6-Hydroxydopa depletion of brain norepinephrine and the function of aggressive behavior

A significant increase in shock-induced aggression occurs in the rat 4 days after an intraventricular injection of 90 micrograms of 6-hydroxydopa. Both fluorescent histology and biochemical assay demonstrate that brain norepinephrine is reduced by 90 micrograms of 6-hydroxydopa, while brain dopamine remains unaltered. This suggests that one form of aggressive behavior (shock-induced aggression) is modulated through a central noradrenergic system.     

Tritiated norepinephrine: release from brain slices by electrical stimulation

Slices of rat brain and heart that had concentrated H(3)-norepinephrine were superfused and electrically stimulated. Stimulation induced a marked release of H(3)-norepinephrine with a threshold and a maximum repsonse. Release also occurred with increased concentrations of potassium, presumably due to neuronal depolarization. Inhibition of electrically induced release occurred with low calcium and with chlorpromazine and pentobarbital.     

Hormone-induced sexual differentiation of brain and behavior in zebra finches

The male zebra finch sings, whereas the female does not. This behavioral dimorphism is correlated with the presence of morphological sex differences within the neural substrate that mediates this behavior, the song system. When a female chick is exposed to 17beta-estradiol her song system is subsequently masculinized. Either testosterone or 5alpha-dihydrotestosterone may then induce such a female to sing when an adult.     

Evoked release of norepinephrine and serotonin from brain slices: inhibitoon by lithium

Slices of mammalian brain accumulate H(3)-norepinephrine and H(3)-serotonin when incubated in a physiologic medium containing these tritiated monoamines. When these tissues are subjected to mild electrical stimulation of short duration, which is associated with depolarization of nerve membranes, a striking increase in the rate of efflux of the exogenous labeled monoamines occurs. Stimulation-induced release of both labeled monoamines is diminished by the presence of lithium ions in the perfusing medium; related monovalent cations had no such effect. Evoked release from slices of brain from animals treated intraperitoneally with lithium chloride for 3 days was also reduced.     

Facilitation of brain self-stimulation by central administration of norepinephrine

Rats with electrodes implanted in the medial forebrain bundle stimulated their own brains at sharply reduced rates after systemic administration of disulfiram or intraventricular administration of diethyldithiocarbamate. Both drugs inhibit dopamine-beta-hydroxylase, the enzyme responsible for the final step in the biosynthesis of norepinephrine. The suppressed behavior was reinstated by intraventricular injections of 1-norepinephrine, but not by injection of its biologically inactive isomer, d-norepinephrine. Intraventricular administration of dopamine and serotonin did not restore self-stimulation. The rewarding effect of medial forebrain bundle stimulation may depend on the availability of norepinephrine as a transmitter, but not on dopamine or serotonin.     

Depression of norepinephrine and 5-hydroxytryptamine in the brain by benzoquinolizine derivatives

The effects of two benzoquinolizine derivatives on the 5-hydroxytryptamine and norepinephrine content of the brain of mice, and some pharmacological actions, are described. Certain central effects (such as sedation and narcosis potentiation) of benzoquinolizine derivatives and possibly of Rauwolfia alkaloids may be due to changes of norepinephrine metabolism rather than to changes of 5-hydroxytryptamine metabolism in the brain.     

Amphetamine effects in man: paradoxical drowsiness and lowered electrical brain acitivity (CNV)

Thirteen of 20 normal adults given 10 milligrams of dextroamphetamine exhibited paradoxical drowsiness accompanied by lowered electrical brain activity (contingent negative variation, or CNV) in the first hour post-drug. During this period, seven subjects showed behavioral alertness and increased CNV amplitude. Both groups of subjects showed heightened alertness 2 and 3 hours post-drug. Amphetamine is not a simple stimulant of the central nervous system but can also act as a depressant.     

L-dopa: effect on concentrations of dopamine, norepinephrine, and serotonin in brains of mice

Large doses of L-dopa given to mice produced marked increases in brain dopamine, no change in norepinephrine, and a remarkable decrease in brain serotonin. This reduction apparently results from a release or displacement, or both, of serotonin from its storage sites.     

Object-carrying by rats: an approach to the behavior produced by brain stimulation

Rats were provided with opportunity to turn reinforcing hypothalamic stimulation on and off by traversing back and forth across a chamber. When provided with edible and inedible objects, all animals that self-stimulated carried them from the stimulation to the nonstimulation side. Neither food deprivation nor a history of stimulus-bound eating produced a preference for the edible objects. Equivalent stimulation provided without regard to the animals' location in the chamber did not elicit object-carrying. Results are interpreted in terms of the natural conditions which normally elicit this species-specific unit of behavior. Implications for understanding other behavior patterns elicited by hypothalamic stimulation are suggested.     

