Naslov
Perinatal exposure to 5-hydroxytryptophan reduces barrel size in the somatosensory cortex and increases exploratory behavior in adult rats

Autori
Hranilović, Dubravka ; Blažević, Sofija Ana ; Šoltić Darija ; Jovanov-Milošević, Nataša

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
FENS Regional Meeting : Book of Abstracts / Reglodi, Dora - Pečuh : Hungarian Neuroscience Society, 2017, 193-193

Skup
FENS Regional Meeting 2017

Mjesto i datum
Pečuh, Mađarska, 20.09.2017. - 23.09.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
5HTP ; barrel field ; thalamo-cortical axons

Sažetak
The region in rodent somatosensory cortex called the barrel field (BF) contains distinct features (barrels) consisting of clustered presynaptic thalamocortical axons (TCA) surrounded by postsynaptic layer IV neurons and separated from each other by cell-free areas (septa). The largest barrels with pronounced topographical organization are contained within the posteromedial barrel subfield (PMBSF) and represent the major facial whiskers, which rodents use to actively explore their environment. Growing evidence suggests that serotonin (5-hydroxytryptamine, 5HT) may play an important role in modulation of BF formation. Drugs targeting the 5HT system are widely used in treatments of affective and anxiety disorders. Although selective serotonin reuptake inhibitors represent a common choice of 5HT enhancers during pregnancy, the immediate 5HT precursor, 5-hydroxytryptophan (5HTP), is being increasingly offered as a natural and safer alternative to antidepressant medication. However, consequences of developmental exposure to increased 5HTP concentrations on brain development and behavior have not been studied in animal models or humans. In the present study, we examined the possible influence of perinatal treatment of rats with 5HTP (25mg/kg) on the PMBSF barrels organization, delineation and size. Wistar rats were treated with either 5HTP or saline, from gestational day 13 until birth by subcutaneous injections to pregnant females, and from postnatal day (PND) 1 until PND 21 by receiving subcutaneous injections themselves. Serum 5HT levels were measured by ELISA at the end of treatment. Brain samples were collected from animal sacrificed on PNDs 22 and 70. Cytoarchitecture of the barrel field and barrel size were analyzed after the respective Nissl or cytochrome oxidase staining of tangentially oriented serial sections across the dorsolateral telencephalic wall. The size of the barrels was measured on the scanned slices using NIH ImageJ software. Chronic 5HTP treatment significantly raised serum 5HT concentrations. In both, pups and adults, barrels of 5HTP-treated animals appeared organized and well-defined but were significantly smaller, compared to those in control rats. Since TCA lack 5HT-sinthesyzing machinery, it is possible that excessive extracellular 5HT levels, originating primarily from the increased peripheral 5HT concentrations, prenatally affected TCA branching, while leaving the postnatal TCA pattering and organization of layer IV neurons into barrel walls intact. As adults, these animals displayed significantly increased exploratory activity, which might indicate somatic sensation impairment, possibly as a consequence of the reduced barrel size. Our results obtained on an animal model suggest a need for thorough examination of the potential effect of 5HTP treatment on the developing human brain and its possible neurological/behavioral consequences.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Temeljne medicinske znanosti

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