Utjecaj perinatalnog izlaganja povišenim koncentracijama serotonina na histološku građu somatosenzoričke kore odraslih štakora

master's thesis

• Title (english): The effect of perinatal exposure to increased serotonin concentrations on histological structure of somatosensory cortex of adult rats
• Author: Darija Šoltić
• Mentor: Dubravka Hranilović (mentor)
• Mentor: Nataša Jovanov Milošević (mentor)
• Committee member: Dubravka Hranilović (predsjednik povjerenstva)
• Committee member: Gordana Lacković-Venturin (član povjerenstva)
• Committee member: Mirta Tkalec (član povjerenstva)
• Committee member: Ana Galov (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2016-02-24, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Serotonin (5HT) je biološki aktivan amin prisutan u mozgu i perifernim tkivima sisavaca gdje izvršava različite funkcije, ovisno o odjeljku u kojem se nalazi. U mozgu regulira razvoj serotonergičnih neurona i ciljanih tkiva tijekom neurogeneze, dok u razvijenom mozgu preuzima ulogu neurotransmitera. Cilj ovog diplomskog rada bio je ispitati utjecaj perinatalno inducirane povišene razine serotonina, primjenom neposrednog prekursora sinteze serotonina, 5-hidroksitriptofana (5HTP, 25 mg/kg), ili inhibitora razgradnje serotonina, tranilcipromina (TCP, 2mg/kg) na razvoj bačvastog polja u somatosenzoričkoj kori mozga štakora. Mozgovi su prethodno izdvojeni neposredno po završetku tretmana (PND 21) ili u odrasloj dobi (PND 70). Tangencijalne rezove somatosenzoričke kore podvrgnula sam histološkoj metodi bojanja po Nisslu, te histokemijskoj metodi bojanja citokrom oksidazom (CO). Kvalitativna analiza bačvastog polja vršena je pregledavanjem rezova Nissla pod mikroskopom. Bačvasta polja na rezovima bojanim CO pronašli smo pod mikroskopom i fotografirali. Programom ImageJ ocrtali smo bačve unutar bačvastog polja, te izmjerili površinu koja je služila za kvantitativnu usporedbu eksperimentalnih skupina s kontrolnom, tretiranom fiziološkom otopinom. Povišene razine serotonina imale su značajan učinak na bačvasto polje mladunaca, pri čemu je tretman 5HTP-om rezultirao manjom površinom bačvastog polja i pojedinačnih bačvi, dok je je TCP narušio strukturu bačvi. Učinci tretmana 5HTP-om, vidljivi i u mozgu odraslih životinja, ukazuju na smanjeno grananje talamokortikalnih neurona tijekom prenatalnog dijela tretmana. Učinci TCP-a nisu zadržani u odraslih životinja, pa pretpostavljamo da je došlo do odgođenog sazrijevanja bačvastog polja uslijed kronične izloženosti povišenim koncentracijama serotonina u postnatalnom dijelu tretmana.

Abstract (english)

Serotonin (5HT) is biologically active amine present in the brain and peripheral tissues of mammals where it has various functions, depending on the compartment. In the brain, during neurogenesis, it regulates the development of serotonergic neurons and target tissues, while later it assumes the function of a neurotransmitter. The aim of this graduation thesis was to examine the effect of perinatally induced high serotonin levels on the development of barrel field in the rat somatosensory cortex, induced by treatment with the immediate serotonin precursor ,5-hydroxytryptophan (5HTP, 25 mg/kg), and inhibitor of serotonin degradation, tranylcypromine (TCP, 2 mg/kg). Brains were collected on PND 21 or PND 70. Tangential sections of somatosensory cortex where used for histological processing with Nissl staining method, and histochemical method for cytochrome oxidase staining (CO). Qualitative analysis of barrel field were conducted by examination of Nissl sections under the microscope. We found barrel field on CO sections under the microscope and photographed them. In software ImageJ we draw barrels in barrel field, measured their area surface and conducted analysis of quantitative differences between treated and control group. High serotonin levels had significant effect on barrel field of the pups, with 5HTP treatment resulting in smaller barrel field and barrel area, and TCP treatment disrupting their structure. Treatment effects of 5HTP, still visible in adult rats, point to the decreased branching of thalamo-cortical axons during the prenatal phase of the treatment. Since the effects of TCP were not present in the brains of adult animals, we assume that the cronic exposure to high serotonin levels in the postnatal phase of the treatmen only delayed maturation of the barrel field.

• Keywords: bačvasto polje; bačve; tranilcipromin; 5-hidroksitriptofan
• Keywords (english): barrel field; barrels; 5-hydroxitryptophan; tranylcypromine
• Language: croatian
• URN:NBN: urn:nbn:hr:217:891405
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-05-12 11:23:14