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Biomedical subjects

R D Fitzgerald

Publications and source records attributed to R D Fitzgerald.

At least 55 records · Page 3Linked to original sources

Pavlovian conditioning with ethanol and lithium: effects on heart rate and taste aversion in rats.

Rats received paired injections of either ethanol or saline as the conditioned stimulus and lithium chloride as the unconditioned stimulus (US) in a Pavlovian differential conditioning paradigm. Lithium chloride evoked a large deceleration in heart rate (80-100 beats per minute) as an unconditioned response. As a result of 10 conditioning trials, the substance paired with LiCl elicited a lower average heart rate than that elicited by the unpaired substance. Moreover, animals that received ethanol-LiCl injections subsequently were more averse to the taste of ethanol than animals receiving saline-LiCl pairings. However, there were no differences in ethanol's ability to serve as the US to induce an aversion to a novel flavor solution (i.e., the Avfail phenomenon was not observed). The overall pattern of results underscores the value of using multiple indexes of learning in drug-drug conditioning paradigms.

Animals↗

Effects of restriction of maternal uterine blood supply on postnatal conditioning of heart rate and behavioral development in dogs.

An examination was made of the heart rate responses during aversive classical conditioning of 5- to 6-week-old Labrador puppies exposed to restricted maternal uterine blood supply during gestation. The direction of the heart rate responses of the treated puppies was consistently decelerative, whereas nontreated controls showed both decelerations and accelerations. The absence of accelerative heart rate changes, combined with the observed depression of base level heart rate and attenuated emotional behavior in the experimental animals relative to controls suggests that uterine blood supply insufficiency may have impaired normal autonomic development in utero.

Animals↗

Autonomic control of heart rate and blood pressure in spontaneously hypertensive rats during aversive classical conditioning.

An examination was made of the heart rate (HR) and blood pressure (BP) responses of 7-9-wk-old spontaneously hypertensive rats (SHR) and genetical control Wistar/Kyoto (WKY) rats during aversive classical conditioning. Subsequent to the development of conditioned responding (CRs), assessments were made of the effects of selective autonomic blockade by methyl atropine (10 mg/kg), phentolamine (2 mg/kg), and propranolol (2 mg/kg). The CR complex in the two strains consisted of pressor BP CRs in conjunction with vagally mediated decelerative HR CRs in the SHR strain and sympathetically mediated accelerative HR CRs in the WKY strain. The decelerative SHR HR CR did not appear to be secondary to baroreceptor reflex activity, although such activity did appear to be involved in the pressor BP and decelerative HR orienting response (OR) and unconditioned response (UR) complex of the SHRs on the initial application of the CS and the US, respectively. Augmented pressor BP ORs, CRs, and URs in the SHRs relative to the WKYs and differential drug effects on BP and HR baselines of the two strains suggested the presence of enhanced sympathetic activity in the SHRs that was not reflected in the SHR decelerative HR CR. Phentolamine unmasked evidence of reflex beta 2-vasodilation deficiency in the SHRs that could have contributed to the enhancement of their BP OR and CR.

Animals↗

Group process in teaching family dynamics to family practice residents.

Behavioral science training in family practice at Madigan Army Medical Center, Tacoma, Washington, has used small group seminars to teach family dynamics on an experiential level. The group process is similar enough to dynamics within families to facilitate understanding by introspection. Small groups are an efficient method for teaching, and allow experiential learning to occur spontaneously as well as on a planned basis.

Family↗