Facilitation or inhibition of memory by morphine: a question of experimental parameters

The effects of morphine on memory are highly controversial. According to some investigators post-trial injections of morphine facilitate memory. Others, however, have reported impairment of memory after morphine injections. To investigate the extent to which this may be due to different experimental parameters, foot-shock intensity and dosage of morphine were systematically varied in a passive-avoidance task. It was found that post-trial administration of medium and relatively high doses of morphine facilitate retention performance following moderate levels of foot-shock. Under other conditions of dose and shock intensity, the drug was not effective or even impaired retention.     

Beta-blockade of morphine-induced hyperlactacidemia in rabbits.

In morphinized rabbits blood lactate levels are elevated. Hyperlactacidemia persists after cessation of morphine injections. This morphine-induced lactate accumulation is completely abolished by simultaneous propranolol treatment. Phentolamine does not modify the action of morphine.     

β-Blockade of morphine-induced hyperlactacidemia in rabbits

Summary In morphinized rabbits blood lactate levels are elevated. Hyperlactacidemia perists after cessation of morphine injections. This morphine-induced lactate accumulation is completely abolished by simultaneous propranolol treatment. Phentolamine does not modify the action of morphine.ERA CNRS No. 412.Acknowledgement. The authors express their appreciation to MissD. Abadie for her help with the lactate determinations.     

Effet des analgésiques non narcotiques sur l'hypotension due à la bradykinine

Summary Hypotension, induced by intravenous injections of bradykinin in the rabbit, was studied after nontoxic doses of non-narcotic analgesics and other drugs. Non-narcotic analgesics accelerated the speed of return to 50% normal blood pressure, whereas morphine, cyproheptadine, dexamethasone and hydrocortisone had no effect. Phentolamine-treated animals reacted similarly. This acceleration appears to be due to a specific antagonism of the non-narcotic analgesics and not to a liberation of adrenalin.     

SONOS自持半导体存储器:记忆时间可靠性与低编程电压

降低编程电压，同时仍保持十年的数据记忆时间，一直是多晶硅－氧化硅－硅（SONOS）研究人员面临的一个巨大挑战。本文介绍SONOS可自持存储器器件设计和降低编程电压方面的进展，硅－氧化硅界面态的退化损害SONOS自持半导体存储器记忆时间和长期可靠性。首次应用在SONOS器件制作工艺上的双步高温氘退火技术，与传统的氢退火相比，显著提高了器件的耐久性能和记忆时间可靠性。我们研制成功－9伏／＋10伏（1毫秒）可编程SONOS存储器，在摄氏85度，一千万个擦除／写入操作后，仍能确保十年的记忆时间，本文介绍编程电压降低方面的设计考虑，制作工艺的优化，描述实验过程和SONOS器件的测试，以及用于SONOS自持存储器动态性能测试的基于可编程门阵列的测量系统。     

Effect of chronic administration of morphine on primary immune response in mice

Summary The effect of 3 different doses of chronically-administered morphine on the primary immune response was studied in mice by estimating spleen/body weight ratio and serum hemolysin production against sheep red blood cells (SRBC). It was observed that morphine exerted a dose-dependent inhibitory effect on the immune response which was antagonized by the concomitant administration of naloxone. The findings suggest that the inhibitory effect of morphine is specific.     

Endocannabinoids and β-amyloid-induced neurotoxicity in vivo: effect of pharmacological elevation of endocannabinoid levels

