Corrigendum to: Neuroprotection by Human Dental Pulp Mesenchymal Stem Cells: From Billions to Nano.

In this correction, the Editor in Chief suggested revising the publication of Figures 3 and 8E in the article after the correction in numeric value. Below is the corrected version of the figures [1]. The electronic version of the article can be found in "Neuroprotection by Human Dental Pulp Mesenchymal Stem Cells: From Billions to Nano" in the journal Current Gene Therapy, 2018, 18(5), 307-323. Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused. The original article can be found online at: https://www.eurekaselect.com/article/93056.

Reversal of Neuropsychiatric Comorbidities in an Animal Model of Temporal Lobe Epilepsy Following Systemic Administration of Dental Pulp Stem Cells and Bone Marrow Mesenchymal Stem Cells.

INTRODUCTION: We aim to investigate whether timed systemic administration of dental pulp stem cells (DPSCs) or bone marrow mesenchymal stem cells (BM-MSCs) with status epilepticus (SE) induced blood-brain barrier (BBB) damage could facilitate the CNS homing of DPSCs/BM-MSCs and mitigate neurodegeneration, neuroinflammation and neuropsychiatric comorbidities in an animal model of Temporal Lobe epilepsy (TLE). BACKGROUND: Cognitive impairments, altered emotional responsiveness, depression, and anxiety are the common neuropsychiatric co-morbidities observed in TLE patients. Mesenchymal stem cells (MSCs) transplantation has gained immense attention in treating TLE, as ~30% of patients do not respond to anti-epileptic drugs. While MSCs are known to cross the BBB, better CNS homing and therapeutic effects could be achieved when the systemic administration of MSC is timed with BBB damage following SE. OBJECTIVES: The objectives of the present study are to investigate the effects of systemic administration of DPSCs/BM-MSCs timed with BBB damage on CNS homing of DPSCs/BM-MSCs, neurodegeneration, neuroinflammation and neuropsychiatric comorbidities in an animal model of TLE. METHODOLOGY: We first assessed the BBB leakage following kainic acid-induced SE and timed the intravenous administration of DPSCs/BM-MSCs to understand the CNS homing/engraftment potential of DPSCs/BM-MSCs and their potential to mitigate neurodegeneration, neuroinflammation and neuropsychiatric comorbidities. RESULTS: Our results revealed that systemic administration of DPSCs/BM-MSCs attenuated neurodegeneration, neuroinflammation, and ameliorated neuropsychiatric comorbidities. Three months following intravenous administration of DPSCs/BM-MSCs, we observed a negligible number of engrafted cells in the corpus callosum, sub-granular zone, and sub-ventricular zone. CONCLUSION: Thus, it is evident that functional recovery is still achievable despite poor engraftment of MSCs into CNS following systemic administration.

Neurogenic and cognitive enhancing effects of human dental pulp stem cells and its secretome in animal model of hippocampal neurodegeneration.

Progressive hippocampal neuronal losses, neuroinflammation, declined neurogenesis and impaired hippocampal functions are pathological features of Alzheimer's disease and temporal lobe epilepsy (TLE). Halting neuroinflammation and progressive neurodegeneration in the hippocampus is a major challenge in treating such disease conditions which, if unsuccessful would lead to learning/memory dysfunction and co-morbidities like anxiety/depression. Mesenchymal stem cells (MSCs) therapy provides hope for treating neurodegenerative diseases by either replacing lost neurons by transplantation of MSCs which might differentiate into appropriate neuronal phenotypes or by stimulating the resident neural stem cells for proliferation/differentiation. In this current study, we demonstrate that the intrahippocampal transplantation of ectoderm originated dental pulp stem cells (DPSCs) or intrahippocampal injection of DPSCs condition medium (DPSCs-CM) in a mouse model of hippocampal neurodegeneration could efficiently prevent neurodegeneration, neuroinflammation, enhance hippocampal neurogenesis and spatial learning and memory functions much superior to commonly used bone marrow mesenchymal stem cells (BM-MSCs) or its secretome. Probing the possible mechanisms of neuroprotection revealed that DPSCs/DPSCs-CM treatment upregulated an array of hosts' endogenous neural survival factors expression, reduced pro-apoptotic caspase activity and upregulated the anti-apoptotic factors BCL-2 and phosphorylated PI3K prominently than BM-MSCs/BM-MSCs-CM, suggesting that among MSCs, neural crest originated DPSCs might be a better adult stem cell candidate for treating neurodegenerative diseases.

