Search results for "Neurotransmitter"

Polysialic acid is required for dopamine D2 receptor-mediated plasticity involving inhibitory circuits of the rat medial prefrontal cortex.

2011

Decreased expression of dopamine D2 receptors (D2R), dysfunction of inhibitory neurotransmission and impairments in the structure and connectivity of neurons in the medial prefrontal cortex (mPFC) are involved in the pathogenesis of schizophrenia and major depression, but the relationship between these changes remains unclear. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a plasticity-related molecule, may serve as a link. This molecule is expressed in cortical interneurons and dopamine, via D2R, modulates its expression in parallel to that of proteins related to synapses and inhibitory neurotransmission, suggesting that D2R-targeted antipsychotics/antidepressants…

Characterization of the transporterB0AT3 (Slc6a17) in the rodent central nervous system.

2013

Abstract Background The vesicular B0AT3 transporter (SLC6A17), one of the members of the SLC6 family, is a transporter for neutral amino acids and is exclusively expressed in brain. Here we provide a comprehensive expression profile of B0AT3 in mouse brain using in situ hybridization and immunohistochemistry. Results We confirmed previous expression data from rat brain and used a novel custom made antibody to obtain detailed co-labelling with several cell type specific markers. B0AT3 was highly expressed in both inhibitory and excitatory neurons. The B0AT3 expression was highly overlapping with those of vesicular glutamate transporter 2 (VGLUT2) and vesicular glutamate transporter 1 (VGLUT1…

Neurosteroidogenesis in Rat Retinas

2002

Neurosteroids (steroids synthesized in the CNS) function by modulating neurotransmission. To establish an experimental model for investigation of neurosteroid synthesis and regulation, independent of blood-borne steroids, we examined the steroidogenic activity of isolated rat retinas. We identified progesterone, pregnenolone, dehydroepiandrosterone, desoxycorticosterone, 3 alpha,5 alpha-tetrahydrodesoxycorticosterone, 3 alpha-hydroxy-5 alpha-dihydroprogesterone, 17-hydroxyprogesterone, and 17-hydroxypregnenolone together with their esterified forms. As pregnenolone is the precursor of all steroids, its formation was studied in detail as an index of a steroid-synthesizing tissue. Pregnenolon…

Central Modulatory Neurons Control Fuel Selection in Flight Muscle of Migratory Locust

2003

Insect flight is one of the most intense and energy-demanding physiological activities. High carbohydrate oxidation rates are necessary for take-off, but, to spare the limited carbohydrate reserves, long-distance flyers, such as locusts, soon switch to lipid as the main fuel. We demonstrate that before a flight, locust muscles are metabolically poised for take-off by the release of octopamine from central modulatory dorsal unpaired median (DUM) neurons, which increases the levels of the potent glycolytic activator fructose 2,6-bisphosphate in flight muscle. Because DUM neurons innervating the flight muscles are active during rest but selectively inhibited during flight, they stimulate carbo…

The GABAergic system of the dorsal cortex of lizards: a combined HRP-GABA immunohistochemistry study.

1990

Abstract γ-Aminobutyric acid (GABA)-like immunoreactive (GABA-LI) neurons were found throughout the mediolateral and rostrocaudal axis of the dorsal cortex. They were horizontal, vertical and multipolar cells, mainly distributed in layers 1 and 3. GABA-LI boutons were diffusely distributed in layers 1 and 3, as well as forming basket-like images around layer 2 pyramidal perikarya. Double labelling experiments indicate that GABA-LI cells are an origin of and a target for rostrocaudal intrinsic projections within the dorsal cortex.

Cellular and subcellular distribution of receptors in the entorhinal—hippocampal system: Morphologic and biochemical aspects

1993

Genes, dopamine and cortical signal-to-noise ratio in schizophrenia.

2004

A large body of phenomenological evidence implicates abnormal connectivity of brain macrocircuitry and microcircuitry in schizophrenia. Recent discoveries of susceptibility genes for schizophrenia have zeroed in on the synaptic signaling machinery of cortical microcircuits as fundamental to disease causation and have militated for further revision of the role of dopamine in this illness. Dopamine, long implicated in psychosis and in antipsychotic drug effects, is crucial in optimizing signal-to-noise ratio of local cortical microcircuits. This action of dopamine is achieved principally by D1- and D2-receptor-mediated effects on pyramidal and local circuit neurons, which mediate neuronal exc…

Mammalian glial cells in culture synthesize acetylcholine.

1997

In the present study we demonstrate that acetylcholine is synthesized by cultured mammalian glial cells identified by cell-type specific markers. Primary cultures of rat brain astrocytes or microglia contained 2.0 and 1.6 pmol acetylcholine/10(6) cells on average respectively. Astrocyte cultures established from neonatal mouse brain contained even more acetylcholine (about 80 pmol acetylcholine/10(6) cells). Primary cultures of rat brain astrocytes showed choline acetyltransferase (ChAT) enzyme activity of 3 nmol/mg protein/h; ChAT activity was blocked by 10 microM bromoacetylcholine. In conclusion, these data demonstrate the synthesis of the "neurotransmitter" acetylcholine in cultured gli…

Allosteric modulation of nicotinic acetylcholine receptors as a treatment strategy for Alzheimer's disease

2000

The basic symptoms of Alzheimer's dementia, i.e., a loss in cognitive function, are due to impaired nicotinic cholinergic neurotransmission. To compensate for this impairment by drug treatment, blockers of the acetylcholine-degrading enzyme acetylcholinesterase are applied, even though this approach obviously is prone to many side-effects, including those of muscarinic nature. We have recently described a novel class of nicotinic acetylcholine receptor ligands which, similar to the action of benzodiazepines on GABA(A) receptors, allosterically potentiate submaximal nicotinic responses. The sensitizing effect is a consequence of facilitated channel opening in the presence of allosterically p…

Diurnal variation of corticotropin-releasing factor binding sites in the rat brain and pituitary.

1996

1. Corticotropin-releasing factor (CRF) is thought to be involved in the regulation of the diurnal activity of the hypothalamus-pituitary-adrenal (HPA) axis and to act as a neurotransmitter in the brain. To date it is unknown whether the binding sites of the central CRF system are subject to diurnal variations. 2. We measured the number of CRF binding sites over the course of a complete 24-hr light-dark cycle in the pituitary, amygdala, bed nucleus of the stria terminalis (BNST), cingulate cortex, visceral cortex, paraventricular nucleus of the hypothalamus, hippocampus, and locus ceruleus of rats by in vitro receptor autoradiography with iodinated ovine CRF. A 24-hr time course was also es…