Polychlorinated biphenyls: metabolic behavior of pure isomers in pigeons, rats, and brook trout

The metabolic behavior of pure mono-, di-, tetra-, and hexachlorobiphenyl isomers in pigeons, rats, and brook trout was investigated. Excreta from these animals were extracted and examined by chromatographic and mass spectrometric techniques. The results showed conversion of the 4-chloro-, 4,4'-dichloro-, and 2,2',5,5'-tetrachlorobiphenyl isomers into monohydroxylated derivatives by the rat and pigeon whereas no hydroxymetabolites were detected in the excreta of the brook trout. No hydroxylated products of 2,2',4,4',5,5'-hexachlorobiphenyl were detected in the excreta of pigeons, rats, or brook trout.     

Potentiation of epinephrine and norepinephrine by iproniazid

The effects of pretreatment with iproniazid on the toxicity and cataract-producing ability of epinephrine and norepinephrine were studied. The epinephrine and norepinephrine were administered in such a way that a slow, prolonged rate of absorption was achieved. Under these conditions, the lethality and cataract-producing ability of these amines were shown to be significantly enhanced by the action of iproniazid.     

Uptake of tritium-labeled norepinephrine in brain and other tissues of cat in vitro

Slices of cat cerebral cortex, heart, and spleen that have been incubated in media containing approximately 5 to 25 mmicrog of dl-norepinephrine-7H(8) per milliliter contain levels of isotopic amine greater than those in the medium. The effects of norepinephrine concentration, reserpine, and ouabain on the uptake suggest that the amine enters cells both by diffusion and by a concentrating miechanism that is saturated at low levels of norepinephrine. The drugs inhibit the latter.     

Simultaneous study of behavior and brain waves

A technique for the simultaneous audiovisual recording of behavior and brain waves is described. The absence of muscle movement artifact, despite unlimited activity of the patient, suggests that telemetering may be adaptable for routine electroencephalography.     

Quantitative analysis of D2 dopamine receptor binding in the living human brain by PET

D2 dopamine receptors in the putamen of living human subjects were characterized by using the selective, high-affinity D2 dopamine receptor antagonist carbon-11-labeled raclopride and positron emission tomography. Experiments in four healthy men demonstrated saturability of [11C]raclopride binding to an apparently homogeneous population of sites with Hill coefficients close to unity. In the normal putamen, maximum binding ranged from 12 to 17 picomoles per cubic centimeter and dissociation constants from 3.4 to 4.7 nanomolar. Maximum binding for human putamen at autopsy was 15 picomoles per cubic centimeter. Studies of [11C]raclopride binding indicate that clinically effective doses of chemically distinct neuroleptic drugs result in 85 to 90 percent occupancy of D2 dopamine receptors in the putamen of schizophrenic patients.     

农民合作社规制与社员绿色生产行为：激励抑或约束

为探究农民合作社规制对社员绿色生产行为的影响,利用四川省695份社员微观调查数据和Oprobit等模型,对合作社激励性和约束性规制的影响及交互作用进行了实证检验,结果表明：1）农民合作社激励性和约束性规制均够促使社员参与绿色生产。2）异质性层面,合作社规制更能促使生产规模大、文化程度高等类别社员参与绿色生产,小规模、低收入群体更适用于激励性规制。3）分散经营型合作社对社员生产行为的规制作用明显弱化,而经济激励可以有效缓解规制弱化问题。村委领办型合作社的约束性规制作用明显大于个人领办型,完全横向合作型合作社约束性规制作用更强。4）合作社约束性规制和激励性规制之间起到了负向调节的作用,即约束性规制的增强削弱了激励性规制的作用强度,而激励性规制的强化也会一定程度上减小约束性作用。基于此,提出加强对经济欠发达区、小规模、低收入社员的经济激励力度;强化硬性制度要求对经济发达区、资源禀赋较高社员群体的约束作用;根据合作社经营模式、领办主体和产品销路等组织特质选取约束性或激励性规制。     

Phenobarbital: effects of long-term administration on behavior and brain of artificially reared rats

Two doses of phenobarbital were given daily for 2 weeks to infant rats fed by intragastric cannulas. The larger dose (60 milligrams per kilogram of body weight) resulted in decreased spontaneous activity and increased responses to novel stimuli. The smaller dose (15 milligrams per kilogram) resulted in increased spontaneous activity and also an increase of responses to novel stimuli. The larger dose produced a 12 percent reduction in brain growth, while the smaller dose was associated with a 3 percent reduction in brain growth.