Effect of Extracts from Carissa Carandas Leaves on Cognitive Performance in Morris Water Maze in mice.

1995 ◽  
Vol 120 (4) ◽  
pp. 409-417 ◽  
Author(s):  
D. J. Fontana ◽  
S. E. Daniels ◽  
C. Henderson ◽  
R. M. Eglen ◽  
E. H. F. Wong

2021 ◽  
Vol 8 ◽  
Author(s):  
DongSheng Bian ◽  
Xinyue Wang ◽  
Jiale Huang ◽  
Xiaoxuan Chen ◽  
Hongwei Li

Sialic acids are postulated to improve cognitive abilities. This study aimed to evaluate the effects of sialic acid on behavior when administered in a free form as N-acetylneuraminic acid (Neu5Ac) to pregnant mothers or rat pups. The experiment involved 40 male 21-day-old rat pups and 20 15-day-pregnant rats that were randomized into four Neu5Ac treated groups: 0 (control), or 10, 20, and 40 mg/kg. Morris water maze test and shuttle box test were performed on the rat pups and maternal Neu5Ac-supplemented offspring on day 100 to evaluate their cognitive performance. The Neu5Ac levels in the cerebral cortex and hippocampus were tested with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). We found that the maternal Neu5Ac-supplemented offspring showed better cognitive performance, less escape latency in the Morris water maze test, and less electric shock time shuttle box test, compared with the untreated control. In the meantime, the Neu5Ac level in the cerebral cortex and hippocampus of the offspring was higher in the Neu5Ac treatment group than that in the untreated control group. However, no significant differences were observed between rat pups in the treated and the untreated control groups in terms of cognitive performance and Neu5Ac content in the cerebral cortex and hippocampus. Maternal Neu5Ac supplementation during pregnancy could effectively promote the brain Neu5Ac content of the offspring and enhance their cognitive performance, but Neu5Ac had no such effect on rat pups while directly supplemented with Neu5Ac.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vasiliy V. Reshetnikov ◽  
Polina E. Kisaretova ◽  
Nikita I. Ershov ◽  
Anastasia S. Shulyupova ◽  
Dmitry Yu. Oshchepkov ◽  
...  

AbstractLearning and memory are among higher-order cognitive functions that are based on numerous molecular processes including changes in the expression of genes. To identify genes associated with learning and memory formation, here, we used the RNA-seq (high-throughput mRNA sequencing) technology to compare hippocampal transcriptomes between mice with high and low Morris water maze (MWM) cognitive performance. We identified 88 differentially expressed genes (DEGs) and 24 differentially alternatively spliced transcripts between the high- and low-MWM-performance mice. Although the sets of DEGs and differentially alternatively spliced transcripts did not overlap, both were found to be enriched with genes related to the same type of biological processes: trans-synaptic signaling, cognition, and glutamatergic transmission. These findings were supported by the results of weighted-gene co-expression network analysis (WGCNA) revealing the enrichment of MWM-cognitive-performance-correlating gene modules with very similar Gene Ontology terms. High-MWM-performance mice manifested mostly higher expression of the genes associated with glutamatergic transmission and long-term potentiation implementation, which are processes necessary for memory acquisition and consolidation. In this set, there were genes participating in the regulation of trans-synaptic signaling, primarily AMPA receptor signaling (Nrn1, Nptx1, Homer3, Prkce, Napa, Camk2b, Syt7, and Nrgn) and calcium turnover (Hpca, Caln1, Orai2, Cpne4, and Cpne9). In high-MWM-performance mice, we also demonstrated significant upregulation of the “flip” splice variant of Gria1 and Gria2 transcripts encoding subunits of AMPA receptor. Altogether, our data helped to identify specific genes in the hippocampus that are associated with learning and long-term memory. We hypothesized that the differences in MWM cognitive performance between the mouse groups are linked with increased long-term potentiation, which is mainly mediated by increased glutamatergic transmission, primarily AMPA receptor signaling.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Mohamed ElSaadani ◽  
Syed M. Ahmed ◽  
Christina Jacovides ◽  
Alfonso Lopez ◽  
Victoria E. Johnson ◽  
...  

Author(s):  
Е.И. Захарова ◽  
З.И. Сторожева ◽  
А.Т. Прошин ◽  
М.Ю. Монаков ◽  
А.М. Дудченко

Цель - исследование холинергической синаптической организации функций обучения и памяти у крыс с разными когнитивными способностями. Методы. Крыс обучали на пространственной обстановочной модели в водном лабиринте Морриса. Через 2-3 сут. после окончания тренировок животных декапитировали, из неокортекса и гиппокампа с помощью центрифугирования выделяли субфракции синаптических мембран и синаптоплазмы легких и тяжелых синаптосом. В синаптических субфракциях определяли активность ключевого фермента холинергических нейронов холинацетилтрансферазы (ХАТ). Сравнивали результаты тестирования (время достижения скрытой платформы) и активность фермента у способных и неспособных к обучению крыс. Результаты. Были выявлены: 1) различия в холинергической организации исследованных функций в процессе обучения у способных и неспособных к обучению крыс, в том числе: положительные корреляции активности ХАТ в синапсах проекционных нейронов неокортекса у способных крыс со временем достижения платформы на промежуточных этапах обучения и в синапсах проекционных нейронов гиппокампа у неспособных крыс на позднем этапе обучения; разнонаправленные корреляции активности ХАТ в синапсах, предположительно, интернейронов гиппокампа (фракция тяжелых синаптосом) у способных и неспособных крыс на начальном и позднем этапах обучения; 2) индивидуальность холинергической организации функций на всех этапах обучения. Выводы. Полученные данные свидетельствуют в пользу представлений о специфике холинергической организации функций пространственного обстановочного обучения у крыс с выраженными и слабыми способностями к обучению, а также избирательной роли холинергических интернейронов гиппокампа на исходном этапе обучения и в консолидации памяти. In order to expand the knowledge about neuronal organization of the cognitive functions required for understanding plastic processes in the brain, we investigated the cholinergic synaptic organization of learning and memory functions in rats with different cognitive abilities. Methods. Rats were trained on a contextual situation model in the Morris water maze. At 2-3 days after the end of training, animals were decapitated, and subfractions of synaptic membranes and synaptoplasm of light and heavy synaptosomes were isolated from the cortex and the hippocampus by centrifugation. In synaptic subfractions, activity of the key enzyme of cholinergic neurons, choline acetyltransferase, was measured. We compared the test results (latent period to reach the hidden platform) and the enzyme activity in capable (lower quartile) and incapable of learning rats (upper quartile). Results. The following was found: 1) differences in the cholinergic organization of studied functions in capable and uncapable of learning rats during training, including: positive correlations of choline acetyltransferase activity in synapses of projection neurons in the cortex of capable rats with latency to reach the platform at intermediate stages of training and in the hippocampus ofincapable rats at late stages of training; multidirectional correlations of choline acetyltransferase activity in synapses of hippocampal, presumably, interneurons (heavy synaptosomes) in capable and incapable rats at early and late stages of training; 2) distinctness of the cholinergic organization of functions at all stages of training. Conclusions. The study demonstrated for the first time a specificity of the cholinergic organization of functions in spatial situational learning of rats with strong and poor learning abilities and a selective role of hippocampal cholinergic interneurons at the initial stage of learning and in memory consolidation.


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