Volume 12, Issue 3, September 2010

Editoral in Hungarian

Ildikó Miklya

Abstract
Amikor az a megtiszteltetés ért, hogy a Neuropsychopharmacologia Hungarica szerkesztőbizottságának tagjává választottak, és az ilyenkor szokásos beköszöntő levél tartalmán gondolkodtam, eszembe jutott, milyen hatást gyakorolt rám Ban, Healy, és Shorter ’The Rise of Psychopharmacology’ című kötete. Ez a jubileumi kiadvány, melyet a Collegium Internationale Neuropsychopharmacologicum (CINP) megszületésének 50. évfordulójára megemlékezésként adtak ki, ragyogó összefoglalása annak a forradalomnak, mely az 1950-es években kezdődött el, majd teljesedett ki a neuropszichofarmakológia lélegzetelállító fejlődése eredményeként. Olyan új hatásmódú vegyületcsaládokat dolgoztak ki gyors egymásutánban, melyek lehetővé tették a pszichés működéseket alapvetően befolyásoló élettani mechanizmusok molekuláris alapjainak megismerését. Az új ismeretek lehetővé tették az elmebetegségek eladdig elképzelhetetlen hatékonyságú gyógyszeres befolyásolását. 
     És most egy újabb forradalom kezdődik el. A 21. század a nanovilág feltárásának, széleskörű megismerésének és a nanotechnológiának az évszázada lesz – vallják sokan. Ez a küszöbön álló nanoforradalom igazából a természet ajándéka, hiszen a 4 milliárd éves földi élet a kezdetektől úgy fejlődött, hogy az élő szervezetek az atto/femto/piko/nano molekuláris szinten építkezve fejlesztették ki legfontosabb élettani mechanizmusaikat, melyek molekuláris szintű megvalósítását most kezdi a tudomány feltárni. Ez a technológia, a természet e „lego játéka” eredményezi az élő világ végtelen variációját. Szerencsére a tudomány és a technika eljutott arra a fejlettségi szintre, hogy a 10-9 méteres nanotartományban is tud már célzottan építkezni.
     A nanomedicina területére szorítkozva a nanotechnológia minőségi ugrást jelenthet a meglévő gyógyszerek hatékonyabbá tételében és mellékhatásaik csökkentésében azáltal, hogy irányíthatóvá válnak a molekulák és csak az optimális hatás jön létre. A multifunkcionális nanogyógyszer célba juttató komponense például biztosítja, hogy a hatóanyag a specifikus molekuláris kampó segítségével csak a beteg sejthez kötődjön. Vagy az emberiség gyógyszerkincse kibővülhet olyan új anyagokkal, amelyek hatékonysága már a nanoskálán is kimutatható, és elhagyhatjuk a milligrammos, mikrogrammos mérettartományokat, ami új elméletek megszületésére és a prevenciós terápia kialakulására ad végtelen lehetőséget.
     Jó példa erre a Knoll nevéhez fűződő agytörzsi enhancer reguláció felfedezése, melyet a deprenil és  a BPAP kidolgozása tett lehetővé. Az agytörzsi enhancer reguláció olyan enhancerérzékeny neuronok létén alapul, melyek ingerlékenységüket endogén, vagy szintetikus enhancer vegyületek (pl.: PEA, triptamin, illetve ezek szintetikus analógjai, (-)-deprenil, (-)-BPAP) hatására a másodperc tört része alatt már femto-pikomolekuláris koncentrációban fokozni képesek. Éppen ezért ígéretes preventív célú alkalmazásuk. Mivel az enhancer hatás pontos mechanizmusa még nem ismert, a nanomedicina új megközelítési technikáinak figyelembevételével a liposzómába zárt igen kis mennyiségű hatóanyaghoz kapcsolt jeladó biztosíthatná az eddig ismeretlen folyamat nyomon követését, meghatározását. 
     A nanoterápia ma még csak a tumoros és gombás megbetegedések esetében alkalmaz nanokapszulákat, de a nanomedicina minden bizonnyal egyre nagyobb szerepet kap az orvostudomány többi területén is, nem hagyva ki a pszichiátriát, neurológiát és geriátriát sem, új reményeket keltve a pszichiátriai és a neurodegeneratív betegségek, valamint az öregedés kezelésében. 
Abstract

