Objective: Cholinergic system and its neurotransmitter, acetylcholine (ACh), play a major role in both behavior and motor function of the nervous system. Cholinergic neurons synthesize ACh from choline and acetyl-CoA by choline acetyltransferase in the nerve ending. The release of ACh in response to nerve impulses is dependent on the intracellular calcium ([Ca2+]i) concentration and its gradient. The regulation of a synthesis of ACh after depolarization and ACh release is controlled by mass-action effect on choline acetyltransferase equilibrium. Behavioral and motor changes in uremia may be due in part to derangements in ACh metabolism and such possible abnormalities may be related to the state of secondary hyperparathyroidism of chronic renal failure (CRF).
Design: We studied ACh and choline content, choline release, choline kinase activity in brain synaptosomes of CRF with and without secondary hyperparathyroidism and in CRF rats treated with verapamil which normalize [Ca2+]i in brain synaptosomes of CRF rats.
Results: The content of ACh of brain synaptosomes increased progressively with the duration of CRF from 3 to 6 weeks. ACh and choline release as well as choline uptake were significantly higher in CRF rats at all time intervals studied.
Conclusion: Choline content and the activity of choline kinase of brain synaptosomes were deceased after 3 weeks of CRF and were significantly lower than in synaptosomes of normal. Normalization of ACh and choline content as well as ACh release and the activity of choline kinase by parathyroidectomy or treatment with verapamil but these maneuvers did not prevent the rise in choline uptake and choline release. Resting levels of cytosolic calcium of brain synaptosomes in rats with CRF were significantly higher (437 +/- 9 nM) as compared to normal rats (345 +/- 9 nM). This rise in [Ca2+]i was prevented either by parathyroidectomy prior induction of CRF or by treatment of CRF rats with calcium channel blocker verapamil.
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http://dx.doi.org/10.1053/j.jrn.2007.10.025 | DOI Listing |
J Neuroinflammation
January 2025
Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA.
The thrombolytic protease tissue plasminogen activator (tPA) is expressed in the CNS, where it regulates diverse functions including neuronal plasticity, neuroinflammation, and blood-brain-barrier integrity. However, its role in different brain regions such as the substantia nigra (SN) is largely unexplored. In this study, we characterize tPA expression, activity, and localization in the SN using a combination of retrograde tracing and β-galactosidase tPA reporter mice.
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View Article and Find Full Text PDFJ Neurochem
January 2025
CNR Neuroscience Institute, Milano, Vedano al Lambro, Italy.
Mutations in the Transcription Factor 20 (TCF20) have been identified in patients with autism spectrum disorders (ASDs), intellectual disabilities (IDs), and other neurological issues. Recently, a new syndrome called TCF20-associated neurodevelopmental disorders (TAND) has been described, with specific clinical features. While TCF20's role in the neurogenesis of mouse embryos has been reported, little is known about its molecular function in neurons.
View Article and Find Full Text PDFEur J Neurosci
January 2025
CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
In corticostriatal nerve terminals, glutamate release is stimulated by adenosine via A receptors (ARs) and simultaneously inhibited by endocannabinoids via CB receptors (CBRs). We previously identified presynaptic AR-CBR heterotetrameric complexes in corticostriatal nerve terminals. We now explored the possible functional interaction between ARs and CBRs in purified striatal GABAergic nerve terminals (synaptosomes) and compared these findings with those on the release of glutamate.
View Article and Find Full Text PDFNutrients
December 2024
Department of Neurosciences, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, 48940 Leioa, Spain.
: Omega-3 long-chain polyunsaturated fatty acids (PUFAs) support brain cell membrane integrity and help mitigate synaptic plasticity deficits. The endocannabinoid system (ECS) is integral to synaptic plasticity and regulates various brain functions. While PUFAs influence the ECS, the effects of omega-3 on the ECS, cognition, and behavior in a healthy brain remain unclear.
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