Neurobiology of maternal behavior. Application of a vector for the pharmacogenetic control of oxytocinergic neurons

Identifier:  TFG:2120

Handle: https://hdl.handle.net/20.500.11797/TFG2120

Authors:  Amiguet Comins, Alejandra

Abstract:
Maternal neurobiology allows to understand maternal behaviour, which is very important for the survival and the neurodevelopment of the offspring. Social behaviour, including the maternal one, is controlled by a circuit known as socio-sexual brain network (SBN) where the nonapeptide oxytocin (OT) is a regulator. The laboratory of Neuroanatomia Funcional is investigating the neuroendocrinology of maternal behaviour in mice considering that rodents are similar to humans. To understand the role of OT in maternal behaviour, we would like to inhibit oxytocinergic (OTergic) cells in vivo using the viral vector AAV2/1-mOXT-hM4D(Gi)-mCherry-WPRE, which induce the expression of DREADD (Designer Receptors Exclusively Activated by Designer Drugs) controlled by OT promoter. The DREADD receptor is sensitive to clozapine-N-oxide (CNO), which administration causes the inhibition of OTergic cells. We would like to analyse the effect of that inhibition on the maternal behaviour. This work aims to perfectionate this farmacogenetic technique before the beginning of the behavioural experiments. We have administrated the vector stereotaxicaly in the preoptic area of female mice. Some injections drove to a high expression of the protein mCherry, which is codified in the vector, in many neurons at the injection place. However, the expression of mCherry is not specific from OT cells at the injection place, so we recommend reducing the viral title until 1010 genome copies/mL (GC/mL). On the other hand, the expression of foreign proteins in mice (hM4D(Gi) and mCherry) could activate the immune system with neuroinflammation and the turn up of the microglial cells in the injection place. Since we have used massive injections of the viral vector, we rejected this possibility by using the microglial marker Iba1 (ionized calcium-binding adapter molecule 1). Here it is shown some proposals to improve the precision in the stereotaxic