Variety Of Response Patterns Research Articles

Dose effects of morphine on the spontaneous unit activity recorded from the thalamus, hypothalamus, septum, hippocampus, reticular formation, central gray, and caudate nucleus.

Spontaneous activity was recorded from 652 units in 8 subcortical structures of unanesthetized rats. Recordings were obtained in central gray, mesencephalic reticular formation, parafasciculus thalami, caudate nucleus, anterior and ventromedial hypothalamus, lateral septum, and dorsal hippocampus. Eighty recordings were obtained from untreated animals and 80 from saline-injected controls, none of which showed any significant changes of unit activity during the 4- 5-hr observation period. The effect of morphine, given in 5 incremental doses from 0.5 to 30.0 mg/kg ip, was followed in 492 units. Morphine enhanced or depressed spontaneous discharge rates, or caused biphasic effects, ie enhancement alternating with depression and vice versa. Naloxone induced increase in firing after either effect of morphine, or reduced spontaneous activity after morphine-induced increases. However, when morphine reduced neuronal discharges, naloxone never caused further depression. In 86 units, morphine at any dosage failed to alter neuronal activity, but in 54 of these units naloxone nevertheless induced alterations in firing rates. The pattern of responses to morphine differed between all 8 brain regions examined and was characteristic for each individual structure. This is the first systematic study describing the dose-response characteristics of morphine in 8 brain sites recorded simultaneously. Furthermore, it utilized freely behaving animals without the interference of anesthetics, which are themselves known to interact with opiates. The variety of response patterns seen supports the neuropharmacological evidence for multiple opiate receptors or multiple sites of opiate action.

Responses to coloured patterns in the macaque lateral geniculate nucleus: pattern processing in single neurones.

Cell responses to complex visual patterns such as compositions of broad-band (non-monochromatic) colour areas are presented. Patterns were scanned over the receptive field, and cell response at each point was recorded. "Response patterns" were constructed which display the cell transform of the stimulus pattern. Parvocellular layer (PCL) cells in the lateral geniculate nucleus, in a very sustained fashion, signal the spectral composition of areas in the pattern, cells of different classes showing different spectral responsiveness. Little or no edge enhancement was present. Magnocellular layer (MCL) cells mark luminance steps in a pattern; they are not colour-specific. Responses to monochromatic stimuli provided a reliable guide to cell responsiveness with mixed colours. However, integration by spectrally opponent mechanisms is present with broad-band colour stimulation and partly accounts for a high variability of response patterns within the same cell class. With some cells, stimulus patterns were either shown through narrow-band colour filters, or a monochromatic background was added. Response patterns to isolated wavelength components compared with those to full colour patterns revealed an almost linear additivity of individual spectral components. Adaptation to a chromatic background, on the other hand, strongly modified the effectiveness of excitatory and suppressive components in the stimulus pattern and markedly changed the structure of a response pattern compared with the non-adapted situation.

Multiparametric evaluation of the toxic responses of normal human cells treated in vitro with different classes of environmental toxicants.

Eight compounds representing three classes of chemicals were evaluated for their toxic effects on normal neonatal human foreskin fibroblasts in vitro. A battery of toxicity assays was employed to measure the effects of the chemicals on cell viability, DNA synthesis, protein synthesis, DNA repair synthesis, cell ultrastructure, membrane-bound and soluble cytoplasmic proteins, and the activities of six enzymes: beta-glucuronidase, acid phosphatase, gamma-glutamyl transpeptidase, alkaline phosphatase, 5'mononucleotidase, and calcium-magnesium activated (Na+,K+)-dependent ATPase. The compounds evaluated included two antibiotics, each with a metabolic derivative-sulfamethazine (SMZ) and acetylsulfamethazine (ASZ), and carbadox (CBX) and desoxycarbadox (DCX); two anthelmintics-haloxon (HAL) and sansalid (SAN); and a steroid with a metabolic derivative, 17 alpha-estradiol (17-AE) and 17 alpha-estradiol-17-beta-D-glucoside (AE-G). Compounds with similar biological functions often elicited different patterns of response in the normal fibroblasts. For example, the two anthelmintics, HAL and SAN, were similar to each other in that they induced 50% relative cloning efficiencies (EC50) at approximately the same concentrations (HAL = 52 microgram/ml, SAN = 58 microgram/ml), and neither inhibited protein synthesis. They differed, however, in their effects of DNA synthesis. SAN did not inhibit DAN synthesis, while HAL was a profound inhibitor of DNA synthesis (98% inhibition after 4 h at 100 microgram/ml). Because the various toxicants elicited such a variety of response patterns as measured by a multiplicity of parameters, we conclude that similarities in survival responses of cells to closely related toxicants may arise frequently through toxic action at different sites within the cells.

