alzheimers-disease

Llorente A, Gonzalez De San Roman E, Moreno M, Manuel I, Giralt M, Rodriguez R (2014) Activity mediated by neurolipid (CB1 and LPA1) and neuropeptide (GAL1) receptors in a rat model with cholinergic basal forebrain lesion. Neuroscience 2014 Abstracts 307.25. Society for Neuroscience, Washington, DC.

Summary: The cholinergic basal forebrain neurons (CBFN) which innervate cortical, hippocampal and amygdaloid areas, control learning and memory processes and are damaged in Alzheimer´s disease. An intraparenquimal injection of the 192IgG-saporin (SAP) immunotoxin, specifically eliminates CBFN. The present study examined the activity of endocannabinoid (CB1), lysophosphatidic acid (LPA1), galanin (GAL1) and muscarinic (MR) receptors, measuring Gi/o protein activation by [35S]GTPγS autoradiography in rats after the selective cholinergic basal forebrain lesion. CB1 immunoreactivity (CB1-ir) was also analyzed in the SAP administration area. We observed a high CB1-ir in the basal forebrain of the lesioned rats. The autoradiographic assays revealed that WIN55,212-2 (10 μM) evoked stimulation (CB1 activity) was increased in lateral olfactory tract (data expressed in % stimulation over basal; CSF vs SAP; 55 ± 11% vs 128 ± 13%, p<0.05) and in entorhinal cortex (156 ± 17% vs 277 ± 30%, p<0.01), but decreased in hippocampal dentate gyrus (299 ± 37% vs 166 ± 21%, p<0.05) and in medial amygdala (116 ± 20% vs 50 ± 7%, p<0.05). LPA (10 μM) induced stimulation (LPA1 activity) showed an increase in the internal capsule (60 ± 10% vs 137 ± 19%, p<0.01). The MR activity that was measured using carbachol (100 μM) was increased in hippocampal dentate gyrus (27 ± 6% vs 62 ± 7%, p<0.05) and in entorhinal cortex (55 ± 10% vs 94 ± 11%, p<0.05) but decreased in the nucleus basalis of Meynert (nbM) (46 ± 10% vs 15 ± 6%, p<0.05). Finally, there was an increased stimulation (GAL1 activity) of galanin (1 μM) in the nbM (45 ± 13% vs 80 ± 12%, p<0.05). The CB1-ir and GAL1 activity was increased in the lesioned area where the cholinergic neurotransmission was impaired, indicating a possible neuroprotective action on the surviving CBFN.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Manuel I, Llorente A, Gonzalez de San Roman E, Merino L, Giralt M, Rodriguez-Puertas R (2014) Memory and cholinergic impairment using a new approach of bilateral lesion of rat cholinergic basal forebrain. Neuroscience 2014 Abstracts 134.02. Society for Neuroscience, Washington, DC.

Summary: The cholinergic basal forebrain neurons (CBFN), which innervate cortical, hippocampal and amygdaloid areas control learning and memory processes and are damaged in Alzheimer´s disease (AD). The aim of the present study was to characterize the model of selective induced CBFN death in the nucleus basalis of Meynert (nbM) of adult Sprague-Dawley rats by intraparenquimal injection of the specific CBFN immunotoxin 192IgG-saporin (SAP) (n=11; 1μl/side [135ng/μl]). Learning and memory behavior was evaluated with the passive avoidance (PA) test. The CBFN density and the presence of glial cells were evaluated by immunofluorescence (P75NTR, Neu-N, GFAP, Iba-1). The AChE activity and AChE+ neuron density were analyzed by staining reaction. A significant decrease in CBFN (P75NTR -ir) density was observed in SAP treated rats (-82,7% vs aCSF, p<0,001). We found that cognitive impairment in the PA test and the reduction in the CBFN density in nbM correlated with each other (P75NTR+-ir vs PA, r2=0,51, p<0,05). Similar results were obtained for the reduction in AChE staining in cortical areas (entorhinal cortex: r2=0,55, p<0,01), hippocampus (CA3 pyramidal: r2=0,49, p<0,01) and amygdala (anterior: r2=0,43, p<0,01). Immunofluorescence studies showed a high density of activated microglia (Iba-1-ir) and an abscence of astrocytes (GFAP-ir) in the SAP administration area. Moreover, using MALDI-IMS assay, some lipid species were modified around the lesion area in SAP treated rats. The obtained data on the above described model of CBFN death, mimics the cognitive and cholinergic system impairment described in AD patients.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Hartig W, Saul A, Kacza J, Grosche J, Goldhammer S, Michalski D, Wirths O (2014) Immunolesion-induced loss of cholinergic projection neurones promotes beta-amyloidosis and tau hyperphosphorylation in the hippocampus of triple-transgenic mice. Neuropathol Appl Neurobiol 40(2):106-120. doi: 10.1111/nan.12050

