Search results for "dopaminergic"

Dopaminergic modulation of evoked vasopressin release from the isolated neurohypophysis of the rat

1982

1. Neurointermediate lobes of rat pituitaries were incubated in Locke or Krebs solution, and the vasopressin released into the medium was assayed on the blood pressure of the pithed rat or by a radioimmunological procedure. Release of vasopressin over resting levels was evoked either by incubation with 60 mM KCl (high K) solution or by electrical stimulation of the pituitary stalk. Two different kinds of electrical stimulation were carried out. Procedure A (1 ms, 10 Hz, 5 times for 1 min within 10 min) induced a vasopressin overflow which was greatly calcium-dependent but only insignificantly sensitive to tetrodotoxin (TTX). Procedure B (0.2 ms, 15 Hz, 10 s trains with 10 s intervals for 10…

Acute oral administration of low doses of methylphenidate targets calretinin neurons in the rat septal area.

2015

Methylphenidate (MPD) is a commonly administered drug to treat children suffering from attention deficit hyperactivity disorder (ADHD). Alterations in septal driven hippocampal theta rhythm may underlie attention deficits observed in these patients. Amongst others, the septo-hippocampal connections have long been acknowledged to be important in preserving hippocampal function. Thus, we wanted to ascertain if methylphenidate administration, which improves attention in patients, could affect septal areas connecting with hippocampus. We used low and orally administered methylphenidate doses (1.3; 2.7 and 5mg/Kg) to rats what mimics the dosage range in humans. In our model, we observed no effec…

Characterisation of [11C]PR04.MZ in Papio anubis baboon: A selective high-affinity radioligand for quantitative imaging of the dopamine transporter

2012

N-(4-fluorobut-2-yn-1-yl)-2β-carbomethoxy-3β-(4′-tolyl)nortropane (PR04.MZ, 1) is a PET radioligand for the non-invasive exploration of the function of the cerebral dopamine transporter (DAT). A reliable automated process for routine production of the carbon-11 labelled analogue [11C]PR04.MZ ([11C]-1) has been developed using GMP compliant equipment. An adult female Papio anubis baboon was studied using a test–retest protocol with [11C]-1 in order to assess test–retest reliability, metabolism and CNS distribution profile of the tracer in non-human primates. Blood sampling was performed throughout the studies for determination of the free fraction in plasma (fP), plasma input functions and m…

Dopamine agonists in schizophrenia: a review.

1995

Although it is unlikely that the different types of course and severity of schizophrenia are caused by one neurochemical abnormality alone, indirect pharmacological evidence still suggests a relative excess of dopaminergic activity being implicated in the pathogenesis of most of the schizophrenic symptoms, e.g. positive symptomatology. Synthesis and release of dopamine as well as firing rates of dopaminergic neurons are controlled by stimulation of autoreceptors via a negative feedback regulation. Investigations on therapeutic effects of autoreceptor-nonselective dopamine agonists in schizophrenia have yielded inconsistent results. Dopamine autoreceptor agonists like pramipexole, roxindole,…

Psychotropic Effect of Combined Estrogen-Vit B6 Treatment in Endogenously Depressed Females

1985

Estrogens are among the most commonly prescribed substances in females. Also endogenous estrogen levels change dramatically throughout life and this biological variable has been associated with several psychological signs like premenstrual tension syndrome and depression in older age. Along with clinical practice there is increasing evidence from neuropharmacology suggesting a psychotropic action of estrogens (review: Holsboer, 1982). The most prominent findings are: 1. Reduction of monoamine-oxidase (MAO)-activity by estrogens (McEwen et al., 1978); 2. Competitive inhibition of catechol-o-methyltransferase by 2-hydroxyestrogens, which are major metabolites of estrogens in the CNS (Breuer e…

Molecular modelling studies on dopamine-amino acid conjugates as potential dopaminergic modulators

2015

Preferential Modulation of the GABAergic vs. Dopaminergic Function in the Substantia Nigra by 5-HT2C Receptor

2009

Serotonin (5-HT) is intimately involved in the modulation of the basal ganglia circuitry and in its pathologies. The 5-HT pivotal role is supported by anatomical evidence demonstrating a large serotonergic innervation throughout the basal ganglia, with the highest concentration of this indole in the substantia nigra (SN). Among all the 5-HT receptors present in the SN, the 5-HT2C receptor subtype seems to be one of the principal receptors through which 5-HT exerts its function. In this chapter, we present in vivo electrophysiology and microdialysis evidence showing that the selective activation of 5-HT2C receptors does not affect dopaminergic function whereas it has a profound impact on GAB…

Il trattamento con RSV e l’espressione transgenica di PGC-1α proteggono i neuroni dopaminergici nel modello MPTP murino del morbo di Parkinson. Resve…

2012

Electrophysiological and neurochemical characterization of 7-nitroindazole and molsidomine acute and sub-chronic administration effects in the dopami…

2009

Nicotine, the main psychoactive ingredient in tobacco, stimulates dopamine (DA) function, increasing DA neuronal activity and DA release. DA is involved in both motor control and in the rewarding and reinforcing effects of nicotine; however, the complete understanding of its molecular mechanisms is yet to be attained. Substantial evidence indicates that the reinforcing properties of drugs of abuse, including nicotine, can be affected by the nitric oxide (NO) system, which may act by modulating central dopaminergic function. In this study, using single cell recordings in vivo coupled with microiontophoresis and microdialysis in freely moving animals, the role of NO signaling on the hyperacti…

POSTNATAL DEVELOPMENTAL CHANGES IN ENTERIC DOPAMINERGIC SYSTEM

2013

The postnatal period is a key period of life, characterized by the maturation of various organs and in particular of the gut. Currently, we have a poor understanding of the development of neurological and endocrine factors that control intestinal motility. Such knowledge can provide indications about the potency, efficacy, or therapeutic range of a drug in premature infants. Dopaminegic antagonists are often used as prokinetic drugs to treat impaired GI propulsion, although the role of the enteric dopaminergic system in the control of intestinal motility in neonatal vs adult has not been adequately addressed. In this view the aim of this study, was to examine, the functionality of the dopam…