Efficacy of choline and DHA supplements or enriched environment exposure during early adult obesity in mitigating its adverse impact through aging in rats.

INTRODUCTION: The aim of this study was to assess the efficacy of choline and DHA or exposure to environmental enrichment in obese adult and aging rats on alterations in body mass index, serum lipid profile and arterial wall changes, despite stopping high fat diet consumption and interventions during adulthood. METHODS: 21 day old male Sprague Dawley rats were assigned as Experiment-1 & 2 - PND rats were divided into 4 groups with interventions for 7 months (n = 8/group). NC- Normal control fed normal chow diet; OB- Obese group, fed high fat diet; OB + CHO + DHA- fed high fat diet and oral supplementation of choline, DHA. OB + EE- fed high fat diet along with exposure to enriched environment .Experiment-2 had similar groups and interventions as experiment 1 but for next 5 months were fed normal chow diet without any interventions. Body mass index was assessed and blood was analyzed for serum lipid profile. Common Carotid Artery (CCA) was processed for Haematoxylin and eosin, Verhoff Vangeison stains. Images of tissue sections were analyzed and quantified using image J and tissue quant software. RESULTS: In experiment.1, mean body mass index (p < 0.001), serum lipid profile (p < 0.01), thickness of tunica intima (p < 0.05), tunica media (p < 0.01) and percentage of collagen fibers (p < 0.01) of CCA were significantly increased in OB compared to NC. These were significantly attenuated in OB + CHO + DHA and OB + EE compared to OB. In experiment.2, mean body mass index (p < 0.01), serum lipid profile (p < 0.05) and thickness of tunica media of CCA (p < 0.01) were significantly increased in OB compared to NC. In OB + CHO + DHA and OB + EE, significant attenuation was observed in mean body mass index and mean thickness of tunica media compared to same in OB. CONCLUSION: Adult obesity has negative impact on body mass index, serum lipid profile and arterial wall structure that persists through aging. Supplementation of choline and DHA or exposure to enriched environment during obesity attenuates these negative impacts through aging.

Hippocampal neural cell degeneration and memory deficit in high-fat diet-induced postnatal obese rats- exploring the comparable benefits of choline and DHA or environmental enrichment.

PURPOSE: Childhood obesity increases risk for neural dysfunctions causing learning and memory deficits. The objective of the study is to identify the effects of high fat diet-induced obesity in postnatal period on serum lipids, memory and neural cell survival in hippocampus and compare the role of choline and DHA or environmental enrichment in attenuating the alterations. MATERIALS AND METHODS: 21 day postnatal male Sprague Dawley rats were assigned as Normal control [NC] fed normal chow diet, Obesity-induced [OB] fed high fat diet, Obesity-induced fed choline & DHA [OB + CHO + DHA], Obesity-induced environmental enrichment [OB + EE] [n = 8/group]. Memory was assessed using radial arm maze. Subsequently blood was collected for serum lipid analysis and rats were euthanized. 5 µm hippocampal sections were processed for cresyl-violet stain. Surviving neural cells were counted using 100 µm scale. RESULTS: Memory errors were significantly higher [p < 0.001, 0.01] in OB compared to same in NC rats. Mean number of surviving neural cells in hippocampus of OB was significantly lesser [p < 0.01] compared to same in NC. Interventions in OB + CHO + DHA and OB + EE significantly attenuated [p < 0.01] memory errors and number of surviving neural cells in hippocampus [CA1, CA3 and DG] compared to same in OB. Moreover, hippocampal neural cell survival was found to be inversely related to serum lipid profile in OB group and was attenuated in OB + CHO + DHA and OB + EE rats. CONCLUSIONS: High fat diet-induced postnatal obesity in rats causes CA1/CA3 hippocampal neuro-degeneration and memory deficits. Supplementation of choline and DHA in obese rats attenuates these deficits.

