Neural excitability, synaptic transmission and neuron-glia interactions
Author: Mara Jesús Trujillo | email: jesutruji@gmail.com
María Jesús Trujillo 1°, Fernando Kasanetz 1°
1° IFIBIO Houssay, Facultad de Medicina, UBA-CONICET
Pain is a sensory and emotional experience arising from distributed brain activity. A key brain region for the perception of pain is the anterior insular cortex (AIC), a cortical hub for sensory, emotional, motivational and cognitive functions. Furthermore, the mesolimbic dopaminergic system, which typically responds to motivationally relevant events, modulates pain perception and is compromised during pathological pain. In addition to the effects on other mesolimbic targets, dopamine release in the AIC also affects nociception, with D1 receptors (D1R) exerting an analgesic effect. Despite this, the mechanism by which dopamine affects AIC activity is not clear. Here we combined neuronal tracing, immunohistochemistry and electrophysiology to characterize in detail the dopaminergic system of the AIC. Our preliminary results indicate that D1R -bearing neurons located in superficial layers of the AIC are preferentially inhibitory interneurons, whereas D1R-positive cells from deeper layer comprised both pyramidal cells and interneurons. Then we investigated the effect of D1R stimulation on the activity of dopamine-sensitive cells and on the excitation/inhibition balance of AIC projection neurons. Together, this data will help elucidate how dopamine affects the integration of information in AIC microcircuits. In future experiments, we will address how dopamine modulate AIC responses to noxious stimuli and how this system is affected during pathological pain.