Role of PrRP in the central nervous system

Informations

Funding country

Hungary

Acronym

-

URL

-

Start date

2/1/2003

End date

12/31/2006

Budget

26,370 EUR

Fundings

Abstract

The prolactin-releasing peptide (PrRP) was introduced few years ago as a new factor in stimulation of prolactin release, but this effect of PrRP turned out to be much weaker than that of the VIP or TRH, known earlier as stimulators of the prolactin release. The role of PrRP as a classic neurotransmitter is controversial because there are a lot of PrRP receptors in the anterior lobe of the pituiarity, but just scattered PrRP immunopozitive fibers can be seen in the median eminence. Synaptic contacts were demonstrated between PrRP immunopozitive fibers and somatostatin, CRH GnRH immunopositive and tuberoinfundibular dopamine synthesising neurons, through which PrRP is able to indirectly modify the hypothalamo-pituitary axis. PrRP has two isoforms called PrRP20 and 31. Its synthesis is under gonadal regulation. There are only three region in the central nervous system, where PrRP synthesising neurons can be observed: in the A1 and A2 cathecolaminergic cell groups, where PrRP colocalises with noradrenaline and in the posteroventral subdivision of the dorsomedial nucleus of the hypothalamus. Recently, PrRP has been demonstrated to influence the energy balance of the organism and it was shown that most of the PrRP expressing neurons posess leptin receptors. In this study, we would like to map morphologically the exact projections of the different PrRP immunopositive cell groups. In other experiments we plan to investigate the effect of the chronic restraint stress on the PrRP mRNA expression as a function of the gonadal status in control and brainstem operated rats. We also would like to investigate the PrRP mRNA expression and its regulation by different hypothalamic and other factors in organotypic slice cultures in vitro.