Supplementation of fenugreek with choline-docosahexaenoic acid attenuates menopause induced memory loss, BDNF and dendritic arborization in ovariectomized rats.

Cognitive impairment due to natural or surgical menopause is always associated with estrogen deficiency leading to reduced brain-derived neurotrophic factor (BDNF). Reduced BDNF levels in menopause affect neuronal maturation, survival, axonal and dendritic arborization and the maintenance of dendritic spine density. Conventional long-term estrogen replacement therapy reported causing the risk of venous thromboembolism and breast cancer. To overcome these undesirable effects, phytoestrogens have been used in menopause-induced condition without the risk of side effects. Therefore, the aim of the present study was to investigate the effect of dietary supplementation of fenugreek seed extract (FG) either alone or in combination with choline-DHA on BDNF and dendritic arborization of pyramidal neurons in CA1 and CA3 regions of the hippocampus in ovariectomized rats. Female Wistar rats of 9-10 months old were divided into six groups as normal control (NC); ovariectomy (OVX); OVX + FG; OVX + choline-DHA; OVX + FG + choline-DHA; and OVX + estradiol. All the groups, except NC, were ovariectomized. After 2 weeks of ovariectomy, dietary supplementation was initiated for a period of 30 days. After supplementation, behavioral studies, BDNF levels and dendritic arborization were estimated. Ovariectomized (OVX) rats showed reduced BDNF levels, dendritic branching points and dendritic intersections of pyramidal neurons in CA1 and CA3 regions of the hippocampus. OVX rats supplemented with FG with choline-DHA showed significantly improved BDNF levels, dendritic branching points and dendritic intersections. These results are demonstrating that FG with choline-DHA supplementation can be an alternative for estrogen replacement therapy to modulate menopause-induced learning and memory deficits.

Rajyoga meditation induces grey matter volume changes in regions that process reward and happiness.

Studies provide evidence that practicing meditation enhances neural plasticity in reward processing areas of brain. No studies till date, provide evidence of such changes in Rajyoga meditation (RM) practitioners. The present study aimed to identify grey matter volume (GMV) changes in reward processing areas of brain and its association with happiness scores in RM practitioners compared to non-meditators. Structural MRI of selected participants matched for age, gender and handedness (n = 40/group) were analyzed using voxel-based morphometric method and Oxford Happiness Questionnaire (OHQ) scores were correlated. Significant increase in OHQ happiness scores were observed in RM practitioners compared to non-meditators. Whereas, a trend towards significance was observed in more experienced RM practitioners, on correlating OHQ scores with hours of meditation experience. Additionally, in RM practitioners, higher GMV were observed in reward processing centers-right superior frontal gyrus, left inferior orbitofrontal cortex (OFC) and bilateral precuneus. Multiple regression analysis showed significant association between OHQ scores of RM practitioners and reward processing regions right superior frontal gyrus, left middle OFC, right insula and left anterior cingulate cortex. Further, with increasing hours of RM practice, a significant positive association was observed in bilateral ventral pallidum. These findings indicate that RM practice enhances GMV in reward processing regions associated with happiness.

Remarkable migration propensity of dental pulp stem cells towards neurodegenerative milieu: An in vitro analysis.

