Effects of training in the Morris water maze on the spatial learning acquisition and VAChT expression in male rats

"n  "n  Background and the purpose of the study: It has been well established that cholinergic pathway plays an important role in learning and memory processes. The present study was designed to evaluate the effects of Morris water maze (MWM) training on spatial memory acquisition and expression of the vesicular acetylcholine transporter (VAChT) in male rats. "n  Methods: In this study, training trials of all groups of animals were conducted in the MWM task. Rats received one training session consisting of four trials per day which continued for another four consecutive days. Controls received visible platform MWM training. The escape latency, the traveled distance and swimming speed for each rat were recorded and used to evaluate the performance of the animal during training period. For evaluation of expression of VAChT protein levels, brain tissues from animals in each experiment were obtained immediately after the last trial on the related experimental day and processed for immunohistochemistry staining and western blotting analysis. "n  Results: There was a significant difference between animals subjected to one day training and those receiving four days of training in escape latency and travel distance. There were an apparent increase in VAChT immunoreactivity in the medial septal area (MSA) and CA1 region of the hippocampus in one day and four day trained animals compared with controls (visible group). Quantitative immunostaining analysis by optical density measurements in the CA1 region and evaluation of immunopositive neurons in medial septal area of brain sections confirmed qualitative findings. Assessment of VAChT protein level expression in hippocampus by western blotting evaluation showed the same pattern of immunohistochemistry results. "n  Conclusion: Overall, results of this study reveal changes in cholinergic neuron activity in different stages of training in the MWM task. Data suggest that there is a significant level of cholinergic neuronal activity during early stages of the training especially in the hippocampus region that may contribute to the apparent increase in VAChT expression

Prolonged maternal separation induces undernutrition and systemic inflammation with disrupted hippocampal development in mice

Objective: Prolonged maternal separation (PMS) in the first 2 wk of life has been associated with poor growth with lasting effects in brain structure and function. This study aimed to investigate whether PMS-induced undernutrition could cause systemic inflammation and changes in nutrition-related hormonal levels, affecting hippocampal structure and neurotransmission in C57BL/6J suckling mice. Methods: This study assessed mouse growth parameters coupled with insulin-like growth factor-1 (IGF-1) serum levels. In addition, leptin, adiponectin, and corticosterone serum levels were measured following PMS. Hippocampal stereology and the amino acid levels were also assessed. Furthermore, we measured myelin basic protein and synapthophysin (SYN) expression in the overall brain tissue and hippocampal SYN immunolabeling. For behavioral tests, we analyzed the ontogeny of selected neonatal reflexes. PMS was induced by separating half the pups in each litter from their lactating dams for defined periods each day (4 h on day 1, 8 h on day 2, and 12 h thereafter). A total of 67 suckling pups were used in this study. Results: PMS induced significant slowdown in weight gain and growth impairment. Significant reductions in serum leptin and IGF-1 levels were found following PMS. Total CA3 area and volume were reduced, specifically affecting the pyramidal layer in PMS mice. CA1 pyramidal layer area was also reduced. Overall hippocampal SYN immunolabeling was lower, especially in CA3 field and dentate gyrus. Furthermore, PMS reduced hippocampal aspartate, glutamate, and gammaaminobutyric acid levels, as compared with unseparated controls. Conclusion: These findings suggest that PMS causes significant growth deficits and alterations in hippocampal morphology and neurotransmission.This work was supported in part by National Institutes of Health (NIH) research grant 5R01HD053131, funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the NIH Office of Dietary Supplements, and Brazilian grants from CNPq and CAPES (Grant # RO1 HD053131). The authors would like to thank Dr. Patricia Foley for veterinarian technical support and Dr. Jose Paulo Andrade for the excellent comments and suggestions to improve this manuscript. N.S. contributed with the stereological studies. I.L.F. and R.B.O. contributed with the behavioral studies. I.L.F., R.B.O., and R.L.G. contributed with the study design, study analysis, and manuscript preparation. G.A.M. and P.B.F. contributed with neurochemical brain analyses. J.I.A.L. and G.M.A. contributed with hormonal and CRP serum analyses. D.G.C., K.M.C., and R.S.R. contributed with animal experimentation and data collection

Beneficial effect of Boswellia serrata gum resin on spatial learning and the dendritic tree of dentate gyrus granule cells in aged rats

Objective: The hippocampal formation, particularly the dentate gyrus (DG), shows age-related morphological changes that could cause memory decline. It is indicated that Boswellia resins attenuates memory deficits and the major component of Boswellia serrata (Bs) gum resin, beta boswellic acid increased neurite outgrowth and branching in hippocampal neurons. This study was designed to investigate the effect of Boswellia treatment on spatial learning performance and the morphology of dentate granule cells in aged rats. Materials and Methods: Sixteen male Wistar rats (24 months old) were divided into experimental and control groups. Experimental group was intragastrically administered with the aqueous extract of Bs (100 mg/kg/d for 8 weeks) and control group received a similar volume of water. Spatial learning performance of rats was tested using Morris water maze task. At the end of experiment, the brain was removed and the right hippocampus was serially sectioned for morphometric analysis. The Cavalieri principle was employed to estimate the volume of the DG. A quantitative Golgi study was used to analyze the dendritic trees of dentate granule cells. Results: Chronic treatment with Bs improved spatial learning capability during the three acquisition days. Comparisons also revealed that Bs-treated aged rat had greater DG with increased dendritic complexity in the dentate granule cells than control rats. Hippocampal granule cells of Bs-treated aged rats had more dendritic segments, larger arbors, more numerical branching density and more dendritic spines in comparison to control animals. Conclusion: This study provided a neuro-anatomical basis for memory improvement due to chronic treatment with Bs

