bibi zahra javadmoosavi

Sleep disorder or sleep deprivation (SD) is a common issue in today’s society. Numerous evidences show that sleep is essential for proper brain performance and cognitive processes; on the other hand, cognitive functions have a broad range with learning and long-term memory as the most important ones related to attention. Since many studies show that cholinergic system has a significant role in sleep, learning, and memory, this study aims to investigate the impacts of CA1 Cholinergic Nicotinic Receptors on memory acquisition deficit which is stimulated by total sleep deprivation (TSD) and REM sleep deprivation (RSD).
In this study a water box or a multi-platform apparatus was used in order to induce total sleep deprivation (TSD) or REM sleep deprivation (RSD). In order to investigate interactions of cholinergic system and hippocampus-dependent memory, nicotinic receptor agonist (nicotine) or nicotinic receptor antagonist (mecamylamine) was injected in hippocampal CA1.
According to the results of this study, 24 hours TSD or RSD decreased memory acquisition and injection of nicotine (0.0001 or mecamylamine (0.001 in TSD and RSD sham groups didn’t change memory acquisition. However, injection of sub-threshold dose of nicotine (0.0001 and mecamylamine (0.001 could reduce negative effects of SD in both TSD and RSD.
Discussion; According to the present study, cholinergic nicotinic receptors are effective in learning and memory improvement.

More than sixty one substances have been found in Cannabis sativa which are called cannabinoids. Cannabinoids are involved in all stages of memory.The aim of this study was to evaluate the effects of leaves aquatic extract of Cannabis sativa on the neuronal density of CA1, CA2 and CA3 of Hippocampus in rats.

In this experimental study twenty four male Wistar rats (weight 300-350 g) were divided into two experimental and one control groups. Cannabis sativa was extracted with Soxhlet apparatus. Aquatic extract was injected introperitonealy (I.P.) in experimental groups with two dosages (50 mg/kg and 25 mg/kg) for three weeks. After one month, animals were decapitated and their brains were dissected, fixed in 10% formalin, sectioned in 7μm thickness and stained by hematoxin-eosin (HE). By applying dissector techniques and systematic random sampling scheme the neuronal density of CA1, CA2 and CA3 of Hippocampus were estimated. Then, the numerical density in each group compared with control group using t-test and ANOVA statistics and Tukey test by Minitab 13 software.

Neuronal density average of CA1 area in control, experimental 1 and 2 groups were 37396±553, 10081±233 in CA1 and 10986±382, CA2 area 33045±449, 14648±284 and 17147±378 and in CA3 area 26324±437, 10469±215 and 13829±359 respectively. Statistical analyses showed significant decrease (P<0.001) in the CA1, CA2 and CA3 of Hippocampus neuronal density in experimental groups compared to control group.

Aquatic extract of Cannabis sativa leaves has canabinoids substances that may effectively increase dopamine release and inhibit the production of impulse and induce neuronal degeneration in Hippocampus leading to reduction of the neuronal density of Hippocampus.