PhD Scientific Days 2025

Neurosciences

Thalamo-preoptic projection controlling social isolation-induced aggression in rats

Name of the presenter

Láng Tamás

Institute/workplace of the presenter

Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University

Authors

Tamás Láng¹, Botond Drahos¹, Ingrid Csordás¹, Vivien Szendi², Dávid Keller³, Valery Grinevich⁴, Árpád Dobolyi¹

1: Laboratory of Neuromorphology, Department of Anatomy, Histology and Embryology, Semmelweis University
2: Laboratory of Molecular and Systems Neurobiology, Department of Physiology and Neurobiology, Eötvös Loránd University
3: Institute for Systems Physiology, Faculty of Medicine, University of Cologne
4: Department of Neuropeptide Research in Psychiatry, Central Institute of Mental Health, University of Heidelberg

Text of the abstract

Lack of social interaction has been demonstrated to induce aggressive behaviour. In our previous research, we demonstrated that the posterior intralaminar thalamus (PIL) increases positive valence social contacts. The present study aimed to elucidate the role of the PIL-MPOA pathway and the VMH to PIL projection in the induction of aggressive behaviour in male rats subjected to social isolation. To manipulate PIL neurons that are activated by social interaction, we employed the vGATE protocol. This permitted the expression of DREADDs in PIL neurons that had previously been c-Fos activated in response to social interactions. The stimulation of vGATE-tagged PIL neurons reduced aggressive behaviour, whereas the inhibition of these neurons was found to increase aggression. The use of c-Fos immunolabeling revealed that stimulation of vGATE-labeled PIL neurons activated the MPOA neurons. In turn, the inhibition of PIL reduced c-Fos expression during aggression in the MPOA. To investigate the PIL-MPOA pathway, viruses expressing DREADDs were injected into the PIL and intracerebral cannulas were implanted above the MPOA. This allowed us the selectively manipulate the terminal fibers originating from the PIL in the MPOA region through local CNO administration. Stimulation of this neural pathway also reduced aggression, while its inhibition increased it. In addition, the role of VMH-PIL projections in aggressive behavior was investigated, and it was found that the activation of this pathway increased aggressive behaviour. We found that neurons in the MPOA reached by the PIL express oxytocin receptors (OTR). We inhibited the MPOA OTR neurons and observed an increase in aggression. In conclusion, the activation of PIL neurons leads to the inhibition of aggressive behaviour through their projections to MPOA. This may contribute to the prevention of aggressive behavior through social interaction. Meanwhile, the projections of VMH neurons may counteract this prosocial effects.

Funding: EKÖP-24-3-II;EFOP-3.6.3 VEKOP-16-2017-00009, MTA National Brain Research Program 3.0 , NKFIH OTKA K146077, OTKA National Research Excellence program 151425, Semmelweis Excellence Program and SE 250+ 24/25/I, SE 250+ 24/25/II