Effects of Rimonabant on learning and memory of rats with olfactory bulbectomy

Olfactory bulbectomy (OBX) is an experimental model of depression, which has recently been used as a model of Alzheimer's disease due to the development of neurodegenerative changes in the brain. The OBX model in rodents is accompanied by biochemical, morphological and structural changes in the brain, as well as by many behavioral changes. A common finding in the OBX model are memory deficits, which are present in both depressive disorders and neurodegenerative diseases. There is evidence that the memory-impairing effect of cannabinoids is associated with activation of the cannabinoid CB1 receptors in the brain. The aim of the present study was to investigate the effects of the CB1 antagonist Rimonabant (SR 141716A) administered intragastrically daily for 14 days on the memory processes of OBX rats, tested in a passive avoidance (PA) paradigm. Rimonabant was administered to OBX rats, divided into three experimental groups: before OBX; immediately after OBX (1-14 days); with the presence of a depressive-like state (14-28 days after OBX).  Rimonabant showed a tendency to improve the learning and memory of sham-operated controls, whereas no significant change in the behavioral responses was observed upon administration 14 days before OBX. However, Rimonabant, administered immediately after OBX completely prevented the development of memory deficit in a PA test, while its administration 14-28 days after OBX ameliorated the memory disturbances induced by bulbectomy.The results indicate that the CB1 antagonist Rimonabant may ameliorate the development of a memory deficit in OBX rats

Wine as a medicine in ancient times

The history of wine use as a medicine dates back to antiquity. However, it has been rediscovered and reliably confirmed by current medical research. It is believed that wine is among the first documented remedies known and used by humans dating back to a period before 5000 BC. Preserved to date evidence of the medical use of wine in ancient times is very limited and is related to the development of different cultures and ancient civilizations. The article chronicles the more important periods of the history of the use of wine for medical (healing and prophylactic) purposes.The first evidence dates back to the time of the Mesopotamian culture, when the world's oldest Sumerian Pharmacopoeia - clay tiles, some of which contain wine prescriptions for therapy, was created. The next important documentary evidence is found in the Sino-Tibetan Pharmacopoeia, the Egyptian Medical Papyri, the Bible, the Sacred Book of the Jews Talmud, and the ancient Indian medical texts of Ayurveda. In ancient Greece, the first evidence of the healing effects of wine is found in the two poems of Homer Iliad and Odyssey. With the development of medical knowledge at the time of Hippocrates, the therapeutic use of wine expanded. Hippocrates included wine in the diet of almost all diseases, especially during the recovery period. Afterwards, the principles of wine therapy continued to be topical, although they were the subject of a heated debate during the Greco-Roman period, Galen's era, and even the Byzantine era, when the influence of Arab medicine began to manifest itself more and more

Neurophysiological mechanisms of sweet taste preference

Food intake regulation is a complex process influenced by the dynamic interplay between two systems—homeostatic and hedonic regulation systems. Homeostatic regulation depends on the information from the gastrointestinal tract, adipose tissue, n. vagus, while hedonic regulation is primarily controlled by reward processes. This is multifactor process that creates and establishes specific patterns of eating behavior, often associated with certain taste preferences

Influence of the endocannabinoid system on memory processes

The endocannabinoid system (ECS) is a lipid signaling system, which consists of the endocannabinoids (EC) anandamide (AEA) and 2-arachidonylglycerol (2-AG), the cannabinoid receptors (CB1 and CB2), and the enzymes that regulate their production and degradation. AEA and 2-AG are lipid compounds derived presynaptically from the degradation of membrane phospholipids and act as key modulators on synaptic transmission. This article presents accumulated data on the mechanisms by which ECS affects learning and memory. Substances that modulate the activity of ECS have impact on different phases of memory formation through direct and indirect influences. Studies show contradictory results on the role of the ECS in learning and memory processes

