Search results for "camp"
showing 10 items of 1995 documents
Neurobiology
2016
In the adult mammalian brain, neurogenesis occurs in the dentate gyrus (DG) of the hippocampus throughout the life span. Neurogenesis has been extensively characterized in rodents and to a lesser extent in primates. Within the hippocampus, the adult neurogenic niche is specifically located in the subgranular zone of the DG, where neural stem/progenitor cells (NSPCs) reside. It has been confirmed that these stem cells, which possess astrocytic features, give rise to intermediate progenitors, immature neurons, and neurons. The NSPCs have radial glia-like morphology and electrolucid cytoplasm, in contrast to the immature neurons whose cytoplasm is electrodense, containing abundant polyribosome…
Patterns and rates of nucleotide substitution, insertion and deletion in the endosymbiont of antsBlochmannia floridanus
2009
Genome reduction is a general process that has been studied in numerous symbiotic bacteria associated with insects. We investigated the last stages of genome degradation in Blochmannia floridanus, a mutualistic bacterial endosymbiont of the ant Camponotus floridanus. We determined the tempo (rates of insertion and deletion) and mode (size and number of insertion-deletion events) of the process in the last 200,000 years by analysing a total of 16 intergenic regions in several strains of this endosymbiont from different ant populations. We provide the first calculation of the reduction rate for noncoding DNA in this endosymbiont (2.2 x 10(-8) lost nucleotides/site/year) and compare it with th…
Quinoline anticancer agents active on DNA and DNA-interacting proteins: From classical to emerging therapeutic targets.
2021
Quinoline is one of the most important and versatile nitrogen heterocycles embodied in several biologically active molecules. Within the numerous quinolines developed as antiproliferative agents, this review is focused on compounds interfering with DNA structure or with proteins/enzymes involved in the regulation of double helix functional processes. In this light, a special focus is given to the quinoline compounds, acting with classical/well-known mechanisms of action (DNA intercalators or Topoisomerase inhibitors). In particular, the quinoline drugs amsacrine and camptothecin (CPT) have been studied as key lead compounds for the development of new agents with improved PK and tolerability…
Synergistic cytotoxic interactions between sodium butyrate, MG132 and camptothecin in human retinoblastoma Y79 cells.
2000
This paper studies the effects caused in human retinoblastoma Y79 cells by treatment with combinations of sodium butyrate, the inhibitor of topoisomerase I camptothecin and the inhibitor of 26S proteasome MG132. The combination of sodium butyrate and camptothecin resulted in a strong synergistic cytotoxicity, as revealed by combination indices of 0.77 and 0.52 calculated at IC(50) and IC(75). Synergistic interactions were also demonstrated for combinations of sodium butyrate and MG132, camptothecin and MG132 and for a combination of all three compounds. The cytotoxic effects observed after the combined treatments can be considered a consequence of apoptosis, as suggested by the appearance o…
?-Carboline binding indicates the presence of benzodiazepine receptor subclasses in the bovine central nervous system
1982
Receptor binding studies were performed with tritiated propyl β-carboline-3-carboxylate ([3H]PrCC), tritiated ethyl β-carboline-3-carboxylate ([3H]ECC), and tritiated flunitrazepam ([3H]FNT) in membrane preparations from different regions of the bovine brain and retina. Specific binding in all regions investigated was associated with benzodiazepine receptor sites. However, not all benzodiazepine receptor sites. However, not all benzodiazepine receptors in the regions investigated as determined by the specific binding of tritiated flunitrazepam ([3H]FNT) are available for [3H]PrCC suggesting that specific [3H]PrCC binding labels only one subclass or subpopulation of the benzodiazepine recept…
Glutamatergic activation of hippocampal phospholipase D: postnatal fading and receptor desensitization.
2002
Abstract: Phospholipase D (PLD) activity was determined in rat hippocampal slices between postnatal days 3 and 35. After birth, basal PLD activity was low and, within 2 weeks, increased to reach a plateau that was maintained up to the adult age. Likewise the response to glutamate developed postnatally to reach a maximum at day 8, but then faded rapidly and was almost absent at day 35. Activation of PLD by 4β-phorbol 12β,13α-dibutyrate (PDB) was independent of age, whereas the effect of aluminum fluoride (AlF4−) increased to a plateau within the first week. At day 8, PLD stimulation by glutamate via metabotropic receptors involved protein kinase C activation, but was independent of Ca2+ infl…
Age-related changes in the endocannabinoid system in the mouse hippocampus.
2015
Previous studies have demonstrated that the endocannabinoid system significantly influences the progression of brain ageing, and the hippocampus is one of the brain regions most vulnerable to ageing and neurodegeneration. We have further examined age-related changes in the hippocampal endocannabinoid system by measuring the levels of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in young and old mice from two different mouse strains. We found a decrease in 2-AG but not AEA levels in aged mice. In order to identify the cause for 2-AG level changes, we investigated the levels of several enzymes that contribute to synthesis and degradation of 2-AG in the hippocampus. We found a selective …
Compensatory mechanisms enhance hippocampal acetylcholine release in transgenic mice expressing human acetylcholinesterase
2001
Central cholinergic neurotransmission was studied in learning-impaired transgenic mice expressing human acetylcholinesterase (hAChE-Tg). Total catalytic activity of AChE was approximately twofold higher in synaptosomes from hippocampus, striatum and cortex of hAChE-Tg mice as compared with controls (FVB/N mice). Extracellular acetylcholine (ACh) levels in the hippocampus, monitored by microdialysis in the absence or presence of 10(-8)-10(-3) M neostigmine in the perfusion fluid, were indistinguishable in freely moving control and hAChE-Tg mice. Muscarinic receptor functions were unchanged as indicated by similar effects of scopolamine on ACh release and of carbachol on inositol phosphate fo…
Chelation of synaptic zinc induces overexcitation in the hilar mossy cells of the rat hippocampus.
2004
Complete removal of synaptic zinc by the chelator dietyldithiocarbamate (DEDTC; 500 mg/kg i.p.) in rat was followed by convulsive behaviour including wet dog shakes alternating immobility. Histological analysis 1 day after DEDTC administration detected expression of heat shock protein in the hippocampus restricted to hilar cells. These cells colocalize the marker for neurons and the glutamate receptor GluR2/3 showing that they are excitatory neurons. Additionally, they projected to the contralateral dentate gyrus. Therefore, they correspond to hilar mossy cells. These data show that the synaptic zinc has a role in normal hippocampus avoiding overexcitation, that would impair functionality e…
Immunohistochemical analysis of KCNQ3 potassium channels in mouse brain.
2005
KCNQ-type potassium channels generate the so-called M-current regulating excitability in many neurons. Mutations in KCNQ2/KCNQ3 channels can cause benign familial neonatal convulsions (BFNC). We describe the immunohistochemical staining of adult and developing mouse brain using an antibody directed against the N-terminus of KCNQ3 channels (KCNQ3N). A widespread KCNQ3N immunoreactivity predominantly of neuropil but also of somata was detected in different regions of the adult mouse brain, in particular in the hippocampus, cortex, thalamus and cerebellum. This staining pattern appeared gradually and became more intense during development. In the pyramidal cell layer of the hippocampus, the im…