In our previous studies, we demonstrated that the mutation of His393(6.55) to alanine results in an increased affinity of 1,4-disubstituted phenylpiperazines to the dopamine D(2L) receptor. This change most likely accounts for the reduced steric hindrance in this part of the binding pocket. In this work, we investigated the role of the steric hindrance imposed by the residue His393(6.55) for th...

Purpose: Arylpiperazines have been recognized as the largest and most diverse class of compounds exerting actions on the central nervous system with strong affinity for serotonin and dopamine receptors. We here report the synthesis of some novel arylpiperazines and their evaluation for possible antipsychotic properties. Methods: The target compounds 2-[4-(aryl substituted) piperazin-1-yl]-N-phe...

The interaction of mice submandibular gland cells with LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES), a cationic peptide with immunomodulatory properties, was investigated. LL-37 at a concentration that did not affect the integrity of the cells increased the uptake of calcium and activated a calcium-insensitive phospholipase A(2) (PLA(2)). The small release of ATP induced by LL-37 could not acc...

Vasopressin (VP) transcription in the rat suprachiasmatic nucleus (SCN) in organotypic culture was studied by in situ hybridization histochemistry using an intron-specific VP heteronuclear RNA probe. The circadian peak of VP gene transcription in the SCN in vitro is completely blocked by a 2 h exposure to tetrodotoxin (TTX) in the culture medium, and this TTX inhibition of VP gene transcription...

The serotonin (5-HT)(2A/2c) agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), the 5-HT2C agonist 6-chloro-2-[1-piperazinyl]-pyrazine and the 5-HT2A partial agonist m-chloro-phenylpiperazine (mCPP) were injected bilaterally into the medial prefrontal cortex of male rats. DOI and mCPP, but not 6-chloro-2-[1-piperazinly]-pyrazine, elicited a dose-dependent head-twitch response (HTR). DO...

Ca2+/calmodulin-dependent protein kinase II (CaMKII) plays a critical role in synaptic plasticity and memory formation in a variety of learning systems and species. The present experiments examined the role of CaMKII in the circuitry underlying pavlovian fear conditioning. First, we reveal by immunocytochemical and tract-tracing methods that alphaCaMKII is postsynaptic to auditory thalamic inpu...

Calcium-dependent release of purines was previously demonstrated in cultures of chick retinal cells stimulated with high potassium concentrations but there is no evidence for an exocytotic mechanism of adenosine release from presynaptic terminals. Here we show that activation of NMDA or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate glutamate ionotropic receptors promotes a...

Drug-induced plasticity of excitatory synapses has been proposed to be the cellular mechanism underlying the aberrant learning associated with addiction. Exposure to various drugs of abuse causes both morphological plasticity of dendritic spines and functional plasticity of excitatory synaptic transmission. Chronic activation of μ-opioid receptors (MOR) in cultured hippocampal neurons causes tw...

Pulsed field gradient nuclear magnetic resonance methods combined with nuclear magnetic resonance imaging were used to determine the water diffusion anisotropy in perfused rat hearts at 37°C. It was found that the observed diffusion coefficient DaPP (apparent diffusion coefficient) depends on the orientation of the applied gradient g. When g is parallel to the epicardial surface, the observed d...