Maria Hadjiconstantinou

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In mice administered chronic stress--repeated overnight restraint stress for 7 days--there was a prolonged enhancement of dopamine (DA) uptake into synaptosomes. The mRNA for the DA transporter (DAT) was found to be concomitantly increased in the midbrain, as was the binding of the transporter ligand mazindol to DAT in the nucleus accumbens and(More)
Incubation with either of the protein kinase C activators phorbol 12-myristate 13-acetate (PMA) and sn-1,2 dioctanoylglycerol (DiC8) decreased the uptake of dopamine into striatal synaptosomes, whereas the inactive phorbol ester 4 alpha-PMA had no effect. Washout of PMA and DiC8 failed to reverse the decrease in uptake. Kinetic analysis showed a decrease in(More)
Clozapine is efficacious for treating dopaminergic psychosis in Parkinson's disease and ameliorates l-DOPA-induced motor complications. Based on its pharmacology and reported enhancing effects on dopamine metabolism and tyrosine hydroxylase activity, we investigated whether it could modulate the activity of aromatic l-amino acid decarboxylase (AAAD), the(More)
Nicotine withdrawal causes somatic and negative affective symptoms that contribute to relapse and continued tobacco smoking. So far, the neuronal substrates involved are not fully understood, and an opioid role has been suggested. In this regard, the opioid dynorphin (Dyn) is of interest as it produces aversive states and has been speculated to play a role(More)
Following the administration of a single dose of diisopropylfluorophosphate (DFP) there is a rise of acetylcholine (ACh) in the rat striatum and frontal cortex. With chronic treatment, striatal ACh content returns to normal, but frontal cortex ACh remains elevated. In striatum but not frontal cortex, there is a rise of dopamine (DA) content and turnover(More)
Aromatic L-amino acid decarboxylase (AAAD) is an essential enzyme for the formation of catecholamines, indolamines, and trace amines. Moreover, it is a required enzyme for converting L-DOPA to dopamine when treating patients with Parkinson's disease (PD). There is now substantial evidence that the activity of AAAD in striatum is regulated by activation and(More)
The compound 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a relatively selective neurotoxin that destroys dopamine (DA)-containing nigrostriatal neurons. We have now studied the effects of MPTP on retinal dopaminergic neurons. Acute treatment resulted in the accumulation of DA when evaluated by direct chemical analysis or histofluorescence.(More)
Aromatic L-amino acid decarboxylase (AAAD), an enzyme required for the synthesis of catecholamines, indoleamines, and trace amines, is rapidly activated by cyclic AMP-dependent pathways in striatum and midbrain in vivo, suggesting enzyme phosphorylation. We now report that the catalytic subunit of cyclic AMP-dependent protein kinase (PKA) directly(More)
During pregnancy, the uterus undergoes a profound sympathetic denervation. To explore whether this is associated with changes in neurotrophic factors, we assayed nerve growth factor (NGF) and NGF mRNA in the uterus of non-pregnant and pregnant rats. In the uterine horn, the concentration of NGF and its mRNA decreased during middle and late pregnancy.(More)
We investigated the ability of GM1 to induce phosphorylation of the tyrosine kinase receptor for neurotrophins, Trk, in rat brain, and activation of possible down-stream signaling cascades. GM1 increased phosphorylated Trk (pTrk) in slices of striatum, hippocampus and frontal cortex in a concentration- and time-dependent manner, and enhanced the activity of(More)