Paradoxical effects of amphetamine on preweanling and postweanling rats

In adult rats amphetamine acts as a strong behavioral stimulant leading to a marked increase in random, nondirected locomotor activity. In contrast we report that amphetamine administered to preweanling rats in the presence of an anesthetized adult rat produces no visible increase in motor activity. Instead, it appears to enhance the normal tendency of neonatal rats to approach and maintain contact with conspecifics. In postweanling rats amphetamine disrupts the tendency to aggregate and produces an increase in behavioral activity comparable to that seen in adult rats. These findings may constitute the basis for an animal model of minimal brain dysfunction hyperkinesis.     

Ascorbic acid and the behavioral response to haloperidol: implications for the action of antipsychotic drugs

Haloperidol, a widely used antipsychotic drug, was tested for its ability to block the behavioral response to amphetamine and to elicit catalepsy in rats treated with saline or ascorbic acid (1000 milligrams per kilogram of body weight). By itself, ascorbic acid failed to exert significant behavioral effects, but it enhanced the antiamphetamine and cataleptogenic effects of haloperidol (0.1 or 0.5 milligrams per kilogram). These results, combined with a growing body of biochemical evidence, suggest that ascorbic acid plays an important role in modulating the behavioral effects of haloperidol and related antipsychotic drugs.     

用水迷宫建立大鼠空间辨别性学习记忆模型

目的探索脑形态与脑功能结合的动物模型建立方法．方法用水迷宫训练大鼠建立空间辨别性学习记忆模型．结果用水迷宫每天训练10次，连续7d即可这到预定的模型标准；在建立模型的过程中发现在训练的第5天有学习的平台期出现．结论水迷宫训练实验能有效的使大鼠建立空间辨别性学习记忆能力．     

Effects of long-term reserpine treatment on brain tyrosine hydroxylase and behavioral activity

Treatment of rats with reserpine (for 8 or 9 days) produced a temporally related increase in behavioral activity and in tyrosine hydroxylase activity in the midbrain. Weight loss resulting from such treatment was not sufficient, by itself, to account for either the behavioral or enzymatic changes. The results support the role of catecholamines in behavioral arousal.     

Prolactin stimulation of maternal behavior in female rats

Inexperienced, hypophysectomized female rats treated with steroids were used in experiments to investigate the roles of the pituitary gland and prolactin in the expression of maternal behavior. Administration of ovine prolactin or treatment with ectopic pituitary grafts, which release prolactin into the circulation, stimulated maternal care in these females toward rat young. Steroid treatment alone, while stimulating maternal behavior in rats with intact pituitary glands, did not facilitate maternal responsiveness in hypophysectomized females. These findings indicate a stimulatory behavioral role for pituitary prolactin in the establishment of maternal care and suggest that exposure to prolactin during pregnancy helps to stimulate the immediate onset of maternal behavior at parturition.     

清肝宁肺汤对咳嗽变异性哮喘大鼠模型疗效的实验研究

目的探讨清肝宁肺汤对咳嗽变异性哮喘(CVA)大鼠模型的疗效。方法通过注射卵蛋白(OA)致敏、雾化吸入OA和辣椒素刺激咳嗽的方法,复制CVA大鼠模型。随机分为正常组、模型组、地塞米松片组、清肝宁肺汤组、清肝宁肺汤合地塞米松片组(以下简称为清肺汤加地米组),以2 min内咳嗽次数,肺、气管及心脏体质量指数,肺组织病理变化,体质量和死亡率为指标。结果与正常组比较,模型组大鼠咳嗽次数显著增加(P<0.01),肺及气管、心脏体质量指数升高,差异有统计学意义(P<0.01),肺组织病理切片可见炎性改变。给药后各组上述指标均有所改善,差异有统计学意义(P<0.05或P<0.01),清肺汤加地米组和地塞米松片组起效快,但地塞米松片组体质量下降明显,死亡率高。结论清肝宁肺汤能够有效治疗CVA,并能降低地塞米松片的毒副作用。     

Methamphetamine-induced insulin release

Administration of methamphetamine or amphetamine to rats and mice produces a rapid increase in the level of immunoassayable plasma insulin not attributable to hyperglycemia. While in the mouse this release of insulin is followed consistently by a profound hypoglycemia, in the rat this response is variable. Studies in vitro demonstrate that insulin is released by a direct effect of methamphetamine on the pancreas.     