Stem cell therapy provides a ray of hope for treating neurodegenerative diseases (ND). Bone marrow mesenchymal stem cells (BM-MSC) were extensively investigated for their role in neuroregeneration. However, drawbacks like painful bone marrow extraction, less proliferation and poor CNS engraftment following systemic injections of BM-MSC prompt us to search for alternate/appropriate source of MSC for treating ND. In this context, dental pulp stem cells (DPSC) could be an alternative to BM-MSC as it possess both mesenchymal and neural characteristic features due to its origin from ectoderm, ease of isolation, higher proliferation index and better neuroprotection. A study on the migration potential of DPSC compared to BM-MSC in a neurodegenerative condition is warranted. Given the neural crest origin, we hypothesize that DPSC possess better migration towards neurodegenerative milieu as compared to BM-MSC. In this prospect, we investigated the migration potential of DPSC in an in vitro neurodegenerative condition. Towards this, transwell, Matrigel and chorioallantoic membrane (CAM) migration assays were carried-out by seeding hippocampal neurons in the lower chamber and treated with 300 µM kainic acid (KA) for 6 h to induce neurodegeneration. Subsequently, the upper chamber of transwell was loaded with DPSC/BM-MSC and their migration potential was assessed following 24 h of incubation. Our results revealed that the migration potential of DPSC/BM-MSC was comparable in non-degenerative condition. However, following injury the migration potential of DPSC towards the degenerating site was significantly higher as compared to BM-MSC. Furthermore, upon exposure of naïve DPSC/BM-MSCs to culture medium derived from neurodegenerative milieu resulted in significant upregulation of homing factors like SDF-1alpha, CXCR-4, VCAM-1, VLA-4, CD44, MMP-2 suggesting that the superior migration potential of DPSC might be due to prompt expression of homing factors in DPSC compared to BM-MSCs.

Neuroprotection by Human Dental Pulp Mesenchymal Stem Cells: From Billions to Nano.

INTRODUCTION: Mesenchymal Stem Cell (MSC) therapy in recent years has gained significant attention. Though the functional outcomes following MSC therapy for neurodegenerative diseases are convincing, various mechanisms for the functional recovery are being debated. Nevertheless, recent studies convincingly demonstrated that recovery following MSC therapy could be reiterated with MSC secretome per se thereby shifting the dogma from cell therapy to cell "based" therapy. In addition to various functional proteins, stem cell secretome also includes extracellular membrane vesicles like exosomes. Exosomes which are of "Nano" size have attracted significant interest as they can pass through the bloodbrain barrier far easily than macro size cells or growth factors. Exosomes act as a cargo between cells to bring about significant alterations in target cells. As the importance of exosomes is getting unveil, it is imperial to carry out a comprehensive study to evaluate the neuroprotective potential of exosomes as compared to conventional co-culture or total condition medium treatments. OBJECTIVE: Thus, the present study is designed to compare the neuroprotective potential of MSC derived exosomes with MSC-condition medium or neuron-MSC-co-culture system against kainic acid induced excitotoxicity in in vitro condition. The study also aims at comparing the neuroprotective efficacy of exosomes/condition medium/co-culture of two MSC viz., neural crest derived human Dental Pulp Stem Cells (hDPSC) and human Bone-Marrow Mesenchymal Stem Cells (hBM-MSC) to identify the appropriate MSC source for treating neurodegenerative diseases. RESULT: Our results demonstrated that neuroprotective efficacy of MSC-exosomes is as efficient as MSC-condition medium or neuron-MSC co-culture system and treating degenerating hippocampal neurons with all three MSC based approaches could up-regulate host's endogenous growth factor expressions and prevent apoptosis by activating cell survival PI3K-B-cell lymphoma-2 (Bcl-2) pathway. CONCLUSION: Thus, the current study highlights the possibilities of treating neurodegenerative diseases with "Nano" size exosomes as opposed to transplanting billions of stem cells which inherit several disadvantages.

Assessment for learning: a needs analysis study using formative assessment to evaluate the need for curriculum reform in basic sciences.

A needs analysis study for curriculum reform in basic sciences was conducted at Melaka Manipal Medical College, India, by means of a formative assessment method, namely Basic Science Retention Examination (BSRE). Students participated in a BSRE, which comprised recall and clinical multiple-choice questions in six discipline areas. They also rated the clinical relevance of each question and provided responses to three open-text questions about the exam. Pass rates were determined; clinical relevance ratings and performance scores were compared between recall type and clinical questions to test students' level of clinical application of basic science knowledge. Text comments were thematically analyzed to identify recurring themes. Only one-third of students passed the BSRE (32.2%). Students performed better in recall questions compared with clinical questions in anatomy (51.0 vs. 40.2%), pathology (45.1 vs. 38.1%), pharmacology (41.8 vs. 31.7%), and biochemistry (43.5 vs. 26.9%). In physiology, students performed better in clinical questions compared with the recall type (56.2 vs. 45.8%). Students' response to BSRE was positive. The findings imply that transfer of basic science knowledge was poor, and that assessment methods should emphasize clinical application of basic science knowledge.

