Brainstem mediates diazepam enhancement of palatability and feeding: microinjections into fourth ventricle versus lateral ventricle

The hypothesis that benzodiazepine-induced hyperphagia is due to a specific enhancement of the palatability of foods has been supported by previous ‘taste reactivity’ studies of affective (hedonic and aversive) reactions to taste palatability. Diazepam and chlordiazepoxide enhance hedonic reactions of rats (rhythmic tongue protrusions, etc.) to sweet tastes in a receptor-specific fashion. A role for brainstem circuits has been indicated by a previous demonstration of the persistence of the taste reactivity enhancement by diazepam after midbrain decerebration. The present study examined whether benzodiazepine brainstem receptors are the chief substrates for palatability enhancement even in intact brains. We compared the effectiveness of benzodiazepine microinjections to elicit feeding and enhance hedonic reactions when delivered into either the lateral ventricle (forebrain) or the fourth ventricle (brainstem) of rats. The results show diazepam is reliably more effective at eliciting feeding and enhancing positive hedonic reactions to oral sucrose when microinjections are made in the fourth ventricle than in the lateral ventricle. We conclude that brainstem neural systems containing benzodiazepine-GABA receptors are likely to be the chief substrates for benzodiazepine-induced palatability enhancement.     

脑动静脉畸形的供应动脉及导出静脉与出血危险性的关系

本文通过分析５０例脑动静脉畸形（ＡＶＭ）的全脑数字减影血管造影（ＤＳＡ）资料及手术探查结果，探讨ＡＶＭ的深、浅及供血、引流血管数量与出血发生率的关系。经统计比较发现：深部较浅部ＡＶＭ出血率高；供应动脉条数多于导出静脉条数者及仅有单条导出静脉出血率最高，并与其他组有显著性差异（Ｐ＜０．０５、Ｐ＜０．０１）。因此，我们认为：在临床工作中对这些ＡＶＭ患者应给予足够的重视。     

The kappa-opioid U-50,488H suppresses the initiation of nocturnal spontaneous drinking in normally hydrated rats

The effect of a systemic (IP) treatment with 1.0, 3.0 and 9.0 mg/kg U-50,488H (U50), a highly selective kappa-agonist, on spontaneous, nocturnal ingestive behavior of the rat was studied using a microcomputer controlled data acquisition system. The latency to initiate drinking was increased and drinking behavior was suppressed in the first hour after injection in a dose-dependent manner. The consummatory indices of drinking were not affected. After this period of adipsia, a phase of polydipsia, that was probably due to the diuretic effect of U50, was evident. The prophagic effect of U50 was evident only at the dose of 3 mg/kg and was accompanied by an increased duration of feeding episodes but not by a reduced latency to feed. These results suggest that kappa-receptors play a pivotal role in modulating spontaneous drinking in the normally hydrated rat and that this control is mainly exerted on the motivational aspect of drinking.     

喂饲泵应用的临床观察及护理

目的 探讨用喂饲泵行肠内营养摄入的临床应用价值。方法 实验组30例采用喂饲泵控制肠内营养液的滴入速度，对照组采用传统方法，用20ml或50ml注射器灌注营养液，观察两组并发症的发生情况，所得量化指标进行卡方检验。结果实验组其返流、呕吐、腹胀、吸入性肺炎的发生率明显低于对照组。结论应用喂饲泵行肠内营养的摄入，可有效预防并发症的发生。     

Effect of Short-Term Ethanol Feeding on Rat Testes as Assessed by 31P NMR Spectroscopy, 1H NMR Imaging, and Biochemical Methods

