PubMed Health⌕ Search

Biomedical subjects

A L Riley

Publications and source records attributed to A L Riley.

At least 55 records · Page 3Linked to original sources
PubMed1984

Opiate withdrawal: the result of conditioning or physiological mechanisms?

Although it has been suggested that opiate withdrawal responses might be conditioned compensatory responses elicited by drug-associated stimuli, the present results do not support such a view. Withdrawal, as measured by an aversion to a saccharin solution following the termination of morphine administration, occurred independent of the presence of morphine-paired environmental or temporal cues. These results suggest that withdrawal is most likely the result of some physiological mechanism, rather than the result of conditioning.

Animals↗
PubMed1984

The effects of LiCl preexposure on amphetamine-induced taste aversions: an assessment of blocking.

Preexposure to lithium chloride attenuated the subsequent acquisition of amphetamine-induced taste aversions. This attenuation was independent of the similarity of the preexposure and conditioning environments, an effect inconsistent with an associative interpretation of the effects of LiCl preexposure. These results were discussed in terms of the mechanism underlying the effects of drug preexposure on taste aversion learning.

Amphetamine↗
PubMed1984

The effects of trimethyltin chloride on the acquisition of long delay conditioned taste aversion learning in the rat.

Naive rats injected with LiCl at various times following consumption of a novel saccharin solution subsequently avoided the ingestion of saccharin with the degree of the aversion related to the interval between ingestion and LiCl administration. Although a similar relationship was also evident in animals which had received a single intragastric administration of trimethyltin chloride 21 days prior to the pairing of saccharin and LiCl, the trimethyltin-pretreated subjects receiving delayed injections of LiCl displayed weaker taste aversions than those not exposed to trimethyltin. This disruption in the acquisition of taste aversions over long delays is consistent with other work suggesting that trimethyltin disrupts tasks involving short-term memory. The utility of the conditioned taste aversion paradigm in detecting and characterizing drug toxicity was discussed.

Animals↗
PubMed1981

The effect of post-conditioning exposure to morphine on the retention of a morphine-induced conditioned taste aversion.

In the following experiment, multiple injections of morphine sulfate following the acquisition of a morphine-induced taste aversion had no effect on the retention of the previously acquired aversion. Post-conditioning injections of morphine resulted in the development of physical dependence to morphine and led to a decrement in the ability of morphine to induce a subsequent aversion to a second novel taste. This failure of post-conditioning exposures to morphine to affect a previously acquired morphine-induced taste aversion even though tolerance to morphine had occurred was discussed in the context of Rescorla's event-memory model of conditioning.

Animals↗
PubMed1981

Effect of listeners' comprehension on judgments of speakers' height and weight.

To determine the effect of listener's comprehension on speakers' height and weight judgments, a total of 40 speakers, 20 Americans (10 females and 10 males) and 20 non-Americans representing various nationalities (10 females and 10 males), recorded a standard prose passage. A total of three master tapes were constructed to represent the three experimental conditions: (1) American speakers' readings in English, (2) foreign speakers' reading in their native languages, and (3) foreign speakers' readings in English. A total of 30 judges, 15 females and 15 males, participated in three sessions, one for each of the three master tapes, and were asked to provide direct estimations of the height and weight of each speaker from the tapes. Listeners' comprehension does not appear to play a major role in height and weight judgmental tasks.

Adult↗
PubMed1980

Total avoidance of saccharin consumption by rats after repeatedly paired injections of ethanol or LiCl.

Rats injected with ethanol or LiCl following consumption of novel saccharin solution drank less saccharin than non-poisoned controls on a subsequent exposure with degree of aversion positively related to dose of ethanol (2--5 g/kg). While a single pairing of saccharin with ethanol or LiCl resulted in partial avoidance of saccharin solution, repeated conditioning trials led to total avoidance of saccharin consumption by animals injected with the higher doses of ethanol or with LiCl. These results, characteristic of emetic-induced aversions, support the explanation of the limited consumption of ethanol by rats under ad lib, free-choice conditions as a result of acquired aversion to the oronasal sensory stimuli of ethanol after association with pharmacologically aversive aftereffects of consumed ethanol.