Modified directed self-learning sessions in physiology with prereading assignments and Pecha Kucha talks: perceptions of students.

The present study reports perceptions of first-year undergraduate medical students ( n = 120), regarding modified directed self-learning (DSL) sessions in physiology. Students were provided with prereading assignments (faculty developed PowerPoint slides containing diagrams with incomplete labeling/flowcharts with missing steps) pertaining to the DSL topic 1 wk before the scheduled small-group DSL presentations. During DSL presentation sessions, which were facilitated by teachers, a few students individually presented learning objectives in the specified topic. Apart from that, students discussed answers for the questions in the prereading assignment. Students were also given an opportunity to use technology to support DSL, by way of involving them in Pecha Kucha (PK) talks. The impact of the modified DSL method was determined by requesting students to respond to a validated questionnaire. Frequency analysis of the responses revealed that >60% of students were positive about the modified DSL sessions improving their DSL, presentation, collaborative learning, and information retrieving skills. Students agreed that PK talks helped them to learn how to organize content (65%), present concise information (65.8%), and apply creativity (72.5%). Even though small in number, there were comments that the prereading assignments were useful for learning. The present study revealed that, even though students actively participated in modified DSL sessions, their perceptions on satisfaction and usefulness of the same toward achievement of various skills were not encouraging. The study generated significant results, which implies that undergraduate medical students should be oriented on the relevance of active learning strategies in their future studies.

Dosage and Passage Dependent Neuroprotective Effects of Exosomes Derived from Rat Bone Marrow Mesenchymal Stem Cells: An In Vitro Analysis.

BACKGROUND: Neurodegenerative diseases comprise a group of disorders for which no treatment is available till date. Stem cell based therapy offers great hope and promise. However, stem cell transplantation is associated with certain disadvantages like poor targeted migration, engraftment and survival of the transplanted cells. MATERIAL & METHOD: Exosomes, a type of extracellular membrane vesicle released by all cell types including stem cells, offer an alternative to stem cell transplantation. Exosome carry a wide array of biomolecules and are implicated in exhibiting substantial benefits in the repair/regeneration of the injured tissue. Thus, exosomes offer an alternative therapeutic approach as a substitute of cell transplantation. In order to utilize exosomes for therapeutic purpose, it is essential to evaluate the appropriate passage number and the dosage to avoid possible cytotoxic effects. Here, we isolated exosomes from different passages of rat bone marrow mesenchymal stem cells (BM-MSC) and analysed the neuroprotective potential of BM-MSC exosomes in an in vitro model of excitotoxicity. RESULT: Our results demonstrated that the exosomes isolated from early passage of rat BM-MSC exhibited more efficient neuroprotective potential as opposed to later passages derived exosomes. Furthermore, the neuroprotective efficacy of exosome is dosage dependent. i.e. the lower dosage of exosomes was found to be neuroprotective, whereas higher dosage of exosomes (from later passages) was found to be detrimental to neurons. The early passage derived exosomes protected neurons through anti-apoptotic, anti-necrotic and anti-oxidant mechanisms. CONCLUSION: Our study suggests that adult stem cells derived exosomes could be a potential therapeutic agent to confer neuroprotection in neurodegenerative diseases like Alzheimer's disease.

Impact of Seasonal Variant Temperatures and Laboratory Room Ambient Temperature on Mortality of Rats with Ischemic Brain Injury.