We investigated the involvement of endocannabinoids in the control of neuronal damage and memory retention loss in rodents treated with the β-amyloid peptide (1–42) (BAP). Twelve days after stereotaxic injection of BAP into the rat cortex, and concomitant with the appearance in the hippocampus of markers of neuronal damage, 2-arachidonoyl glycerol, but not anandamide, levels were enhanced in the hippocampus. VDM-11 (5 mg/kg, i.p.), an inhibitor of endocannabinoid cellular reuptake, significantly enhanced rat hippocampal and mouse brain endocannabinoid levels when administered sub-chronically starting either 3 or 7 days after BAP injection and until the 12–14th day. VDM-11 concomitantly reversed hippocampal damage in rats, and loss of memory retention in the passive avoidance test in mice, but only when administered from the 3rd day after BAP injection. We suggest that early, as opposed to late, pharmacological enhancement of brain endocannabinoid levels might protect against β-amyloid neurotoxicity and its consequences. Received 26 January 2006; received after revision 24 March 2006; accepted 12 April 2006     

Morphine 6 glucuronide stimulates nitric oxide release in mussel neural tissues: evidence for a morphine 6 glucuronide opiate receptor subtype

We have previously demonstrated that Mytilus edulis pedal ganglia contain opiate alkaloids, i.e., morphine and morphine 6 glucuronide (M6G), as well as mu opiate receptor subtype fragments exhibiting high sequence similarity to those found in mammals. Now we demonstrate that M6G stimulates pedal ganglia constitutive nitric oxide (NO) synthase (cNOS)-derived NO release at identical concentrations and to similar peak levels as morphine. However, the classic opiate antagonist, naloxone, only blocked the ability of morphine to stimulate cNOS-derived NO release and not that of M6G. CTOP, a mu-specific antagonist, blocked the ability of M6G to induce cNOS-derived NO release as well as that of morphine, suggesting that a novel mu opiate receptor was present and selective toward M6G. In examining a receptor displacement analysis, both opiate alkaloids displaced [³H]-dihydromorphine binding to the mu opiate receptor subtype. However, morphine exhibited a twofold higher affinity, again suggesting that a novel mu opiate receptor may be present. Received 1 November 2001; received after revision 1 February 2002; accepted 1 February 2002     

Role of the Raphe Magnus nucleus in morphine analgesia : studies with intracerebral microinjections in the rat]

Microinjections of low concentration of morphine (5 micrograms) into the nucleus Raphé Magnus of the Rat produce a strong analgesia that can be reversed by systemic naloxone, an opiate antagonist. The administration of naloxone (5 micrograms) into the Raphé Magnus considerably reduces the effects of intravenous morphine. The effects of microinjections of morphine are strongly reduced by Cinanserin, suggesting a role for serotoninergic mechanisms in morphine analgesia.     

Morphine eye-drops reduce homatropine induced mydriasis in man

Summary In 7 healthy volunteers 4% morphine eye-drops, when administered to one eye, caused a miosis limited to that eye. In 7 other healthy volunteers morphine was administered into one eye after bilateral instillation of 0.5% homatropine opthalmic drops; the eye treated with morphine and homatropine showed a mydriasis less intense than the other eye treated only with homatropine. It is suggested that topical morphine locally affects sympathetic function by inhibiting noradrenaline release into the iris neuromuscular junction.This work was partly supported by the CNR study group Pain Control. The authors wish to thank Dr Tendi of the Pharmacy of St. Maria Nuova Hospital, Florence, for the preparation of the eye-drops.     

The effects of acute and chronic morphine on regional distribution of cardiac output in brain

Both acute and chronic administration of morphine resulted in an increase in the percent cardiac output received by brain. However, various brain regions were affected differently by the drug treatments. The greatest increases in percent cardiac output received after chronic administration of morphine occurred in pons and cerebellum, while the greatest increases after acute administration occurred in cortex and midbrain. The changes found are in contrast with earlier studies which suggest that morphine has no effect on cerebral blood flow.     

Aggressive behaviour induced by marihuana compounds and amphetamine in rats previously made dependent on morphine

Résumé Les rats soumis à la morphine ont été traités pendant la phase d'abstinence avec des injections i.p. d'amphéta mine et (–) ⁹-trans-tätrahydrocannabinol.