Summary: 3xTg transgenic mice were treated with 2 μg of mu p75-SAP (Cat. #IT-16) into the right lateral ventricle to eliminate cholinergic neurons in the basal forebrain. These mice already have age-dependent β-amyloidosis and tau hyperphosphorylation. This new model supplies a potential framework in which to study the entire pathology of Alzheimer’s disease.

Related Products: mu p75-SAP (Cat. #IT-16)

Laursen B, Mork A, Plath N, Kristiansen U, Frank Bastlund J (2014) Impaired hippocampal acetylcholine release parallels spatial memory deficits in Tg2576 mice subjected to basal forebrain cholinergic degeneration. Brain Res 1543:253-262. doi: 10.1016/j.brainres.2013.10.055

Summary: The Tg2576 mouse strain provides a limited model for Alzheimer’s disease because they do not display degeneration of cholinergic neurons in the basal forebrain – the other main hallmark of Alzheimer’s disease in humans. Using 0.9 μg icv injections of mu p75-SAP (Cat. #IT-16) the authors evaluated mice that had both Aβ deposition and cholinergic depletion. The data show that these mice display cognitive decline and compromised cholinergic levels, creating a viable model for Alzheimer’s disease.

Related Products: mu p75-SAP (Cat. #IT-16)

Burke RM, Norman TA, Haydar TF, Slack BE, Leeman SE, Blusztajn JK, Mellott TJ (2013) BMP9 ameliorates amyloidosis and the cholinergic defect in a mouse model of Alzheimer’s disease. Proc Natl Acad Sci U S A 110(48):19567-19572. doi: 10.1073/pnas.1319297110 PMID: 24218590

Summary: During development bone morphogenetic protein 9 (BMP9) induces the cholinergic phenotype in the basal forebrain. The authors investigated the use of BMP9 as a treatment of basal forebrain cholinergic degeneration, such as is seen in Alzheimer’s disease (AD). Transgenic mice displaying AD phenotypes and expressing GFP in cholinergic neurons received icv infusions of BMP9, and several cholinergic markers were assessed. Anti-p75NTR (Cat. #AB-N01) was used in immunoblotting at a 1:3000 dilution to measure p75 levels. The results demonstrate the protective and therapeutic activity of BMP9 on AD symptoms.

Related Products: NGFr (mu p75) Rabbit Polyclonal (Cat. #AB-N01)

Tiwari D, Warden H, Haynes JM, Nicolazzo JA, Pouton CW, Short JL (2013) Investigating the potential of stem cell based therapy in an immunotoxin mouse model of Alzheimer’s disease. Neuroscience 2013 Abstracts 712.19. Society for Neuroscience, San Diego, CA.