INTRODUCTION: A popular rat model for hypoperfusion ischemic brain injury is bilateral common carotid artery occlusion (BCCAO). BCCAO surgery when performed in varying geographical locations and during different seasons of the year is reported to have variable mortality rates. Studies have also documented the diminishing influence of Ketamine-Xylazine (KT-XY) on thermoregulatory functions in rodents. AIM: To explore the impact of seasonal variant temperatures and laboratory room ambient temperatures on mortality of rats following BCCAO surgery. MATERIALS AND METHODS: The study has two parts: 1 The first part is an analysis of a three year retrospective data to explore the association between the geographical season (hot summer and cold winter) induced laboratory room ambient temperature variations and the mortality rate in KT-XY anaesthetized BCCAO rats. 2. The second part investigated the effect of conditioned laboratory room ambient temperature (CAT) (23-25(0)C) in KT-XY anaesthetized BCCAO group of rats. Rats were divided into 4 groups(n =8/group) as-Normal control, BCCAO and Sham BCCAO where they were all exposed to unconditioned ambient temperature (UCAT) during their surgery and postoperative care. And finally fourth group rats exposed to CAT during the BCCAO surgery and postoperative care. RESULTS: Pearson's chi-square test indicates a significantly high association (p<0.006) between post-BCCAO mortality and hot season of the year. CAT during the hot season reduced the mortality rate (24% less) in post- BCCAO rats compared to the rats of UCAT. CONCLUSION: Despite seasonal variations in temperature, conditioning the laboratory room ambient temperatures to 23-25(0)C, induces hypothermia in KT-XY anaesthetized ischemic brain injured rodents and improves their survival rate.

Inflammation During Gestation Induced Spatial Memory and Learning Deficits: Attenuated by Physical Exercise in Juvenile Rats.

BACKGROUND: Gestational infections induced inflammation (GIII) is a cause of various postnatal neurological deficits in developing countries. Such intra uterine insults could result in persistent learning-memory disabilities. There are no studies elucidating the efficacy of adolescence exercise on spatial learning- memory abilities of young adult rats pre-exposed to inflammatory insult during fetal life. AIMS AND OBJECTIVES: The present study addresses the efficacy of physical (running) exercise during adolescent period in attenuating spatial memory deficits induced by exposure to GIII in rats. MATERIALS AND METHODS: Pregnant Wistar dams were randomly divided into control and lipopolysaccharide (LPS) groups, injected intra peritoneally (i.p) with saline (0.5ml) or lipopolysaccharide (LPS) (0.5mg/kg) on alternate days from gestation day 14 (GD 14) till delivery. After parturition, pups were divided into 3 groups (n=6/group) a) Sham control and LPS group divided into 2 subgroups- b) LPS and c) LPS exercise group. Running exercise was given only to LPS exercise group during postnatal days (PNDs) 30 to 60 (15min/day). Spatial learning and memory performance was assessed by Morris water maze test (MWM), on postnatal day 61 to 67 in all groups. RESULTS: Young rats pre-exposed to GIII and subjected to running exercise through juvenile period displayed significant decrease in latency to reach escape platform and spent significant duration in target quadrant in MWM test, compared to age matched LPS group. Results of the current study demonstrated that exercise through juvenile/adolescent period effectively mitigates gestational inflammation-induced cognitive deficits in young adult rats. CONCLUSION: Inflammation during gestation impairs offspring's spatial memory and learning abilities. Whereas, early postnatal physical exercise attenuates, to higher extent, cognitive impairment resulted from exposure to LPS induced inflammation during intrauterine growth period.

Infusion of human embryonic kidney cell line conditioned medium reverses kainic acid induced hippocampal damage in mice.

