A multipurpose activity platform utilized in the open-field setting

An automated multipurpose activity platform (MAP) that can be used to measure activity in the horizontal plane is described. Detection of the position of a small-bodied animal is based on completion of an electronic circuit in one or several cells of a 21 by 21 matrix below the floor. The MAP is constructed on the basis of an 11 by 11 matrix, but, through electronic averaging, operates functionally on the basis of a 21 by 21 matrix. The MAP has no built-in data storage facility and needs to be interfaced with a recording system. The system has been successfully utilized in measuring open-field activity of the rats.     

A system for automatic recording and analysis of motor activity in rats

We describe the design and evaluation of an electronic system for the automatic recording of motor activity in rats. The device continually locates the position of a rat inside a transparent acrylic cube (50 cm/side) with infrared sensors arranged on its walls so as to correspond to the x-, y-, and z-axes. The system is governed by two microcontrollers. The raw data are saved in a text file within a secure digital memory card, and offline analyses are performed with a library of programs that automatically compute several parameters based on the sequence of coordinates and the time of occurrence of each movement. Four analyses can be made at specified time intervals: traveled distance (cm), movement speed (cm/s), time spent in vertical exploration (s), and thigmotaxis (%). In addition, three analyses are made for the total duration of the experiment: time spent at each x–y coordinate pair (min), time spent on vertical exploration at each x–y coordinate pair (s), and frequency distribution of vertical exploration episodes of distinct durations. User profiles of frequently analyzed parameters may be created and saved for future experimental analyses, thus obtaining a full set of analyses for a group of rats in a short time. The performance of the developed system was assessed by recording the spontaneous motor activity of six rats, while their behaviors were simultaneously videotaped for manual analysis by two trained observers. A high and significant correlation was found between the values measured by the electronic system and by the observers.     

A system for recording family sessions

A diagrammatic technique for recording family sessions is presented. The Interaction Chronogram is a visual display system originally devised for use in group psychotherapy by Cox, but can be modified for work with families. The system permits a family session to be summarized diagrammatically and aids review of a family's treatment. A 'diagnostic' and treatment session with one family is presented to illustrate the system's use.     

Effects of intrahippocampal injections of the cholinergic neurotoxin AF64A on open-field activity and avoidance learning in the rat

The effects of direct intrahippocampal administration of the cholinergic neurotoxin, AF64A, were investigated in male rats. Bilateral injections of AF64A (5 nmole/2 microliters) produced a significant decrease in choline acetyltransferase (CAT) activity in the dorsal hippocampus (25%) and overlying frontoparietal cortex (30%) but no changes in the striatum. Rats lesioned with AF64A exhibited increased levels of open-field activity, which was most marked at 1 week after the lesion; however, the rates of intrasession habituation were similar in lesioned and control rats. Lesioned rats also displayed deficits in acquisition and retention of a passive avoidance task and less dramatic deficits in acquisition of two-way shuttle box avoidance. These findings indicate that lesioning of cholinergic terminals in the hippocampus and/or cerebral cortex with AF64A leads to long-term deficits in learning and memory as well as increases in open-field activity.     

A fiber-optic system for recording skin conductance in the MRI scanner

The acquisition of the skin conductance response (SCR) during functional magnetic resonance imaging (fMRI) raises significant safety issues, as well as practical ones, which need to be addressed in order for these experiments to be conducted safely and successfully. Metallic and conductive wires in the presence of time-varying gradient magnetic fields such as those present in fMRI experiments may induce heating, as well as electric fields, in these components and, if in contact with the subject, could produce severe burns and electric shocks. Moreover, these metallic and conductive components can significantly distort the magnetic field, resulting in image artifacts. A system for recording the SCR in humans simultaneously with fMRI is presented. The device is a fiber-optic-based transducer, which records the SCR from two fingers of the same hand, using electrodes containing inline radio frequency (RF) suppression filters and protective resistive loads. The fiber-optic SCR transducer was tested using 1.5 and 3.0 Tesla MRI scanners running EPI sequences. This system was able to safely record SCRs free of RF interference during an fMRI experiment, and the fiber-optic design of the transducer eliminated any artifacts on the MRI scan.     