Summary: Purpose: Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by reduced cognitive function. Stem cell based therapeutic approaches are a potential therapeutic option. In order to investigate this possibility the study focuses on the characterization of a dual reporter embryonic stem (ES) cell line and validation of an immunotoxin mouse model of AD for future transplantation experiments. Methods: A dual (mcherry and Lhx8+) reporter ES cell line was derived from the E14Tg2a mouse ES cell line. The ES cells were assessed for their differentiation capability and characterized using mmunocytochemistry. For the immunotoxin model, 6-8 week old C57BL/6 male mice (n = 12) were treated with bilateral intracerebroventricular injections of saline (control) or mu-p75-saporin toxin (0.4µg/µl/mouse) to cause cholinergic neuronal lesions. Mice were cognitively assessed using a novel three day water maze (WM) protocol and the novel object recognition (NOR) paradigm. Immunohistochemistry was done to detect the toxin dependent loss of cholinergic neurons. Results and conclusions: A significant difference in learning the WM task was observed during cued and spatial trials, with toxin-treated mice taking longer to reach the platform than control mice (two way ANOVA; p<0.01). Performance in the WM during the probe trial was also significantly reduced in toxin-treated mice, compared to control mice (t-test; p<0.05), indicating memory loss in toxin-injected mice and better learning in the saline-treated controls. However, no memory impairment was detected using the NOR test. Immunohistochemistry for choline acetyltransferase (ChAT) confirmed a significant loss (p<0.0001; t test) of cholinergic neurons in the medial septum. These data indicate that the toxin model is appropriate for use in subsequent transplantation studies. FACS analysis of the reporter cell line showed the presence of a small population of Lhx8+ cells at day 6 and 10 of differentiation. Immunocytochemistry for ChAT on day 18 cells revealed the presence of a few cholinergic positives neurons as compared to wild type controls. Literature suggests a possible role of Lhx8 in cholinergic development and these cells will be investigated further in order to select cholinergic progenitors for transplantation.

Related Products: mu p75-SAP (Cat. #IT-16)

Nair DV, Al-Badri MM, Rogido M, Pacheco-Quinto J, Peng H, Iacono D, Eckman CB, Eckman EA (2013) Increased hippocampal neurogenesis and prolonged amelioration of memory deficits by chronic oxotremorine treatment in a rodent model of Alzheimer’s disease. Neuroscience 2013 Abstracts 599.01. Society for Neuroscience, San Diego, CA.

Summary: Cholinergic transmission plays a predominant role in memory processes, and loss of basal forebrain cholinergic innervation of the hippocampus has been correlated with memory impairment in Alzheimer’s disease (AD), as well as in decreased hippocampal neurogenesis in rats. Using a rat model of AD-like basal forebrain cholinergic cell loss, our lab has previously shown that central administration of a muscarinic receptor agonist, oxotremorine, for 4 weeks could reverse the spatial working memory deficit triggered by cholinergic denervation and induce hippocampal neurogenesis. The goal of the present study was to examine whether effects of chronic oxotremorine treatment persist beyond the treatment period, possibly indicating a disease-altering effect of the drug, particularly on memory function. Adult female Sprague Dawley rats were injected intracerebroventricularly (icv) with the immunotoxin 192-IgG-saporin (SAP), to induce AD-like basal forebrain cholinergic cell loss. After a 5 week recovery period, the rats then received 8 weeks of icv infusion of either oxotremorine or saline via osmotic minipump. Behavioral testing in a partially baited radial arm maze began 4 weeks after oxotremorine treatment was discontinued. To analyze cell proliferation, rats received intraperitoneal injections of BrdU either during the first 2 weeks of treatment, or at the end of behavioral testing. One month after oxotremorine treatment was discontinued, SAP-lesioned rats showed persistent improvements in radial arm maze acquisition, such that there was no difference in performance among sham/saline, sham/oxotremorine, and SAP/oxotremorine groups. SAP-lesioned rats treated with saline, however, still showed significant impairments compared to the other groups. Neuropathological and stereological analyses of these brains are ongoing, including analysis of hippocampal neurogenesis and neuronal cell counts in both basal forebrain and hippocampal regions. In a parallel cohort of rats analyzed at the end of the 8 week treatment period, initial results indicate no change in cholinergic cell density but a modest increase in the number of GABAergic cells in medial septum/diagonal band of lesioned rats treated with oxotremorine compared to saline. In the dentate gyrus (DG) of the hippocampus, increased numbers of cells labeled with BrdU during the first 2 weeks of treatment persisted to the end of the experiment, with an overall 1.5-fold increase in the number of BrdU labeled cells detected in the DG. These findings demonstrate that muscarinic stimulation is a promising target in the development of drugs to treat disorders involving cholinergic loss, such as AD.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Lee J, Jeong D, Oh J, Lee J, Chang W, Cho Z, Chang J (2013) Selective basal forebrain cholinergic deficits reduce glucose metabolism, cholinergic and GABAergic system in the cingulate cortex. Neuroscience 2013 Abstracts 45.12. Society for Neuroscience, San Diego, CA.