Animals↗
PubMed1980

The role of endorphins in animal learning and behavior.

The present review examined the influence of endorphins in animal learning and behavior. It was suggested that in learning paradigms involving stress, the stressor elicits the release of endorphins. Given the evidence on endorphin-mediated, stress-induced analgesia, it was further suggested that the stress-induced release of endorphins modulates the aversiveness of the stressor, and as such, affects the learning based on this stressor. A number of learning paradigms, e.g., the conditioned emotional response, preference for signaled shock, conditioned taste aversions, and learned helplessness, were presented in support of this mediation of learning by the endorphins. A possible interaction between the endorphins and adrenocorticotropic hormone was offered as a physiological basis for this mediation.

Adrenocorticotropic Hormone↗
PubMed1978

Effect of prolactin on glomerular filtration rate.

1. The effect of infusion of ovine prolactin was studied in anaesthetized dogs pretreated with bromocryptine to reduce the release of endogenous prolactin. 2. Prolactin, injected intravenously and also directly into one kidney, resulted in a 12--18% increase in glomerular filtration rate (GFR) by both kidneys. 3. This increased GFR was not associated with any demonstrable changes in whole-kidney blood flow, distribution of intrarenal blood flow, fractional excretion of sodium or osmolar or free-water clearance. 4. We conclude that ovine prolactin produced an increase in GFR not dependent on an increase in whole-kidney plasma flow.

Animals↗
PubMed1978

Effect of ischemia on renal blood flow in the rat.

The effect of ischemia on renal blood flow (RBF) in the rat has been an unsettled question. This study used a totally extractable indicator, radioactive microspheres, with a reference arterial sample, to study RBF quantitatively 10 and 60 min after 1 h of unilateral renal artery clamping in anesthetized, heparinized rats. The results indicate that after release of the arterial clamp, the kidney is enlarged and exhibits an increase in renal vascular resistance. RBF to the contralateral non-ischemic kidney is not different from that of a time-control series.

Animals↗
PubMed1977

Renal proximal tubular dysfunction and paroxysmal nocturnal hemoglobinuria.

A patient with paroxysmal nocturnal hemoglobinuria, who required many blood transfusions for hemolytic episodes, had a persistent hyperchloremic metabolic acidosis. Bicarbonate infusion demonstrated a large fractional excretion of bicarbonate (28.6 per cent at a plasma bicarbonate level of 23 meq/liter) which was consistent with proximal renal tubular acidosis. Generalized aminoaciduria and decreased tubular reabsorption of phosphate were also present. Marked deposition of iron in renal proximal tubules was associated with these functional abnormalities. We believe that, as systemic acidosis can promote hemolysis in patients with paroxysmal nocturnal hemoglobinuria, hemolysis can lead, by way of iron deposition in renal tubules, to further acidosis. This cycle should be interrupted with appropriate doses of bicarbonate.

Acidosis, Renal Tubular↗
PubMed1976

Drug exposure and the acquisition and retention of a conditioned taste aversion.

Two experiments examined the effects of preexposure and postexposure to a drug on the acquisition and retention of a conditioned taste aversion induced by that drug. Experiment 1 demonstrated that although drug preexposure attenuated a subsequent conditioned aversion, repeated taste-drug pairings reversed the initial attenuation effect and resulted in nearly complete avoidance of consumption. Experiment 2, however, demonstrated that drug postexposure did not alter a previously established conditioned aversion, although the postexposure experiences were effective in attenuating a conditioned aversion to a second novel solution. It was suggested that conditioned aversions are mediated by ACTH and that preexposure to a drug results in tolerance to that drug, yielding a smaller ACTH response and thereby a weaker aversion.

Animals↗