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Biomedical subjects

K F Killam

Publications and source records attributed to K F Killam.

At least 37 records · Page 2Linked to original sources
PubMed1984

Reinstatement of responding maintained by cocaine or thiamylal.

Rhesus monkeys were trained to self-administer one of two reference drugs, either cocaine or thiamylal. The lowest dose of cocaine or thiamylal which maintained responding was determined. Responding extinguished when saline was substituted for a reference drug. Then the effects of a variety of other drugs on saline self-administration were determined. In the cocaine-trained monkeys, the i.m. administration of d-methylamphetamine, cocaine, morphine or codeine during a session reinstated responding for saline infusions; in contrast, naloxone, chlorpromazine, dimethyltryptamine, diazepam and secobarbital did not. Naloxone blocked responding produced by the i.m. administration of morphine. In the thiamylal-trained monkeys, the administration of secobarbital (i.m.), pentobarbital (p.o.), butabarbital (p.o.) and phenobarbital (p.o.) reinstated responding for saline. The onset of behavioral responding was related to the pharmacokinetic properties of the drugs, with phenobarbital greater than pentobarbital = butabarbital. In contrast, cocaine and d-amphetamine i.m. failed to reinstate the responding in monkeys which had been trained to self-administer thiamylal. These data support the hypothesis that drugs producing responding at a rate significantly greater than that produced by vehicle controls share reinforcing properties with the reference drug.

Animals↗
PubMed1976

Performance enhancement effects of d-amphetamine, methylphenidate, pipradrol and phenindamine in rats.

A multiple behavioral schedule with food reinforcement was designed to measure the drug-induced performance enhancement and non-effective activity in rats. The schedule, 20 min in duration, had CRF components in the 33 trials and extinction components in the inter-trial periods. During each trial, food reinforcement was present in the limited period (8 sec each) which was preceded by a discriminative stimulus (1 sec, either a light or a footshock). The rats generated a high rate of lever pressing during the limited period and a low rate of lever pressing during the inter-trial period. The drugs studied were d-amphetamine, methylphenidate, pipradrol and phenindamine. At low dosages, these drugs increased further the high rate of lever pressing. This was considered to be the performance enhancement effect. At higher doses, the drugs increased the low rate of lever pressing, decreased the high rate of lever pressing, and decreased responding of the rats to the discriminative stimulus. This latter pattern was considered to be the non-effective activity caused by the drugs. As expected, d-amphetamine was the most potent. Minor differences in drug effects were seen between the group of rats having light and that group having footshock as discriminative stimulus.

Animals↗
PubMed1976

Evaluation of narcotic and narcotic antagonist interactions in primates.

Multiple and single drug interactions were studied in morphine-dependent monkeys whose dependency was maintained by self-infusion. Naloxone, naltrexone, and cyclazocine precipitated abstinence syndrome which the animals generally controlled with increased morphine intake. Methadone and L-alpha-acetylmethadol (LAAM) initially reduced, then increased, the morphine intake. Multiple interactions were studied using ethanol, seconal, diazepam, amphetamine, and diphenylhydantoin.

Animals↗
PubMed1976

Biogenic amines and the photomyoclonic syndrome in the baboon, Papio papio.

The role of biogenic amines in the proclivity of the baboon, Papio papio, to exhibit an epileptoid response to flashing light was studied. Intraventricular injections of epinephrine and norepinephrine reduced or blocked the photomyoclonic syndrome without modifying ongoing behavior. Epinephrine was effective at doses of 100 mg and more, and norepinephrine was effective at doses of 250 mg and more. Neither intraventricular injections of as much as 1.5 mg of dopamine and 1.0 mg of serotonin nor chronic systemic administration of L-dopa and L-tryptophan affected the syndrome, but reserpine, administered chronically at doses of 0.5 and 1.0 mg/kg/day, induced photosensitivity in previously nonphotosensitive animals. Seizure testing of usually photosensitive animals 12 hours after reserpine, 0.5 mg/kg, showed that the drug prevented totally or reduced the intensity of seizures in these animals. Studies of the spontaneous electroencephalogram and of visually evoked potentials of the reserpine-treated animals revealed changes in power spectra and in the averaged evoked response from the occipital area which paralleled the induction of photosensitivity. The probability that epinephrine and norepinephrine brain concentrations are essential for inhibitory modulation and control of seizures in this species is discussed.

Animals↗
PubMed1976

Assessment of CNS drug activity in rhesus monkeys by analysis of the EEG.

The data generated from the application of spectral analytical techniques to the analysis of electroencephalograms (EEG) provide a reliable base for the quantification of such data. Drugs with a wide range of central nervous system (CNS) activities were characterized by their effects on neocortical EEGs of Macaca mulatta monkeys according to the specificity of autospectral changes at different anatomical sites. Changes in total spectral power, in the shape of the spectral envelope, and in the relative stability of the drug-induced EEG were assessed at various doses. Electroencephalograms were recorded from epidural electrodes under resting conditions and under the influence of CNS drugs. Autospectra representing sequential 4-second samples of EEG were generated successively over a nominal frequency band of 0-64 Hz. Averages of sequential autospectra were computed over specified time periods. Spectral power over the entire bandwidth and selected frequency regions was calculated and compared. This facilitated the grouping of drugs with similar activities, as well as the distinguishing of changes not readily detectable by visual inspection of the conventional EEG in the time domain.

Amobarbital↗
PubMed1975

In vivo protein synthesis in morphine tolerant monkey brain.

Most investigations dealing with brain protein synthesis in opiate tolerant animals have been restricted to rodent species (rat, mouse and rabbit). We now report data obtained from the monkey (Macaca mulatta). In vivo incorporation of [U-14C]lysine into acid-precipitable protein of various areas of normal and opiate tolerant primate brain was studied. Exposure of the animals to a 1 hour pulse of the radioactive amino acid resulted in no significant difference in the incorporation rate into protein of 16 discrete brain areas.

Animals↗