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Drugs that affect peripheral adrenergic neurotransmission were injected via implanted cannulas into the perifornical region near the posterior part of the anterior hypothalamus of satiated rats, in order to test the hypothesis that in this part of the hypothalamus particularly norepinephrine (NE) functions as a modulator of the neural system involved in regulating eating behavior. The data show that a standard injection of 20 mμ moles of NE, a compound which specifically activates alpha receptors, consistently elicited eating in satiated rats, while doses from 10–150 mμ moles of isoproterenol, a specific activator of beta receptors, did not. Forty and 120 mμ moles propranolol, an adrenergic beta-receptor blocking agent, had no effect on the eating produced by NE but 40 mμ moles of phentolamine, an adrenergic alpha-blocking agent, completely prevented this eating response to NE. Twenty mμ moles of epinephrine elicited significantly more eating than did 20 mμ moles of NE. Neither serotonin (20 mμ moles) nor dopamine (20 or 100 mμ moles) elicited prompt eating, although there was a suggestion of a delayed effect to dopamine, which is a precursor of NE. Desmethylimipramine (400 mμ moles) and lidocaine, inhibitors of the reuptake of NE into the presynaptic terminal, potentiated at least 8-fold the action of 5 mμ moles of NE. The monoamine oxidase inhibitor nialamide (200 mμ moles) elicited eating behavior when followed by 100 mμ moles of tetrabenazine, a substance which blocks the incorporation of free NE in the granules. As would be expected, the reverse sequence of these drugs did not elicit eating. These results are interpreted as strong support for the hypothesis that a specifically adrenergic hypothalamic system is involved in the eating behavior of the rat.

A distinctive biphasic hyperglycaemia, similar to that observed after electrical stimulation of the lateral hypothalamus in the region of the feeding system, was seen in hungry rats after a 3 min presentation of an unreinforced visual discriminative stimulus (DS) during which the rats pressed a lever for food reinforcement at variable intervals, as they had been trained under food deprivation. A monophasic hyperglycaemia was seen after presentation of the same visual stimulus to undeprived animals trained to escape or to avoid foot shock by pressing the lever during DS presentation. No appreciable blood glucose variations were seen with a water-DS under thirst or with the visual stimulus before training. Food deprivation was necessary to the oscillatory glucose response to the food-DS. The response was eliminated by injections of novocaine bilaterally through chronic intrahypothalamic cannulae which were also capable of eliciting eating when used to guide noradrenaline injections. These results provide further evidence that the feeding system mediates direct metabolic effects as well as behavioral control.

Nerve impulse activity was recorded from the descending tract of the trigeminal nerve before and after application of certain noxious stimuli to the exposed dentin of teeth. Heat, electric shocks, concentrated potassium chloride solutions, and negative pressure increased the firing frequency of a majority of the neurons monitored.

One group of freely-moving rats was trained to increase, and another to decrease, heart rate in order to avoid and/or escape electric shock. This training produced a statistically reliable difference between the groups. This difference persisted when the rats subsequently were tested and then given additional training while paralyzed with curare and maintained on artificial respiration. The same difference also persisted during subsequent nonreinforced tests without curare and was further increased by additional reinforced training in the normal, free-moving state. During the initial session of noncurarized training, the group rewarded for increases in heart rate showed more activity than the one rewarded for decreases, but there were no reliable differences in respiration rate. At the end of the second session of noncurarized training, the difference between the groups did not approach statistical reliability in activity (t=0.7), respiration rate (t=0.2), or the variability of that rate (t=0.6), but was highly reliable in heart-rate (t=7.2, df=12, p

(1948). Minor Studies of Aggression: II. the Influence of Frustrations Imposed by the In-Group on Attitudes Expressed Toward Out-Groups. The Journal of Psychology: Vol. 25, No. 2, pp. 437-442.

Reviews the book Theories of Learning, by Ernest R. Hilgard (see record 2005-05010-000). This is a “middle” book. It has the advantages and disadvantages of being in between. It is half way between the undergraduate and graduate level. Thus it can be used profitably at either level, but must be supplemented at each. Although the writing is clear and simple, only the most advanced undergraduates will have enough background to achieve good understanding without carefully planned supplementary readings and lectures. At the same time, most teachers at the graduate level will want to go beyond this book with assignments from original materials and more detailed discussions. At both levels, the suggested readings at the end of each chapter will be helpful. This book is also somewhere between a completely impartial survey and a polemic treatise that sets out to make a case against stimulus-response theories and for field-cognitive ones. Finally, it is a middle-sized book. The topics covered and the pages devoted to each are as follows: Introduction, 18; Thorndike, 32; Guthrie, 24; Hull, 40; Skinner, 30; Current Functionalism, 31; Gestalt, 32; Lewin, 25; Wheeler, 27; Tolman, 33; Theories Influenced by Field Conceptions, 31; A Point of View, 37; and References, 34. (PsycINFO Database Record (c) 2006 APA, all rights reserved)

Two experiments in rats supported previous suggestions that drinking induced by intrahypothalamic injections of carbachol directly activates a thirst motivational system. In Experiment 1 the palatability and osmotic properties of the drinking fluids were varied by presenting different concentrations of NaCl solution in one-and two-bottle drinking tests. Drinking induced by carbachol was found to be closely related to the concentration of the drinking fluid, being augmented when a palatable dilute saline solution was available but decreasing when the unpalatable concentrated solutions were presented instead. Fluid intakes were similar in this regard to the well-known preference-aversion curves for NaCl solutions produced by rats made thirsty by water deprivation. These findings indicate that the carbachol injections, like normal thirst, produce a motivated behavior and not mere reflexive drinking. In Experiment 2 body fluid and tissue analyses revealed that there were no changes in plasma volume or osmolarity associated with the carbachol injections. These findings indicate that the drinking which follows the cholinergic stimulations are due to the direct activation of central neural structures controlling water balance and are not secondary to systemic alterations of body fluids.