BACKGROUND AIMS: Hippocampal neurodegeneration is one of the hallmarks in neurological and neurodegenerative diseases such as temporal lobe epilepsy and Alzheimer disease. Human embryonic kidney (HEK) cells are a mixed population of cells, including neurons, and their conditioned medium is enriched with erythropoietin (EPO). Because EPO is a known neuroprotectant, we hypothesized that infusion of HEK cells or HEK-conditioned medium (HEK-CM) may provide neuroprotection against kainic acid (KA)-induced hippocampal damage in mice. METHODS: Adult CF1 mice were treated with KA to induce hippocampal damage. On 3rd and 5th days after KA treatment, HEK cells or HEK-CM was infused intravenously through the tail vein. On the 7th and 8th days after KA treatment, all groups of mice were subjected to cognitive and depression assessment by use of a novel object recognition test and a forced swim test, respectively. Subsequent to this assessment, mice were killed and the brain samples were used to assess the histopathology and messenger RNA expression for EPO and B-cell lymphoma-2 (Bcl-2). RESULTS: We found that infusion of HEK cells/HEK-CM improves cognitive function and alleviates symptoms of depression. Histological assessment demonstrates complete neuroprotection against KA-mediated excitotoxicity, and the hippocampal cytoarchitecture of HEK cells/HEK-CM treated mice was comparable to normal control mice. HEK cells/HEK-CM treatment could provide neuroprotection by upregulating the endogenous EPO and Bcl-2 in KA-treated mice. CONCLUSIONS: Our present data demonstrate for the first time that infusion of HEK cells/HEK-CM can prevent excitotoxic hippocampal damage and alleviate consequent behavioral abnormalities.

Dietary docosahexaenoic acid supplementation modulates hippocampal development in the Pemt-/- mouse.

The development of fetal brain is influenced by nutrients such as docosahexaenoic acid (DHA, 22:6) and choline. Phosphatidylethanolamine-N-methyltransferase (PEMT) catalyzes the biosynthesis of phosphatidylcholine from phosphatidylethanolamine enriched in DHA and many humans have functional genetic polymorphisms in the PEMT gene. Previously, it was reported that Pemt(-/-) mice have altered hippocampal development. The present study explores whether abnormal phosphatidylcholine biosynthesis causes altered incorporation of DHA into membranes, thereby influencing brain development, and determines whether supplemental dietary DHA can reverse some of these changes. Pregnant C57BL/6 wild type (WT) and Pemt(-/-) mice were fed a control diet, or a diet supplemented with 3 g/kg of DHA, from gestational day 11 to 17. Brains from embryonic day 17 fetuses derived from Pemt(-/-) dams fed the control diet had 25-50% less phospholipid-DHA as compared with WT (p < 0.05). Also, they had 60% more neural progenitor cell proliferation (p < 0.05), 60% more neuronal apoptosis (p < 0.01), and 30% less calretinin expression (p < 0.05; a marker of neuronal differentiation) in the hippocampus compared with WT. The DHA-supplemented diet increased fetal brain Pemt(-/-) phospholipid-DHA to WT levels, and abrogated the neural progenitor cell proliferation and apoptosis differences. Although this diet did not change proliferation in the WT group, it halved the rate of apoptosis (p < 0.05). In both genotypes, the DHA-supplemented diet increased calretinin expression 2-fold (p < 0.05). These results suggest that the changes in hippocampal development in the Pemt(-/-) mouse could be mediated by altered DHA incorporation into membrane phospholipids, and that maternal dietary DHA can influence fetal brain development.

Enhanced production and dendritic growth of new dentate granule cells in the middle-aged hippocampus following intracerebroventricular FGF-2 infusions.