MODULATORY EFFECT OF CANNABINOID LIGANDS ON THE ANXIETY-LIKE BEHAVIOR OF BULBECTOMIZED RATS

Purpose: The endocannabinoid system is considered a key regulatory system in anxiety behavior. The aim of the present study was to examine the effects of intracerebroventricularly (i.c.v.) injected cannabinoid ligands on the anxiety-like behavior of rats with a model of depression. Material/Methods: The olfactory bulbectomized rat (OBX) is a well-established experimental model of depression. The OBX model exhibits neurochemical changes that are very similar to those seen in patients with depression. CB1 receptor agonist HU-210 and CB1 receptor antagonist SR 141716A were injected i.c.v. in OBX rats, and the anxiety-related behavior of the rats was measured in an elevated plus-maze (EPM) test. Results: OBX rats showed an increased anxiety-like behavior at the EPM test. HU-210 produced an anxiolytic-like effect and alleviated the OBX-induced anxiety, while SR 141716A failed to produce effects on the behavior of OBX rats. Conclusions: The results suggest that CB1 receptors may be involved in the modulation of anxiety-related behavior in OBX rats

Imprinting: nature and manifestations in humans

Imprinting (filial and sexual) is a process of learning a key stimulus or complex stimuli during early critical periods of development, further determining the implementation of innate forms of behavior. The present literature review summarizes earlier and current data regarding the neurophysiology and neurochemistry of imprinting, and its potential benefits. Although, according to the classic views, imprinting is inherent in birds and some mammals, there are reasons to assume that imprinting or similar forms of learning also exist in humans. In the context of this assumption, the mechanisms of newborn-mother bonding and of assortative mate choice in humans are discussed

Influence of Subchronically Applied Ligands on the Cannabinoid Receptors on Learning and Memory Processes in Olfactory Bulbectomized Rats // Влияние на субхронично въвеждани лиганди на канабиноидните рецептори върху обучителните и паметови процеси на плъхове с олфакторна булбектомия

The main task of the present study is, by using various ways of applications: i.c.v. and intragastric, in the conditions of the subchronic experiment (7 and 14 days), to evaluate the effects of ligands on cannabinoid receptors on learning and memory processes in rats with OBX-model. Based on the results of our study, we can conclude that the investigation of the influence of subchronically applied ligands of cannabinoid receptors in rats with a model of olfactory bulbectomy is a specific contribution to revealing the role of CB-receptors in the development of memory deficits, accompanying this model. Comparing the effects in OBX- and Sham-operated rats allows a distinct evaluation of the physiologic importance of the CB-receptors for the cognitive processes in the organism. The results and conclusions underline the necessity of accumulating more data for the effects and investigation of the ECS manipulation in specific conditions, thus widening the potential therapeutic approach to treat depression and Alzheimer’s disease. The study presents additional details on the interrelation between the cognitive and depressive symptoms and the ECS influence on cognitive and emotional processes with pathologic disorders accompanied by a cognitive effect, like depression, Alzheimer’s disease, etc.Основната задача на настоящото изследване е чрез използване на различни начини на субхронично приложение: i.c.v. и интрагастрално (7 и 14 дни), да се оценят ефектите на лигандите на канабиноидните рецептори върху процесите на обучение и памет при плъхове с OBX-модел. Въз основа на цялото изследване можем да обобщим, че проучването на влиянието на субхронично въвежданите лиганди на канабиноидните рецептори на плъхове с модел олфакторна булбектомия, допринася за разкриване ролята на СВ-рецепторите в развитието на паметовите дефицити, съпътстващи модела. Сравняването на ефектите на OBX- и Sham-оперирани плъхове позволява да се оцени физиологичното значение на CB-рецепторите за когнитивните процеси. Резултатите и заключенията подчертават необходимостта от натрупване на повече данни за ефектите от манипулирането на ендоканабиноидната система при специфични условия, като по този начин би могъл да се разшири потенциалният терапевтичен подход за лечение на депресията и болестта на Алцхаймер. Изследването представя детайли за изясняване на взаимовръзката между когнитивните и депресивните симптоми, както и по отношение на ендоканабиноидното влияние върху когнитивните и емоционални процеси при заболявания, като депресия и болест на Алцхаймер