Widening Choices in Motherhood of The Future

The new biomedical techniques of reproduction either currently available or being researched, such as sex predetermination of offspring, sperm banking, test tube conception with embryo transplant, development of artificial wombs and human cloning, allow greatly expanded choices in methods of procreation. A survey of attitudes among 2,138 adults, most of whom are in the early to middle stages of reproductive decision making, shows varying levels of acceptance towards the use of such techniques and towards priority values they would assign to ongoing research to perfect specific technologies. Male-female variation in response patterns are analyzed along with racial and religious differences. Possible and probable impacts that widespread use of these new alternatives might have on the future of women in particular and on various aspects of society in general are discussed.

Acquisition and Retention of Response Patterns in Compound Classical Conditioning

The acquisition and long-term retention of overt response patterns were recorded during compound conditioning with mice. A 10-sec light + tone compound was terminated by a food pellet unconditioned stimulus, with the subject’s relative location tracked by computer during control and stimulus intervals. Compound conditioning elicited a variety of response patterns, including uniformly brief orienting responses to the localized light and tone intermixed with variable duration responses to the food cup. The response patterns resulted in both a complementary inhibition and a sequential dependence between responses that remained relatively stable for 120 to 180 days following initial conditioning. The compound conditioned stimuli elicited a molecular or within-trial “overshadowing” effect, with food cup responses differentially dependent upon the prior occurrence of orienting responses to either the light or tone. Both the concurrent inhibition and sequential elicitation of responses in Pavlovian conditioning are consistent with previous analyses of response patterns in experimental schedules.

A pediatric residency program revisited.

There have been few assessments of residency programs by graduates; therefore, to investigate a practical means of evaluating programs we asked former trainees to relate aspects of their training to present professional needs. Former residents in the Duke pediatric program from 1960 to 1972 were asked to evaluate various aspects of their training. The overall training program was rated favorably, as were most deficiencies were identified in ambulatory pediatric care, such as surgery, dermatology, psychiatry, and radiology. Analysis according to respondent's period of participation in the program and current professional activity revealed little variation in patterns of response. This survey method provides an inexpensive means of monitoring inadequacies in residency programs and provides data to initiate changes.

AN INFLUMZA SIMULATION MODEL FOR IMMUNIZATION STUDIES

A stochastic simulation epidemic model based on discrete time intervals and appropriate for any infectious agent spread by person-to-person contacts is presented. The population is highly structured, allowing for five age groups and for subgrouping mixing in families, neighborhoods, schools, and preschool playgroups as well as total community mixing. With proper choice of relative susceptibility by age, length of latency and infectivity periods, pathogenicity and withdrawal patterns, and the relative infectiousness of silent infections, the model becomes highly agent-specific. The model includes flexible immunization routines and variable vaccine response patterns. The model is applied to the 1957 Asian and 1968 Hong Kong pandemic strains of influenza A. The results of several schedules of immunization of school children are presented and compared for the two strains.

