The mechanism of [3H]dopamine [( 3H]DA) release was investigated using primary cultures of dispersed cells from the rat tuberoinfundibular region, which contains tyrosine hydroxylase (TH)-like immunoreactive neurons. The calcium ionophore A23187 at 10 nM and above caused a significant and dose-dependent increase in [3H]DA release. In the presence of 50 microM A23187, [3H]DA release was detectable within 30 s and reached a plateau in 15 min. The induction of [3H]DA release by 50 microM A23187 was abolished by lowering the extracellular calcium concentration with 2 mM EDTA. Maitotoxin, another calcium-channel activator, also increased [3H]DA release at a concentration of 50 ng/ml. Exogenous additions of 100 mIU/ml phospholipase A2 and 10 microM arachidonate caused significant release of [3H]DA. Furthermore, A23187 stimulated [3H]arachidonate release from tuberoinfundibular dopaminergic (TIDA) neurons in a dose- and time-dependent manner. These results suggest that extracellular calcium and arachidonate are involved in the process of [3H]DA release from rat TIDA neurons.

Download full-text PDF

Source
http://dx.doi.org/10.1159/000125267DOI Listing

Publication Analysis

Top Keywords

[3h]da release
20
extracellular calcium
12
release
9
calcium arachidonate
8
release rat
8
rat tuberoinfundibular
8
microm a23187
8
tida neurons
8
[3h]da
6
involvement extracellular
4

Similar Publications

Article Synopsis
  • Parkinson's disease (PD) is rapidly increasing globally, especially in industrialized regions, indicating potential environmental influences, specifically from pollutants like dieldrin, a pesticide.
  • Research on mice reveals that exposure to dieldrin during development makes them more vulnerable to neuron damage and motor function deficits when exposed to α-synuclein, a protein linked to PD.
  • The study shows that while dieldrin exposure increases dopamine release in certain brain areas affected by α-synuclein, it doesn't change VMAT2 activity, suggesting that early exposure to dieldrin may heighten the brain's response to neurodegeneration without obvious signs of damage.
View Article and Find Full Text PDF

Synthetic cathinones, β-keto analogues of amphetamine (or, more correctly, of phenylalkylamines), represent a new and growing class of abused substances. Several such analogues have been demonstrated to act as dopamine (DA) releasing agents. Methylenedioxypyrovalerone (MDPV) was the first synthetic cathinone shown to act as a cocaine-like DA reuptake inhibitor.

View Article and Find Full Text PDF

Here we provide functional and immunocytochemical evidence supporting the presence on Nucleus Accumbens (NAc) dopaminergic terminals of cyclothiazide-sensitive, alfa-amino-3-hydroxy-5-methyl-4-isoxazolone propionate (AMPA) receptors, which activation causes Ca²⁺-dependent [³H]dopamine ([³H]DA) exocytosis. These AMPA receptors cross-talk with co-localized nicotinic receptors (nAChRs), as suggested by the finding that in vitro short-term pre-exposure of synaptosomes to 30 μM nicotine caused a significant reduction of both the 30 μM nicotine and the 100 μM AMPA-evoked [³H]DA overflow. Entrapping pep2-SVKI, a peptide known to compete for the binding of GluA2 subunit to scaffolding proteins involved in AMPA receptor endocytosis, in NAC synaptosomes prevented the nicotine-induced reduction of AMPA-mediated [³H]DA exocytosis, while pep2-SVKE, used as negative control, was inefficacious.

View Article and Find Full Text PDF

Objective: To determine the effects of Angong Niuhuang pill (AGNHW) on lipopolysaccharide (LPS)-induced neuroinflammation and further to investigate the role of realgar and cinnabar on AGNHW-mediated neuroprotection.

Method: Primary rat midbrain neuron-glia cultures were used as an in vitro model to examine the effects of AGNHW on LPS-induced dopamine (DA) neuronal damage. Cultures were divided randomly into five groups: control, LPS, LPS plus AGNHW, LPS plus realgar and LPS plus cinnabar.

View Article and Find Full Text PDF

The AT₁ angiotensin II receptor blockade attenuates the development of amphetamine-induced behavioral sensitization in a two-injection protocol.

Synapse

June 2011

Instituto de Farmacología Experimental Córdoba (IFEC-CONICET), Departamento de Farmacología, Facultad de Ciencias Químicas Universidad Nacional de Córdoba, Argentina.

It has been shown that a single exposure to amphetamine is sufficient to induce long-term behavioral, neurochemical, and neuroendocrine sensitization in rats. Dopaminergic neurotransmission in the nucleus accumbens and the caudate-putamen plays a critical role in the addictive properties of drugs of abuse. Angiotensin (Ang) II receptors are found on the soma and terminals of mesolimbic dopaminergic neurons and it has been shown that Ang II acting through its AT₁ receptors facilitates dopamine release.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!