Nanotechnology, the great promise of the 21st century, may revolutionize also the art
of healing. Previously unexpected broadening of diagnostic procedures and methods
to deliver specific drugs acting in lower than nanomolecular concentrations right to the
target cells may play a crucial role in the rapid development of preventive medicine.
In this context, (-)-deprenyl/selegiline, a drug developed 40 years ago and still worldwide used to treat Parkinson’s disease, Alzheimer’s disease and depression, by enhancing
the activity of catecholaminergic neurons in the brain stem via a previously unknown
mechanism [catecholaminergic activity enhancer (CAE) effect], is a highly promising
experimental tool for further research in this direction. The same fits for (-)-BPAP, the
newly developed enhancer substance, 100 times more potent than (-)-deprenyl, which in
contrast to the latter is not only an enhancer of the catecholaminergic neurons but also
of the serotonergic neurons in the brain stem. Tiny amounts of enhancer substances are
closed in liposomes and marked with a specific signal to help identify the exact location
of the target cells, through the activation of which the drug exerts its specific enhancer
effect. The method also offers an approach to better understand the up-to-the-present
unknown mechanism of the enhancer effect.

Keywords: enhancer substances, enhancer regulation, (-)-deprenyl/selegiline,
(-)-BPAP, nanotherapy

Abstract

The dopamine system plays a crucial role in the pathophysiology of many neuropsychiatric
disorders. Altough there is sufficient information and knowledge about several dopamine
receptor subtypes and their functions, until the last decade the role of the D3
receptor was
almost unclear. Recent research data proved that the D3
receptor might have a significant
role in fine tuning the modulation of dopaminergic neurotransmission. Cariprazine is a
novel agent developed in Hungary, its activity on the dopamine D3
receptor might open
up new dimensions in the pharmacotherapy of schizophrenia and affective disorders.

Keywords: dopamine system, dopamine, D3 receptor, cariprazine

Abstract

“Ecstasy”, 3,4-methylenedioxymethamphetamine (MDMA), an amphetamine analogue is one of the most widely used recreational drugs. In spite of the fact that neurotoxic effects of MDMA has been found in several species from rodents to non-human primates, and results increasingly point to damage also in human MDMA users, data about the sensitivity of different brain areas and the recovery after neuronal damage are scarce. Serotonin transporter (5-HTT) mRNA in the raphe nuclei also has not been examined. Humans with genetic predisposition for the slow metabolism of MDMA, the so-called “poor metabolizers” of debrisoquin are at higher risk. Five- 9% of the Caucasian population is considered to carry this phenotype. These studies were carried out in Dark Agouti rats, a special strain that show decreased microsomal CYP2D1 isoenzyme activity, and thus may serve as a model of vulnerable human users. These works were designed to characterize MDMA-induced damage and recovery of the serotonergic system including sleep and morphological changes within 180 days. In our experiments we investigated the 5-HTT mRNA expression in the brainstem and medullary raphe nuclei, 5-HTT immunoreactive (IR) fibre densities in several brain areas, and 16 functional measures of sleep in response to a single dose of +/- MDMA (15mgkg). Furthermore, behavioural experiments were performed 21 days after MDMA treatment. We found similar changes in 5-HTT mRNA expression in the examined raphe nuclei, namely transient increases 7 days after MDMA treatment followed by transient decreases at 21 days. Significant (20–40%), widespread reductions in 5-HTT-IR fibre density were detected in most brain areas at 7 and 21 days after MDMA administration. All cortical, but only some brainstem areas were damaged. Parallel to the neuronal damage we observed significant reductions in rapid eye movement (REM) sleep latency, increased fragmentation of sleep and increases in delta power spectra in non-REM sleep. At 180 days almost all functional changes in sleep were normalized together with 5-HTT mRNA expression in the examined raphe nuclei and the recovery of 5-HTT-IR fibre density in most brain areas. Our results also suggest that the acute MDMA administration abolished aggressive behaviour but MDMA pretreatment and the consequent depletion of serotonergic terminals did not affect aggression. Our findings concerning the changes detected in 5-HTT mRNA expression and fibre density indicate lasting impairment of the serotonergic system and suggest that a single use of MDMA may be associated with long-lasting cognitive, learning, memory and mood deficits and sleep disturbances particularly when a constellation of genetic vulnerability and certain environmental factors are present. Our data provide further evidence for the connection between altered serotonergic functions and sleep disturbance.