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With a fellowship from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). We are very grateful to Prof.J. Ribeiro do Valle, Escola Paulista de Medicina, for the generous supply of THC.     

Recherches sur les variations de la densité des microorganismes dans le colon du Lapin domestique

Summary In the rabbit, during the excretion of day faeces, 71% of the microorganisms disappear along the colon. This phenomenon reaches a maximal intensity at the proximal colon level. Though the nature of this process is unknown, we may affirm that an important retention of proteins for the host is thus achieved.     

基于B超图像的HIFU运动控制系统位移标定

针对目前高强度聚焦超声（HIFU）治疗中运动控制系统与B超图像之间的位移标定准确度不高的问题,基于B超图像的亚像素级配准算法,研究组合探头运动时靶区组织的实际位移与B超图像中像素位移之间的映射关系并进行标定,以提高对靶区组织B超定位的准确性,帮助HIFU临床医生更加有效地对靶区组织进行治疗。     

Prolactin and growth hormone releasing activity of [D-Met2, Pro5]-enkephalinamide in the rat after systemic administration

Summary The growth hormone (GH) and prolactin releasing (PRL) activity of [D-Met², Pro⁵]-enkephalinamide (EKNH₂), an opioid peptide analog with higher opiate agonist activity that morphine, was compared in the unanesthetized male rat to those of equimolar doses of morphine upon systemic injection. EKNH₂ proved to be a higher PRL, but not GH, releaser than the opiate alkaloid.     

Morphine suppression of ethanol withdrawal in mice

Summary The acute administration of morphine, alcohol or dopamine results in a pronounced suppression of the convulsions produced by alcohol in mice. The suppressive action of morphine on alcohol withdrawal in the mouse apparently is not a product of morphine intoxication, but rather to some other specific interaction between alcohol and morphine in the central nervous system. The conclusion suggest that dopamine may play a significant role as a modulator in convulsions produced during alcohol withdrawal.Dr.Kenneth Blum is Associate Professor in Pharmacology at The University of Texas Health Science Center at San Antonio and a Career Teacher in Drug Abuse and Alcoholism under a grant number 1-TO1-DA00290-01 from the National Institute on Drug Abuse.Acknowledgments. Our thanks are due toB. Wiggins, R. Marin andS. Elston for their excellent technical assistance. Research funded in part by Air Force Grant No. AFOSR-71-2075.     

Effects of morphine administration on cerebellar guanosine 3′,5′-monophosphate

Summary An increase in mouse cerebellar C-GMP levels, during acute morphine treatment was observed, which was possibly related to the decrease in C-GMP phosphodiesterase levels also observed in acute treatment. Chronic treatment lowered C-GMP levels as did abrupt withdrawal without naloxone.     

Effects of morphine administration on cerebellar guanosine 3',5'-monophosphate.

An increase in mouse cerebellar C-GMP levels during acute morphine treatment was observed, which was possibly related to the decrease in C-GMP phosphodiesterase levels also observed in acute treatment. Chronic treatment lowered C-GMP levels as did abrupt withdrawal without naloxone.     

Comparative activity of endorphins on the opiate receptors]

Displacement of naloxone from membranes of Rat brain by alpha, beta and gamma-endorphins with and without Na+ in the incubating medium has been studied. beta-endorphin shows a higher affinity for the opiate receptors and a stronger agonist property than morphine. alpha and gamma-endorphins have a much lower affinity than morphine and a marked antagonist characteristic. This study suggests the possibility of naturally occurring antagonists of the opiate receptors.     

Effects of d1-methadone and morphine on developing chick embryo

Summary Injections of methadone into the air space of fertile chicken eggs affected development of the embryo. Both methadone and morphine caused decreases in liver weight and brain protein, and morphine increased liver protein levels.Acknowledgment. We thank E. Sutherland for technical assistance. Supported by a grant from the Department of Health and Welfare, Canada, and the British Columbia Ministry of Health, Alcohol and Drug Commission.