It seems that a deficiency of GABAergic interneurons, found by previous immunohistochemical examinations, does not lead to reduced extracellular GABA levels in the striatum. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.”
“After infection with RML murine scrapie agent, transgenic (tg) mice expressing prion protein (PrP) without its glycophosphatidylinositol (GPI) membrane anchor (GPI(-/)-PrP tg mice) continue to make abundant amounts of the abnormally folded disease-associated PrPres but have a normal life span. In contrast, all age-, sex-, and genetically matched mice with a GPI-anchored PrP become moribund and die due to a chronic progressive CA3 datasheet neurodegenerative
disease by 160 days after RML scrapie agent infection. We report here that infected GPI(-/)-PrP tg mice, although free from progressive neurodegenerative disease of the cerebellum and extrapyramidal and pyramidal systems, nevertheless suffer defects in learning and memory, long-term potentiation, and neuronal excitability. Such dysfunction increases over time and is associated with an increase in gamma aminobutyric acid (GABA) inhibition but not loss of excitatory glutamate/N-methyl-D-aspartic
acid. Enhanced deposition of abnormally folded infectious PrP (PrPsc or PrPres) in the central nervous system (CNS) localizes with GABAA receptors. This occurs with minimal evidence of CNS spongiosis or apoptosis of neurons. The use of monoclonal antibodies reveals an association of PrPres with GABAA
receptors. Thus, the clinical defects of learning and Epigenetics inhibitor memory loss in vivo in GPI(-/)-PrP tg mice infected with scrapie agent may likely involve the GABAergic pathway.”
“We evaluated the effects of intranasal administration of progesterone (PROG) on the activity of dopaminergic neurons in the brain of anesthetized rats by means of microdialysis. Male Wistar rats were implanted with guide cannulae in the basolateral amygdala and neostriatum. Three to 5 days later, they were anesthetized with urethane, and dialysis probes were inserted. After a stabilization period of 2 h, four 30-min samples were collected. Thereafter, the treatment (0.5, 1.0 or 2.0 mg/kg of PROG dissolved in a viscous castor oil mixture, Repotrectinib or vehicle) was applied into the nose in a volume of 10 mu l (5 mu l in each nostril). In other animals, an s.c. injection of PROG (1.0, 2.0 or 4.0 mg/kg) or vehicle was given. Samples of both application ways were collected at 30-min interval for 4 h after the treatment and immediately analyzed with high performance liquid chromatography and electrochemical detection. Intranasal administration of 2 mg/kg of PROG led to an immediate (within 30 min after the treatment) significant increase in the basolateral amygdala dopamine levels.