Ontogeny of adrenergic arousal and cholinergic inhibitory mechanisms in the rat

With spontaneous activity as a measure of arousal, dose response curves were established for scopolamine and amphetamine administered to 10-, 15-, 20-, 25-, and 100-day-old rats. Amphetamine always increased activity, but scopolamine had no efect on younger rats, which suggests that adrenergic excitatory areas in the brainstem mature more rapidly than cholinergic inhibitory areas in the forebrain.     

Abolition and reversal of strain differences in behavioral responses to drugs of abuse after a brief experience

Inbred strains of mice are largely used to identify the genetic basis of normal and pathological behaviors. This report demonstrates that a moderate period of food shortage, an ecologically common experience, can reverse or abolish strain differences in behavioral responses to the abused psychostimulant amphetamine. The period of food shortage occurred when the animals were mature and was terminated before the administration of amphetamine. Strain differences in behavior appear highly dependent on environmental experiences. Consequently, to identify biological determinants of behavior, an integrated approach considering the interaction between environmental and genetic factors needs to be used.     

Inactivation of the interoceptive insula disrupts drug craving and malaise induced by lithium

Addiction profoundly alters motivational circuits so that drugs become powerful reinforcers of behavior. The interoceptive system continuously updates homeostatic and emotional information that are important elements in motivational decisions. We tested the idea that interoceptive information is essential in drug craving and in the behavioral signs of malaise. We inactivated the primary interoceptive cortex in amphetamine-experienced rats, which prevented the urge to seek amphetamine in a place preference task. Interoceptive insula inactivation also blunted the signs of malaise induced by acute lithium administration. Drug-seeking and malaise both induced Fos expression, a marker of neuronal activation, in the insula. We conclude that the insular cortex is a key structure in the perception of bodily needs that provides direction to motivated behaviors.     

那瓦斯坦与肝素、罂粟碱治疗动脉硬化闭塞症疗效比较

目的观察比较那瓦斯坦与肝素、罂粟碱治疗动脉硬化闭塞症的疗效及安全性.方法将100例患者随机分为A,B两组,A组（50例）患者给予那瓦斯坦注射液20 mg/次,1次/d,连续给药10 d;B组（50例）患者给予罂粟碱注射液30 mg/次,以250 mL生理盐水注射液稀释,2次/d;肝素5 000 U/次皮下注射,2次/d,给药10 d.观察患者用药后间歇性跛行、麻木等症状改善状况以及药物不良反应.结果 A组患者治疗有效率为84%,B组患者治疗有效率为68%.两组患者都未出现心脑血管及胃肠道出血等严重不良反应.结论两种治疗方法比较,A组更加有效,且起效迅速,A,B两种治疗方法均较安全.     

Role for the membrane receptor guanylyl cyclase-C in attention deficiency and hyperactive behavior

Midbrain dopamine neurons regulate many important behavioral processes, and their dysfunctions are associated with several human neuropsychiatric disorders such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. Here, we report that these neurons in mice selectively express guanylyl cyclase-C (GC-C), a membrane receptor previously thought to be expressed mainly in the intestine. GC-C activation potentiates the excitatory responses mediated by glutamate and acetylcholine receptors via the activity of guanosine 3',5'-monophosphate-dependent protein kinase (PKG). Mice in which GC-C has been knocked out exhibit hyperactivity and attention deficits. Moreover, their behavioral phenotypes are reversed by ADHD therapeutics and a PKG activator. These results indicate important behavioral and physiological functions for the GC-C/PKG signaling pathway within the brain and suggest new therapeutic targets for neuropsychiatric disorders related to the malfunctions of midbrain dopamine neurons.     

加卡利亚仓鼠行为特性研究

随机选择5只50~60日龄,健康的加卡利亚仓鼠,2雌3雄,体重为(35.4±7.3)g,对其采食、饮水、排泄、睡眠以及繁殖等行为进行8 d的连续观测,并对仔鼠生长发育情况进行了观测。结果表明,加卡利亚仓鼠的日采食量为(9.28±1.32)g,以傍晚的采食量最多。采食持续时间平均为(17.4±4.9)min。日饮水次数平均为(13.13±2.1)次,日饮水量为(3.89±0.32 ml)。日排粪次数为(19.25±4.03)次,排粪量为(8.19±1.71)g,每次的排尿量0.8~1.5 ml。日睡眠时间为10~12 h,日间几乎处于睡眠状态。仔鼠从第2、3周龄开始体重增加较快,2月龄以后,体重变化不大。     

Long-term amphetamine treatment decreases brain serotonin metabolism: implications for theories of schizophrenia

Long-term amphetamine administration to cats (a mean of 8.75 milligrams per kilogram twice daily for 10 days) produced large decreases (40 to 67 percent in serotonin and its major metabolite, 5-hydroxyindoleacetic acid, in all brain regions examined. This treatment also produced several behaviors that are dependent on depressed central serotonergic neurotransmission, and which normally are elicited exclusively by hallucinogenic drugs. Short-term amphetamine administration (15 mg/kg) did not produce these behaviors and resulted in small decreases in brain serotonin and no change in 5-hydroxyindoleacetic acid. These data are discussed in the context of monoamine theories of schizophrenia.     

