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Biomedical subjects

K A Bonnet

Publications and source records attributed to K A Bonnet.

25 records · Page 2Linked to original sources
PubMed1976

Transport of RNA along the optic pathway of the chick: an autoradiographic study.

Autoradiograms of the optic tectum were made 8 days after monocular injection of 3H-uridine in 3 day-old chicks. Electron microscopic analysis of grain density over morphological structures in various layers of the optic tectum contralateral to the injected eye, was carried out. This revealed that the highest concentration of labeled RNA was within the axons of the more superficial layers of the tectum. A lesser density of grains was observed over glial cells, neuronal perikarya and dendrites. In addition, the bulk of the total grains counted were over axons. In lower tectal layers, radioactivity was predominantly over unmyelinated axons and glial elements. High molecular weight RNA appears to be transported within the axons of the optic nerve toward their terminations which are largely in the outer layer of the optic tract.

Animals↗
PubMedDate not supplied

Calmodulin increases in selective brain regions with opioid dependence.

Acute challenge of thalamic membranes with opioid agonists displaces calcium and prevents isoproterenol stimulation of adenylate cyclase. Chronic morphine administration for three days or three weeks results in significant increases in the level of calmodulin in membranes of thalamus, but not in periaqueductal gray, striatum, amygdala or hypothalamus.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMedDate not supplied

A modification of the jump-flinch technique for measuring pain sensitivity in rats.

The jump-flinch procedure provides a sensivite alternative to the hot-plate and tail-flick procedures. Analysis of the components of motor responses to increasing intensity of foot shock presentation has allowed the observational discrimination of five reliably elicited categories of unlearned responses to inescapable foot shock. Morphine sulfate differentially altered response category thresholds in rats. Response category thresholds also differed between Wistar and Fisher strain rats in analgesic effects of morphine sulfate.

Animals↗
PubMedDate not supplied

Survival and development of maternally deprived rats: role of body temperature.

Rat pups, 10-12 days old, survived maternal deprivation if kept warm at 35 degrees, but died within 6 days if allowed to become hypothermic at a room temperature of 23 degrees. Normal body temperatures facilitated feeding, but even without food, warm pups survived starvation longer than cool ones. Increased survival could not be attributed to decreased oxygen consumption, and warm pups lost more body water and solids than cool pups. Striking differences in development that may have affected survival were observed over 72 hr of separation without food. Cool pups showed a virtual arrest of the growth of the tail, fur, tibia, and femur, and failed to increase brain weight, protein, DNA, RNA, and catecholamine contents. Warm pups showed developmental growth more comparable to that of normally mothered pups and significantly exceeded controls in the rate of accumulation of brain norepinephrine and dopamine.

Animals↗