Topic: RXFP3

The retrosplenial cortex (RSC) is known for its pivotal role in contextual fear conditioning, receiving inputs from both corticocortical and subcortical pathways, including the nucleus incertus in the pontine tegmentum. This region contains a GABAergic projection rich in relaxin-3 (RLN3), which acts via its Gi/o-protein-coupled receptor, RXFP3. To investigate the involvement of this peptidergic system in contextual fear conditioning, we bilaterally injected adult rat RSC with an adeno-associated virus (AAV) expressing the chimeric RXFP3 agonist R3/I5 or a control AAV and subjected them to cont

The hypothalamic, peptide hormone, oxytocin (OXT), is a powerful modulator of social-, stress- and anxiety-related behaviors, as is the brainstem, neuropeptide relaxin-3 (RLN3). Recent studies indicate the involvement of KCNQ potassium channels in neuronal OXT and RLN3 signaling, with these neuropeptides displaying opposing excitatory and inhibitory actions, respectively. OXT receptors (OXTR) and RLN3 receptors (RXFP3) are expressed by neurons in the rat ventral hippocampal CA3 area (vCA3), which is involved in social behavior and anxiety control; but the possible interaction between OXT and R

Affecting around 10% of world population, chronic pain and its related psychiatric comorbidities are major health issues. Implication of neuropeptides in modulation of pain remains poorly described in the brain. The relaxin-3 (RLN3) neuropeptide displays antidepressant and anxiolytic effects, and our preliminary results indicate an analgesic role in rodents. RLN3 is expressed by nucleus incertus (NI) neurons that project to different cortical (e.g. anterior cingulate cortex (ACC)) and subcortical (e.g. amygdala) areas of pain matrix.We aim at studying the pain modulatory effects of RLN3/RXFP3

The ventral hippocampus (vHPC) is a brain locus centrally involved in the control of stress and anxiety, with dysfunction of its interneuron network strongly implicated in clinical anxiety-related disorders. The vHPC is heavily innervated by neurons in the pontine tegmental, nucleus incertus (NI) – the primary source of the neuropeptide, relaxin-3 (RLN3), in the rat brain. Intriguingly, sustained activation of the RLN3 receptor, RXFP3, in the vHPC of rats increased anxiety and social avoidance [1], yet the precise underlying neuronal mechanisms remain unknown. Therefore, this study investigate

The dentate gyrus of the ventral hippocampus (vDG) is strongly implicated in the pathophysiology of anxiety disorders. vDG is heavily innervated by the nucleus incertus (NI), a dorsal pontine locus highly sensitive to neurogenic stress and the main source of the neuropeptide, relaxin-3 (RLN3) in the rat brain. RLN3 receptor (RXFP3) activation has been shown to modulate behaviours, including stress-related anxiety. However, the effect of RLN3/RXFP3 signaling on vDG neuronal activity has not been examined. Therefore, this study investigated the influence of RLN3 on rat vDG neuronal activity ex v

The interpeduncular nucleus (IPN) is a highly complex and evolutionarily conserved midbrain locus involved in social novelty preference and anxiety control. The IPN is characterised by a high density of the nerve-growth factor (NGF) receptor, TrkA; and notably, social stress strongly promotes brain NGF synthesis. The IPN is densely innervated by the nucleus incertus (NI), a stress-sensitive region that is the primary source of the neuropeptide, relaxin-3 (RLN3). In turn, IPN innervates the ventral hippocampus (vHPC), another key locus for social behaviour and anxiety control. However, the natu

Accurate discrimination between new and familiar stimuli is essential for adaptive responses to an ever-changing environment, and disruptions in this process are strongly related to various neuropsychiatric disorders. Stress is a primary mediator of the development of novelty response-related deficiencies; therefore, we investigated the neuronal mechanisms underlying the possible control of the interpeduncular nucleus (IPN), implicated in signaling novelty preference, by the highly stress-sensitive, brainstem nucleus incertus (NI), the primary central source of the neuropeptide, relaxin-3 (RLN

The oxytocin (OXT) and relaxin-3 (RLN3) signalling systems are involved in shaping social and stress-related behaviours, but the interplay of these neural networks in relevant brain regions including the ventral hippocampus dentate gyrus (vDG), is under explored. The rat vDG is strongly innervated by OXT and RLN3-containing nerve fibres, but possible interactions of these neuropeptide systems in vDG are unknown. Therefore, we investigated the influence of OXT and RLN3 signalling, separately and in combination, on rat and human vDG neurons. Multiplex in situ hybridization (ISH) identified a mod