A Morphometeric Study on CA3 Hippocampal Field in Young Rats Following Maternal Administration of Boswellia Serrata Resin During Gestation

Abstract Objective It has previously been shown that prenatal maternal administration of Boswellia serrata gum resin (Frankincense) improved learning and memory performance associated with an increase in the size of neuronal bodies in CA3 (Cornu Ammonis) of hippocampus. Continuing the previous work, a morphometric study was designed on CA3 field to examine precisely the effect of prenatal administration of frankincense on the structure of this region. Materials and Methods 2 months-old male Wistar rats whose mothers were given orally the aqueous extract of the Boswellia serrata (0.1 g/kg/day) during gestation (3 weeks) were anesthetized and transcardially perfused with phosphate-buffered solution of 4% formaldehyde and 1% glutaraldehyde (n=8). Each brain was removed and divided into two hemispheres. One hemisphere selected at random for estimating the volumes of CA3 layers, and the other for morphometeric analysis of CA3 neuronal dendrites. The Cavalieri principle employed to estimate the volumes and a quantitative Golgi study used to analyse the dendritic arborizations. Results Comparisons revealed that the control rats had lower volumes than the experimental animals in all layers of CA3 (p<0.05). It was also indicated that the neurons of CA3 in experimental rats had more dendritic segments (31.25±3.33) than the controls (27.5±2.67), p<0.05. The dendritic branching density was higher in experimental rats relative to that found in the control rats. Conclusion Results of this study provide a neuroanatomical basis that may be relevant to the early reported enhancement of learning and memory abilities in offspring

Using Surface Anatomy in Teaching The Anatomy of Upper Limb Vessels to Students of Allied Health Sciences

Introduction: Despite the abundant studies on teaching anatomy using cadaver, a few studies have documented the use of surface anatomy. Also, the majority of articles concerning human anatomy teaching have focused on medical student education and less attention has been paid to teaching anatomy to students of allied health sciences. Therefore, this study aimed to investigate the effect of teaching of upper limb vessels anatomy using surface anatomy on the anatomy knowledge of first year students of allied health sciences in Shahid Sadoughi University of Medical Sciences and their viewpoints on this teaching method. Methods: This quasi-experimental study was performed on all students of radiology (N=33) and anesthesia technology (N=27) admitted in year 2010. Students were randomly divided into two experiment (30 individuals with surface anatomy method) and control (30 individuals with traditional method). In the experiment group, through the assistance of an instructor, students examined the surface landmarks of upper limb vessels in one of their peers. The traditional anatomy education was performed by didactic lectures using PowerPoint slide shows. At the end of course, through an exam, mean of students’ scores were compared between groups. The viewpoints of the students on surface anatomy teaching method in the experiment group were assessed by a valid and reliable questionnaire. Data were analyzed using descriptive statistics and Student t-test. Results: Mean of exam scores in the experiment group (13.8± 4.9) and was significantly (t=2.165, P=0.034) more than in the control (10.8± 6.2). IN experiment group, most (67%) of the students had a positive viewpoint on surface anatomy education 57% rated surface anatomy teaching as a very interesting method, and 47% noticed that the surface anatomy of upper limb vessels enhanced their skill for future clinical practice. Conclusion: The results showed that after teaching, compared to the control group, students' knowledge was more in the experiment group. Most students in the experiment group had positive attitude toward the teaching method applied. Therefore, the use of surface anatomy as a part of teaching anatomy in schools of allied health sciences is suggested

Stereological analysis of cornu ammonis in prenatally stressed rats: a heuristic neurodevelopmental model of schizophrenia

Objective(s):The hippocampus has been implicated in pathophysiology of schizophrenia. Prenatal stress is a contributing risk factor for a wide variety of neuropsychiatric diseases including schizophrenia. This study examined long-term effects of prenatal restraint stress on the stereological parameters in the Cornu Ammonis (CA) of adult male rats as an animal model of schizophrenia. Materials and Methods:Wistar pregnant dams in experimental group were stressed in a cylindrical Plexiglas restrainer daily for 1 hr during last week of gestation. Controls remained in the animal room and were exposed only to normal animal room conditions. At 2 months of age, the volume of the pyramidal cell layer of the CA, the numerical density and the somal volume of the respective neurons were assessed in the male offspring generated from stressed and control pregnancies. Cavalieri's principle, physical disector and nucleator were applied for stereological analyses. Results:This study showed that prenatal stress significantly decreased the volume of CA3 pyramidal cell layer and the individual somal volume of CA3 pyramidal neurons. However, there were no markedly differences in the numerical density, total number of CA3 pyramidal neurons and stereological parameters in CA1 of prenatally stressed and control animals. Conclusion: These data indicate that prenatal stress exposure induced neuronal changes in the CA3 subfield of hippocampus which are similar to what is observed in schizophrenia