Declined production and diminished dendritic growth of new dentate granule cells in the middle-aged and aged hippocampus are correlated with diminished concentration of fibroblast growth factor-2 (FGF-2). This study examined whether increased FGF-2 concentration in the milieu boosts both production and dendritic growth of new dentate granule cells in the middle-aged hippocampus. The FGF-2 or vehicle was infused into the posterior lateral ventricle of middle-aged Fischer (F)344 rats for 2 weeks using osmotic minipumps. New cells born during the first 12 days of infusions were labeled via daily intraperitoneal injections of 5'-bromodeoxyuridine (BrdU) and analysed at 10 days after the last BrdU injection. Measurement of BrdU(+) cells revealed a considerably enhanced number of new cells in the subgranular zone (SGZ) and granule cell layer (GCL) of the dentate gyrus (DG) ipsilateral to FGF-2 infusions. Characterization of beta-III tubulin(+) neurons among newly born cells suggested an increased addition of new neurons to the SGZ/GCL ipsilateral to FGF-2 infusions. Quantification of DG neurogenesis at 8 days post-infusions via doublecortin (DCX) immunostaining also revealed the presence of an enhanced DG neurogenesis ipsilateral to FGF-2 infusions. Furthermore, DCX(+) neurons in FGF-2-infused rats exhibited enhanced dendritic growth compared with their counterparts in vehicle-infused rats. Thus, subchronic infusion of FGF-2 is efficacious for stimulating an enhanced DG neurogenesis from neural stem/progenitor cells in the middle-aged hippocampus. As dentate neurogenesis is important for hippocampal-dependent learning and memory and DG long-term potentiation, strategies that maintain increased FGF-2 concentration during ageing may be beneficial for thwarting some of the age-related cognitive impairments.

Strategies for promoting anti-seizure effects of hippocampal fetal cells grafted into the hippocampus of rats exhibiting chronic temporal lobe epilepsy.

Efficacy of hippocampal fetal cell (HFC) grafting for restraining spontaneous recurrent motor seizures (SRMS) in chronic temporal lobe epilepsy (TLE) is unknown. We investigated both survival and anti-seizure effects of 5'-bromodeoxyuridine (BrdU) labeled embryonic day 19 (E19) HFC grafts pretreated with different neurotrophic factors and a caspase inhibitor. Grafts were placed bilaterally into the hippocampi of F344 rats exhibiting kainate (KA) induced chronic TLE, where the frequency of SRMS varied from 3.0 to 3.5 seizures/8-h duration. The first group received standard (untreated) HFC grafts, the second group received HFC grafts pretreated and transplanted with brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and caspase inhibitor Ac-YVAD-cmk (BNC-treated HFC grafts), the third group received HFC grafts pretreated and transplanted with fibroblast growth factor-2 (FGF-2) and caspase inhibitor Ac-YVAD-cmk (FC-treated HFC grafts), and the fourth group served as epilepsy-only controls. Epileptic rats receiving standard HFC grafts exhibited 119% increase in the frequency of SRMS at 2 months post-grafting consistent with 125% increase in seizure frequency observed in epilepsy-only controls during the same period. However, in epileptic rats receiving HFC grafts treated with BNC or FC, the frequency of SRMS was 33-39% less than their pre-transplant scores and 73-76% less than rats receiving standard HFC grafts or epilepsy-only rats. The yield of surviving neurons was equivalent to 30% of injected cells in standard HFC grafts, 57% in HFC grafts treated with BNC and 98% in HFC grafts treated with FC. Thus, standard HFC grafts survive poorly in the chronically epileptic hippocampus and fail to restrain the progression of chronic TLE. In contrast, HFCs treated and grafted with BNC or FC survive robustly in the chronically epileptic hippocampus, considerably reduce the frequency of SRMS and blunt the progression of chronic TLE.

Altered dendritic arborization of amygdala neurons in young adult rats orally intubated with Clitorea ternatea aqueous root extract.

Young adult (60 day old) Wistar rats of either sex were orally intubated with 50 mg/kg body weight and 100 mg/kg body weight of aqueous root extract of Clitoria ternatea (CTR) for 30 days, along with age-matched saline controls. These rats were then subjected to passive avoidance tests and the results from these studies showed a significant increase in passive avoidance learning and retention. Subsequent to the passive avoidance tests, these rats were killed by decapitation. The amygdala was processed for Golgi staining and the stained neurons were traced using a camera lucida and analysed. The results showed a significant increase in dendritic intersections, branching points and dendritic processes arising from the soma of amygdaloid neurons in CTR treated rats especially in the 100 mg/kg group of rats, compared with age-matched saline controls. This improved dendritic arborization of amygdaloid neurons correlates with the increased passive avoidance learning and memory in the CTR treated rats as reported earlier. The results suggest that Clitoria ternatea aqueous root extract enhances memory by increasing the functional growth of neurons of the amygdala.