Keywords: MDMA, serotonin transporter, raphe nucleus, REM latency, aggression

9-hydroxy-risperidone (9OHRIS) prevents stress-induced ß-actin overexpression in rat hippocampus

Sára Kálmán, Magdolna Pákáski, Szabina Szűcs, János ifj. Kálmán , Örsike Fazekas, Petra Sántha, Gyula Szabó, Zoltán Janka and János Kálmán

Abstract

Alzheimer’s disease (AD) is the most frequent form of neurodegenerative dementias.
The aetiology and the exact pathomechanism of AD is not known, but stress has been
considered recently in the aetiology. Beside the abnormal metabolism of the amyloid
– precursor protein (APP), the hyperactivity of the mitogen – activated protein kinase 1
(MAPK1) involved in the hyperphosphorylation of the tau proteins – which are considered
as the major component of neurofibrillary tangles –, in addition to ß-actin, being involved
in synaptogenesis and neuronal plasticity, are all considered as important contributors of
the development of AD specific neuropathological changes. The major aim of our present
investigation was to examine the effect of stress on the expression of APP, MAPK1 and
ß-actin mRNAs in the rat hippocampus and cortex. The effect of 9-hydroxy-risperidone
(9OHRIS) on the transcription of these genes was also examined. Adult, male Wistar rats
were exposed to chronic immobilization stress for 3 weeks. The 9OHRIS (4 mg/bwkg)
was administred by gastric tube. Four groups were formed depending on the treatment:
(1) control, (2) stress, (3) 9OHRIS, (4) stress and parallel 9OHRIS treatment (n=5-6). The
expression of APP, MAPK1, ß-actin mRNAs from the perfused brain samples was measured
with real-time PCR technique. The ß-actin mRNA was significantly overexpressed in the
hippocampus after 3 weeks of stress treatment. On the other hand, the stress induced
hippocampal ß-actin mRNA overexpression was repressed by the 9OHRIS treatment.
There were no changes in the cortical or hippocampal expression of APP and MAPK1
mRNAs after neither the stress nor the 9OHRIS treatments. These results emphasize
the importance of the stress induced ß-actin expression in rat hippocampus. The stress
induced alterations in the ß-actin RNA expression could be associated with neuronal
plasticity and adaptional processes, which could be modified by the 9OHRIS treatment.
Our findings indicate that a second generation antipsychotic drug could have a beneficial
effect in the pathomechanism of stress and this may have relevance in the treatment of
such devastating conditions like AD and psychotic disorders.

Keywords: Alzheimer’s disease, stress, hippocampus, amyloid-precursor protein,
mitogen-activated protein kinase, ß-actin, 9-hydroxy-risperidone, real-time PCR

Abstract

MR spectroscopy (MRS) is a widely used and useful additional tool in the diagnostic
process of several neuropsychiatric disorders. Despite several MRS studies in bipolar
spectrum reserach, establishing a clean image about special metabolite alterations in
the disorder still needs further investigation. The first part of this case study presents a
bipolar II patient and her first 3T MR spectroscopy in drug-naive conditions, comparing
to a healthy subject. Having finished the first MRS investigation, we applied lamotrigine
medication. The ongoing second part of the study will show the data of the second MRS
scan, after 5 month of lamotrigine therapy.

Kewyords: MR spectroscopy, bipolar disorder, N-Acetyl-Aspartate, cholin, creatin