Summary: Reduction of brain glucose metabolism and degeneration of cholinergic basal forebrain neurons are common features in Alzheimer’s disease and have been correlated with memory function. Although regions representing glucose hypometabolism in Alzheimer’s disease patients are target sites of cholinergic basal forebrain neurons, an interaction between cholinergic denervation and glucose hypometabolism is still unclear. To evaluate the changes in glucose metabolism in regions relevant to basal forebrain cholinergic deficits, we damaged basal forebrain cholinergic neurons of rats using 192 IgG-saporin. After 3 weeks, lesioned animals were tested by water maze test or analyzed using 18F-2-fluoro-2-deoxyglucose positron emission tomography. During the probe test in the water maze, performance of the lesion group decreased, considering time spent in both the target quadrant and platform zone. Glucose metabolism in the cingulate cortex of the lesion group decreased compared with the normal group. Additionally, acetylcholinesterase activity and glutamate decarboxylase 65/67 expression both declined in the cingulate cortex. Our results reveal that spatial memory impairment of animals in which basal forebrain cholinergic neurons are selectively damaged is associated with a decline in functions of GABAergic, cholinergic, and glutamatergic systems associated with glucose hypometabolism in the cingulate cortex.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Cutuli D, De Bartolo P, Caporali P, Tartaglione AM, Oddi D, D’Amato FR, Nobili A, D’Amelio M, Petrosini L (2013) Neuroprotective effects of donepezil against cholinergic depletion. Alzheimers Res Ther 5(5):50. doi: 10.1186/alzrt215

Summary: Acetylcholinesterase inhibitors appear to be one of the only pharmacological tools available to reduce cognitive deficits caused by the loss of cholinergic neurons in the basal forebrain. Here the authors pre-treated rats with the aceytlcholinesterase inhibitor donepezil before administering 0.5 μg of 192-IgG-SAP (Cat. #IT-01) into each side of the medial septum. Analysis of working memory, spatial discrimination, social novelty preference, and ultrasonic localizations, along with measuring hippocampal and neocortical caspase-3 activity indicates that donepezil pre-treatment ameliorates some effects of the cholinergic depletion.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Lee YS, Danandeh A, Baratta J, Lin CY, Yu J, Robertson RT (2013) Neurotrophic factors rescue basal forebrain cholinergic neurons and improve performance on a spatial learning test. Exp Neurol 249C:178-186. doi: 10.1016/j.expneurol.2013.08.012

Summary: It is thought that therapeutic treatments of the cholinergic system may be a viable treatment for Alzheimer’s disease. In order to examine this hypothesis the authors administered a total of 160 ng of 192-IgG-SAP (Cat. #IT-01) in the form of bilateral injections into the medial septum. The lesioned animals then received 4-week infusions of nerve growth factor, neurotrophin 3, or both into the lateral ventricles. Animals treated with any neurotrophin, either alone or as a combination, retained more ChAT-positive neurons and performed better on a delayed match-to-position task than control animals. The data strengthen the theory that exogenous neurotrophic factors ameliorate the effects of Alzheimer’s disease.

Related Products: 192-IgG-SAP (Cat. #IT-01)