Hypocretins (also known as orexins) are neuropeptides synthesized in the lateral hypothalamus and perifornical region and projecting widely throughout the brain. They play an important modulatory role in plasticity related to addictive behavior. Hypocretin signaling to the ventral tegmental area (VTA) promotes synaptic plasticity by potentiating glutamatergic inputs to dopamine neurons and is required for the plasticity induced by stimulant drugs like cocaine. Plasticity in the VTA leads to increased output of dopamine neurons and increased release of dopamine in projection areas, which is associated with the development of addiction-related behaviors. Antagonists of hypocretin receptors inhibit some of these behaviors, particularly those with high effort requirements, suggesting a significant role of hypocretin in the motivation to obtain drugs. Furthermore, hypocretin neurons are also targeted by drugs of abuse, such as nicotine. Projections of hypocretin neurons to regions beyond the VTA may also play a significant role in motivation and addiction. Taken together, the hypocretin system may be a prime drug target for treatment of addiction and related disorders.
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http://dx.doi.org/10.1016/B978-0-12-394623-2.00016-0 | DOI Listing |
Adv Drug Deliv Rev
January 2025
Neurodegenerative Diseases Department, Kadimastem Ltd, Pinchas Sapir 7, Weizmann Science Park, Ness-Ziona, Israel; Department of Molecular Genetics, Weizmann Institute of Science, 76100, Rehovot, Israel.
Self-renewal capacity and potential to differentiate into almost any cell type of the human body makes pluripotent stem cells a valuable starting material for manufacturing of clinical grade cell therapies. Neurodegenerative diseases are characterized by gradual loss of structure or function of neurons, often leading to neuronal death. This results in gradual decline of cognitive, motor, and physiological functions due to the degeneration of the central nervous systems.
View Article and Find Full Text PDFBiomater Adv
January 2025
Department of Biomedical Sciences, National Chung Cheng University, Chia-Yi 62102, Taiwan, ROC.
Encapsulated BV6 and SM164, two bivalent second mitochondria-derived activator of caspase (Smac) mimetics, in etoposide (ETO)-lipopolymer nanoparticles (NPs) have been developed to deplete inhibitor of apoptosis proteins (IAP), impair DNA, and produce antagonistic effects on glioblastoma multiforme (GBM) in nude mice. The NPs, composed of cocoa butter (CB) and polyvinyl alcohol (PVA), were stabilized by glycerol monostearate and Pluronic F-127, and grafted with transferrin (Tf) and wheat germ agglutinin (WGA) to dock the blood-brain barrier (BBB) and degenerated dopaminergic neurons. The dual-targeting NPs increased the BBB permeability of BV6, SM164 and ETO via recognizing Tf receptor (TfR) and N-acetylglucosamine that are abundantly expressed on brain microvascular endothelial cells.
View Article and Find Full Text PDFElife
January 2025
Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States.
The mushroom body (MB) is the center for associative learning in insects. In , intersectional split-GAL4 drivers and electron microscopy (EM) connectomes have laid the foundation for precise interrogation of the MB neural circuits. However, investigation of many cell types upstream and downstream of the MB has been hindered due to lack of specific driver lines.
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January 2025
Department of Operative Dentistry and Periodontology, University Hospital Erlangen, Friedrich-Alexander University of Erlangen-Nürnberg, Erlangen, Germany.
Background: Parkinson's disease (PD) is a neurodegenerative disorder characterized by protein aggregates mostly consisting of misfolded alpha-synuclein (αSyn). Progressive degeneration of midbrain dopaminergic neurons (mDANs) and nigrostriatal projections results in severe motor symptoms. While the preferential loss of mDANs has not been fully understood yet, the cell type-specific vulnerability has been linked to a unique intracellular milieu, influenced by dopamine metabolism, high demand for mitochondrial activity, and increased level of oxidative stress (OS).
View Article and Find Full Text PDFMol Psychiatry
January 2025
Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
Age-related dopamine (DA) neuron loss is a primary feature of Parkinson's disease. However, whether similar biological processes occur during healthy aging, but to a lesser degree, remains unclear. We therefore determined whether midbrain DA neurons degenerate during aging in mice and humans.
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