannel digital oscilloscope with access to large memory buffers, disk storage, high averaging capabilities, artefact rejection and wide potential for data analysis. Its applications to the recording of magnetic and electric evoked responses are illustrated. The program is available from the authors.

Computer Graphics↗

A microcomputer-based system for real-time analysis of animal movement.

A microcomputer-based video system for tracking, recording, and analyzing the movement of animals in two dimensions on variegated background in real-time has been developed and validated, both mechanically and with moving animals. Hardware and software (donationware) costs are low. Specimens visualized as small as 3 pixels long may be tracked in an arena that is 240 x 320 pixels in size. The results of tracking a mechanical moving spot are compared with a theoretical circular path. Comparisons between frame-by-frame human observation and computer generated X-Y coordinates are also presented. Applications of the tracking system include insect toxicology and pheromone bioassay, vertebrate locomotion studies, and basic research on taxes and kineses.

Animals↗

Microcomputers as aids in Gottschalk-Gleser rating.

Different types of errors during the various steps of Gottschalk-Gleser content analysis of speech samples are discussed. Several attempts have been made in the past to avoid error by using computer programs to categorize verbal material. Although these systems offer the advantage of increasing reliability to a maximum, validity is a problem. More recent approaches, which use artificial intelligence methods of language understanding by computer, show promise. However, these computer systems will have to be further developed before they can perform at the same level as human raters. For this reason, an alternative approach is presented which only relies on computers in a limited way: All steps of Gottschalk-Gleser content analysis are performed with a collection of programs on a small 8-bit microcomputer: transcription, scoring, storage, and computation of scores. The different steps of using this system are described, and it is argued that a significant reduction of error, both random and systematic, can be achieved through this system.

Computers↗

A microcomputer-based system for detailed analysis of rat behavior.

A microcomputer-based system that can measure rotational behavior and moving velocity is described. Infrared photobeams detect the animal behavior. One advantage of this system is that data can be stored on floppy disks and analyzed in arbitrary time intervals. This system may be useful for detailed analysis of rat behavior in physiological or psychopharmacological experiments.

Animals↗

An obstetric microcomputer information system.

A systems analysis has been done to determine how computer technology can provide an information system to improve the care of the mother and her baby. A minimum data base was established complying with the recommendations of the Körner Committee and designed to meet the needs of the health personnel looking after the mother and baby. An ICL DRS 20/50 network of four microcomputers has been installed in the obstetric unit of a district teaching hospital with a link to the regional mainframe. There have been no significant software or hardware faults since the system became fully operational in January 1984. All women are registered on the system at their first visit allowing the pregnancy to be followed prospectively. Subsequently midwives enter data on line at delivery and at discharge. The on line validation and range checks improves the accuracy of the data allowing a reliable perinatal audit to be obtained routinely. The system has been accepted by the staff since much of the routine pregnancy documentation is produced automatically. This includes booking letters and summaries for general practitioners, admission slips, birth notification forms, registers and forms for the community midwives and health visitors. Immediate production of reports for community health staff allows better communication and improved patient care. No additional staff are needed in the obstetric unit and one job which was mainly of a clerical nature has been saved and the salary transferred to provide one more midwife for the postnatal wards.(ABSTRACT TRUNCATED AT 250 WORDS)

Computers↗

A microcomputer-based program for video analysis of chemotaxis under agarose.

We have developed a computerized system for the quantification of video images of cell migration patterns obtained in the chemotaxis under agarose assay. This system allows either manual or automatic measurement of standard parameters of chemotaxis, as well as quantification of three new parameters which reflect mean cell movement and chemokinesis. The parameters of mean cell population movement are not obtainable by the traditional analysis of the chemotaxis under agarose assay. Our system operates on an inexpensive microcomputer, is easy to use and provides data output in a format that is directly transferable to standard statistical packages.

Chemotaxis, Leukocyte↗

Alignment of nucleotide or amino acid sequences on microcomputers, using a modification of Sellers' (1974) algorithm which avoids the need for calculation of the complete distance matrix.

A program to calculate optimum alignment between two sequences, which may be DNA, amino acid or other information, has been written in PASCAL. The Sellers' algorithm for calculating distance between sequences has been modified to reduce its demands on microcomputer memory space by more than half. Gap penalties and mismatch scores are user-adjustable. In 48 K of memory the program aligns sequences up to 170 elements in length; optimum alignment and total distance between a pair of sequences are displayed. The program aligns longer sequences by subdivision of both sequences into corresponding, overlapping sections. Section length and amount of section overlap are user-defined. More importantly, extension of this modification of Sellers' algorithm to align longer sequences, given hardware and compilers/languages capable of using a larger memory space (e.g. 640 K), shows that it is now possible to align, without subdivision, sequences with up to 700 elements each. The increase in computation time for this program with increasing sequence lengths aligned without subdivision is curvilinear, but total times are essentially dependent on hardware/language/compiler combinations. The statistical significance of an alignment is examined with conventional Monte Carlo approaches.

Amino Acid Sequence↗