An electronic activity integrator for operant conditioning of patterns of neural and muscular activity

An activity integrator circuit designed to detect and operantly reinforce patterns of neural and muscular activity is described. An integrator voltage proportional to the weighted sum of multiple input signals reaches a threshold level when the requisite response pattern is emitted. A variety of response patterns may be differentially reinforced, depending on the nature of the integrated signals.

An analysis of response patterns for conditional reasoning schemes

One hundred and ten college Ss assessed the truth of the conclusions for 40 conditional reasoning items. These items varied according to principles of inference and validity status. The results indicated some interesting intra- and interrule variations in response patterns.

Behavior in a complex learning situation involving five stimulus-differentiated paths

Six male albino rats were tested daily for 39 days on a five-choice multiple path elimination problem in which paths were differentially covered (by sandpaper, burlap, velure, etc.) and in which the order of elimination was not controlled in any way by the E. All Ss solved the problem, attaining the criterion much more rapidly than a parallel group had achieved such solution with uniformly surfaced wood paths. Variation in patterns of response on successive trials was characteristic of Ss while they maintained high accuracy. Strong preferences were displayed for selecting, on successive runs, paths that diverged maximally from each other.

Responses of cat pallidal neurons to cortical and subcortical stimuli

Discharge patterns of pallidal neurons of the cat were studied during single-shock and sustained high-frequency stimulation of sensorimotor cortex (SMC), caudate nucleus, nonspecific thalamic nuclei (CM), subthalamus, midbrain reticular formation (MRF) and amygdaloid complex. Three types of spontaneous discharge pattern were found in pallidal neurons: high discharge rate (HDR), low discharge rate (LDR) and repetitive burst patterns were observed. The LDR and repetitively discharging units generally responded to a limited number of the stimulus sites, occasionally to one site exclusively, whereas HDR units generally showed a high degree of convergence. The response patterns of units responding to single-shock stimulation of MRF, CM, and subthalamus were similar. A marked facilitation lasting 20–50 msec was a consistent response which in some units was followed by a prolonged facilitation or inhibition. Sustained high-frequency stimulation always resulted in a net facilitatory effect. Single-shock stimulation of caudate nucleus and SMC generally produced a powerful inhibition. In some units facilitation preceded this inhibition, and in a small number of units, only facilitation was observed. Sustained high-frequency stimulation produced either inhibitory or facilitatory effects. Single-shock stimulation applied to amygdala caused an initial facilitation, followed in some units by inhibition or facilitation. High-frequency stimulation produced either facilitatory or inhibitory effects. The variation in response patterns to stimulation of each stimulus site was dependent upon the individual neuron and not upon the stimulus site. Analyses of the responses to a test stimulus following a conditioning stimulus suggest that the excitability changes of the neuron following single-shock stimulation are well represented by the poststimulus time histogram.

The effects of periodic challenge on the response of alpha-2-AP globulin and other acute-phase reactants of rat serum to tissue injury.

The effects of periodic challenge with turpentine on the concentration of the acute-phase reactants of serum were studied in young, adult, male Sprague–Dawley rats. The initial injection of the phlogogenic agent was followed by rapid and significant increases in the concentrations of plasma fibrinogen, total serum glycoprotein, serum complement, and the α2-AP globulin and seromucoid fractions. Variable response patterns were observed on subsequent challenges and in the intervals between. The conclusion was drawn that the acute-phase reactants of serum do not respond in a uniform manner to repeated challenge with a phlogogenic agent, and by inference their synthesis must be regulated by several different mechanisms.

Editorial Comments: As we read

The titles in this issue run the usual gamut, but most of them deal in one way or another with one of the major features of modern mathematics teaching. As you read, note how one particular question of methodology keeps coming up. It is the matter of the teacher recognizing and encouraging a variety of response patterns. Sometimes it is suggested outright as a criticism of the teacher depending too much on memorized responses— verbalisms, if you please. Other times it is more subtle—the mere suggestion that a line of questioning or a series of activities will lead to a desired response.