31P Nuclear magnetic resonance (NMR) spectroscopy and 1H NMR imaging were used to examine the effect of short-term ethanol feeding on the rat testis. Weanling rats were pair-fed for 10 weeks either on ethanol containing liquid diet (36% ethanol of total calories) or a diet in which dextrimaltose was isocalorically substituted for the ethanol of the alcohol-containing diet. In vivo 31P NMR of the testes was used to determine the intratesticular pH and the relative concentrations of various phosphorus-containing metabolites. The integrity of the blood-testes barrier was evaluated using 1H NMR imaging following a gadolinium diethylene tetramine pentaacetic acid derivative (Gd-DTPA) administration as a vascular contrast agent. After the completion of NMR studies, the testis and the liver were freeze-clamped to allow for the assay of their adenosine-5'-triphosphate (ATP) contents. Serum was assayed for its content of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alcohol and testosterone. Ethanol feeding resulted in the following: (a) a reduction in the body weight (p less than 0.05), (b) a reduction in the testicular phosphodiesters (PDE) PDE/ATP ratio (p less than 0.05), (c) an increased change in the testis image intensity difference between pre- and post-iv Gd-DTPA images, (c) a reduction in the testicular and hepatic content of ATP, and (d) increased serum levels of AST and ALT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of acetylcholine on neuronal activity of monkey amygdala during bar press feeding behavior

Single neuron activity in the monkey amygdala was investigated during cue signalled conditioned bar press feeding behavior and the effects of electrophoretically applied acetylcholine (ACh) and atropine were analyzed. ACh increased the firing rate of one third of the neurons tested; these excitatory responses were inhibited by the muscarinic receptor antagonist atropine. No characteristic location of ACh-sensitive neurons was found, cells were diffusely distributed throughout the amygdala. Activity of ACh-sensitive neurons did not correlate with any particular event during the bar press feeding task. However, continuous application of ACh at low current intensity during the task significantly enhanced the task-related excitatory firing patterns, or markedly attenuated the inhibitory responses. Continuous application of atropine elicited or enhanced inhibitory response patterns. These results suggest that the cholinergic system of the monkey amygdala facilitates neuronal excitation but attenuates inhibition related to various phases of feeding behavior, such as to cue recognition, food aquisition and rewarding process.     

Reversal of dexfenfluramine-induced anorexia and c-Fos/c-Jun expression by lesion in the lateral parabrachial nucleus

The external subdivision of the lateral parabrachial nucleus (LPBE) shows strong Fos-like immunoreactivity (FLI) following anorectic doses of the indirect serotonin agonist dexfenfluramine (DFEN). In an effort to determine the contribution of the LPBE to DFEN-induced anorexia, bilateral ibotenate lesions were made in the LPBE, and the effects of the lesion on DFEN-induced anorexia and FLI as well as c-June-like immunoreactivity (JLI) were examined. It was found that LPBE lesion significantly attenuated DFEN anorexia: in a 1-h food intake test following 24-h food deprivation, DFEN (2 mg/kg) suppressed food intake by 60% in intact rats but only 34% in rats with LPBE lesions. In addition to this behavioral change, LPBE lesion completely abolished DFEN-induced FLI and JLI in the lateral subdivision of the central nucleus of the amygdala (CeL) and laterodorsal subdivision of the bed nucleus of stria terminalis (BSTLD), both of which showed strong FLI and JLI in intact rats. DFEN-induced FLI and JLI in other brain regions were not affected by LPBE lesion, including the ventromedial and lateral hypothalamus, caudate-putamen, and the nucleus of the solitary tract (NST). The parallel loss of DFEN-induced anorexia and FLI/JLI following LPBE lesion raises the novel possibility that LPBE-CeL/BSTLD pathway may be involved in DFEN anorexia.     

Changes in the mouthful weights of familiar foods with age of five years,eight years and adults

For effective mastication and swallowing, to take optimum mouthful food regularly is necessary. The purpose of this study is to compare the weights and the variance of a mouthful food between children and adults. We studied mouthful weight and the coefficient variation in 5-year-old children (n = 10), 8-year-old children (n = 10) and adults (n = 10) while they were eating rice, bread, sausage and apple on two different days. The test foods were served in random order 2–4 hours after lunch. Each portion was weighed before and after each bite to measure the mouthful weight, and the weight of the last bite of each portion was eliminated from the data. The mean weight and coefficient variation in each subject were calculated. The results showed the mean weight was largest in the adults, intermediate in the 8-year-old children, and smallest in the 5-year-old children for all test foods (ANOVA). Moreover, the mean coefficient variation among the weights of the groups revealed that mouthful weight within an individual varied most widely in the 5-year-old children and most narrowly in the adults, and that 8-year-old children could show the same coefficient variation of mouthful weight as adults in rice and apple (Steel-Dwass test). Our results suggest that mouthful weight becomes larger and more regularly with age.