Distinctive patterns of behavior can be elicited by directly stimulating the brain with substances that are normally found in it, or with synthetic compounds resembling these substances. Recent research shows that the response elicited depends on both the site stimulated and the type of chemical used. Compounds of different classes, applied via the same cannula to exactly the same site in the brain, can elicit different kinds of behavior, or opposite effects on the same kind of behavior. This differential sensitivity is useful in tracing the circuits in the brain that control different types of behavior, especially since some of these circuits are intimately interlaced in certain places. A better understanding of the chemical coding of behavioral systems in the brain may also help ultimately to provide a more rational foundation for the discovery of new drugs to treat certain forms of mental disorder.

Nine free-moving rats were trained to increase, and eight to decrease, systolic blood pressure in order to avoid and/or escape electric shock. The initial difference in blood pressure between the two groups was small and did not approach significance. The training produced changes in the rewarded directions, with the difference between the changes being reliable and producing an overall difference of 9.7 mm Hg. No corresponding changes were found for heart rate or gross skeletal acfivity. The blood pressure responses failed to transfer to the curarized state. However, subsequent training in the curarized state produced a difference between the increase and decrease groups of 21.2 mm Hg. There was some indication that the blood pressure responses in the curarized and noncurarized training sessions were positively correlated.

Passage of current for brief periods through electrodes in the lateral hypothalamus virtually always resulted in a distinctive biphasic hyperglycaemia in the case of electrodes capable of eliciting feeding at similar current intensities. The biphasic hyperglycaemic response was sometimes elicited by electrodes aimed at the feeding area but not capable of eliciting feeding. The response remained under pentobarbital anaesthesia. Electrodes in other regions of the hypothalamus gave monophasic hyperglycaemia or hypoglycaemia or no blood glucose change. The hyperglycaemic phases of the biphasic response were diminished by an adrenergic alpha-receptor blocking agent and by bilateral adrenal demedullation. The intermediate lowering of blood glucose concentration could be eliminated by injection of atropine or by sub-diaphragmatic bilateral vagotomy. It is therefore possible that the hypothalamic feeding system is directly connected to autonomic systems influencing endocrine regulation of glucose metabolism.

Intraperitoneal injections of Escherichia coli endotoxin in albino rats produces a decrease in food and water intake and a drop in body temperature. The drop in temperature and in water intake is probably proportional to the size of the dose. Using a behavioral test in which animals are trained to press a bar at a steady rate for intermittent food or water reward, it is possible to demonstrate the sudden onset of the toxin effect at 30 to 45 minutes after injection. In any group of rats, all of whom were presumably exposed to E. coli, three types of response to toxin can be found: (a) Sharp reduction in water intake 30 minutes after injection. (b) Little or no change in intake or rate of working for water reward. (c) Immediate depression of work rate. These three types of reaction appear related to previous experience with the toxin. The "normal" or "inexperienced" reaction a was seen in animals who had not been given toxin before. The "protected" reaction b, with little or no effect of toxin injection on response rate was frequently found 4 to 5 days after a previous injection. The "susceptible" reaction c was found in three animals after 14 or more days had passed since a previous injection. Injections of toxin into the lateral hypothalamic region of four animals through implanted cannulae had no effect on the rate of bar pressing for water. Control injections of lidocaine blocked response rate completely for brief periods in three animals.

* Recommended by Walter Miles, accepted for publication by Carl Murchison of the Editorial Board, and received in the Editorial Office, November 14, 1933. 1 The larger part of this work was done as an M.A. Thesis at Stanford University during the winter and spring quarters of 1932. Acknowledgments are hereby made to Dr. Maud A. Merrill, Associate Professor of Psychology, Stanford University, for her guidance and assistance; to Dr. Harold E. Jones, Professor of Psychology and Director of the Institute of Child Welfare at the University of California, for the invitation to use the facilities of the Institute in carrying out a part of this study; to Mrs. Oscar A. Anderson for the use of the facilities of her Palo Alto Nursery School; to Dr. Helen Thompson, Research Associate in the Clinic of Child Development, Yale University, for assistance in securing subjects; and to Dr. Walter R. Miles, Professor of Psychology, Institute of Human Relations, Yale University, for criticizing the manuscript.

Although chlorpromazine is believed to block adrenergic transmission, injection of this drug into the hypothalamus of satiated rats does not block norepinephrine-elicited eating, but instead mimics norepinephrine by eliciting eating. The amount of eating elicited by norepinephrine and by chlorpromazine is reliably correlated. These results suggest that endogenous norepinephrine mediates eating elicited by centrally injected chlorpromazine.

Lateral hypothalamic lesions in rats caused a pronounced depression of drinking in response to injections of carbachol into the preoptic area or the posterior hypothalamus. After the lesions were induced, daily free water consumption recovered 70 to 80 percent of that of control animals, but there was little, if any, recovery of drinking induced by carbachol.

Well-organized eating and grooming behaviors were elicited in cats by stimulation of a zone in the cerebellum that extended from the fastigial nucleus to the superior cerebellar peduncle. Behaviors appeared to result from the facilitation of specific sensorimotor mechanisms, rather than the induction of generalized “drive” states. The results emphasize the need for a broad view of cerebellar function.