A portable four-channel cassette recording system for short-term electroencephalogram in the field

A portable four-channel electroencephalogram (EEG) cassette recording system has been designed which offers good performance, is simple to construct, and moderate in cost. The recorder is compatible with a commercially available, portable, battery-operated power source, and is therefore usable in the field where line power is unavailable. The system incorporates a small, lightweight, portable, battery-powered oscilloscope which provides monitoring and playback capability. While a few experimental portable EEG recorders have been reported in recent years with more channel capacity or perhaps lighter weight, the engineering details of these units are rarely published and, in any event, would require a substantial effort for most electronics support shops to reproduce. The recording system described here, however, should be within the capability of most electronics support groups to assemble in a very short time and provide good performance.     

A computer-oriented system for high-speed recording of operant behavior

A method is described by which large quantities of data, generated at high and variable rates from a large number of test boxes, are recorded on a single eight-channel punched paper tape. The data, which include a record of the occurrence time of each event in 1/10-sec units, are in a compact form, suitable for conversion to standard Hollerith punched card codes and for decoding and summarizing by a large digital computer. Experience with the system has demonstrated a high degree of accuracy and reliability, and low operating cost.     

A three-electrode system for EKG recording and aversive shock

The use of three electrodes to produce digitizable EKG’s and to deliver shocks to the tail of the monkey is described. Cardiac signals are taken from a head electrode and a “ground” tail electrode. Shock is administered through a “hot” tail electrode and the “ground” tail electrode.     

A technique for chronic recording of systemic arterial blood pressure in the unrestrained rat

A technique is described for the chronic recording of systematic arterial blood pressure, respiration, and heart rate in the unrestrained rat. The surgical implantation and anchoring procedures described are compatible with the delivery of noxious electric shock and/or rewarding intracranial brain stimulation as reinforcement. Data on catheter patency are analyzed in 65 rats participating in a variety of experiments on the instrumental and classical conditioning of blood pressure responses. The results indicate that it is difficult to maintain satisfactory catheter performance beyond 2 weeks.     

A simple method for recording the path of a rat in an open field

A method for recording the path of a rat during exploration or during a search task in an open field is presented. Its principle relies on the monitoring of the center of gravity of the rat. The open field lies on three strain gauges, on which output signals are sampled at a certain frequency by a digital acquisition system while the rat is walking on the platform. The discrete path is reconstructed off line, and several representative parameters are calculated. Some illustrative results are given.     

A durable recording and feedback system

A durable low-cost data-recording and feedback system is described. Data transcribed with a special pen onto a plastic sheet can be removed only with two solvents. These data can be displayed for feedback purposes without fear of destruction.     

A system for recording individualized behavioral data in a token program

A data matrix system used to record and summarize individual behavioral data is described. The major characteristics of the system are: (1) it provides a place to record and summarize all patient token exchanges, whether for standard contingencies or for idiosyncratic behavior; (2) it serves as a record and summary for time samples observed during a 24-hr period and as a record of reliability data on time sample measures; (3) it provides a place where the new token balance for each patient can be calculated and recorded for use the next day; (4) it provides for calculation of an individual patient's token balance at any given moment; and (5) it is a permanent record of each patient's daily participation in the program and documents progress in terms of his economic status as well as in changes in critical target behaviors.     

A digital system for recording startle,responses in small animals

An easily constructed, isometric startle-recording system is described. The animal enclosure is attached to a plywood board-which, in ten, is mounted in a “springboard” arrangement. Movement is detected by a phonocartridge mounted beneath the chamber, and a digital record of this movement is obtained through the use of a voltage-to-frequency converter. A brief experiment in which the system was used to assess the rat’s reaction to electric footshock is also presented.     

A minicomputer system for recording the dynamic properties of individual operant responses

A PDP-12 is used to conduct operant experiments in which peak force, duration, time integral of force, and interresponse time may each serve as the criterion response property for reinforcement, and all four properties are simultaneously recorded as dependent variables. Calibration, acquisition and control, and data analysis programs are described.