Early experiences accelerate maturation of the 24-hour adrenocortical rhythm

Rats reared under 12-hour alternating periods of light and dark were killed at times corresponding to the times at which the maximum or minimum plasma corticosterone concentrations occur in mature animals. The characteristic 24-hour adrenocortical rhythm was first observed in rats 21 to 25 days old. In rats handled or stimulated with electric shock, the rhythm developed as early as 16 days.     

RUNNING AS BOTH A POSITIVE AND NEGATIVE REINFORCER

Rats were required to press a bar to activate a motor-driven wheel that forced them to run and subsequently to drink to turn off the wheel. Barpressing and lickilng increased, showing the onset and offset of running to be positively and negatively reinforcing, respectively. The experimental control of the offset of running, in contrast to the traditional control for onset only, served to demonstrate that since organisms stop such behaviors as they start, self-initiated behaviors will act as negative as well as positive reinforcers.     

Hormonal effects on ontogeny of swimming ability in the rat: assessment of central nervous system development

The maturation of swimming behavior and the evoked cortical response to sciatic stimulation were studied in newborn rats receiving thyroxine or cortisol. Compared to that of controls the maturation of swimming is accelerated or delayed 2 to 3 days by thyroxine or cortisol treatment, respectively, and this corresponds to ontogenetic shifts in the characteristics of the evoked potential. Front leg movement during swimming normally diminishes at about 16 days of age and is inhibited by day 22. Thyroxine also advances and cortisol delays the age at which this inhibitory mechanism becomes evident, and compresses (thyroxine) or expands (cortisol) the time interval over which it becomes functional. During early postnatal life certain circuilating hormones can affect the rate and chronology of central nervous system maturation. Swimming behavior may be a simple model to use in studies concerned with factors affecting the functional and behavioral development of the central nervouts system.     

Strain differences in rat brain epinephrine synthesis: regulation of alpha-adrenergic receptor number by epinephrine

Inbred tht strains Fischer 344 (F344) and Buffalo (BUF) differ in serveral physiological and behavioral measures. It was found that the activity of adrenomedullary and regional brain phenylethanolamine N-methyltransferase is at least four times higher in F344 rats than in BUF rats; these strain-dependent differences corresponded directly with the epinephrine content of the medulla-pons and hypothalamus. Conversely, alpha-adrenergic receptor density in brain regions containing phenylethanolamine N-methyltransferase is two to three times lower in F344 rats than in BUF rats; alpha-receptors in frontal cortex (a brain region lacking phenylethanolamine N-methyltransferase activity and epinephrine) are similar in both strains. These findings suggest that strain-dependent differences in alpha-receptors are regulated by inherited differences in presynaptic adrenergic neuronal function in different brain regions.     

Acquisition and retention of long-term habituation in Aplysia: correlation of behavioral and cellular processes

To examine the cellular mechanisms responsible for transition from a short-term to a long-term behavioral modification, a rapid training procedure was developed for producing long-term habituation of the defensive withdrawal of gill and siphon in Aplysia. Four ten-trial training sessions, with 1(1/2)-hour intersession intervals, produced habituation that was retained for more than 1 week. This 5-hour procedure could be applied to a test system in the isolated abdominal ganglion where the cellular changes accompanying the acquisition of long-term habituation can be examined. During acquisition, intracellular recordings were obtained from L7, a major gill and siphon motor neuron, and the pattern of stimulation used in the behavioral experiments was applied to an afferent nerve. Acquisition was associated with a progressive decrease in the complex excitatory synaptic potential produced in L7 by afferent nerve stimulation. When retention was tested 24 hours later, the synaptic decrement was still evident. Thus, a behaviorally meaningful stimulus sequence, consisting of only 40 patterned stimuli, leads to changes in synaptic effectiveness lasting one or more days in a neural pathway involved in short-term habituation of this reflex.     

Endogenous opiates mediate radiogenic behavioral change

Exposure of C57BL/6J mice to ionizing radiation caused stereotypical locomotor hyperactivity similar to that produced by morphine. Naloxone administration prevented this radiation-induced behavioral activation. These results support the hypothesis that endorphins are involved in some aspects of radiogenic behavioral change.