Session: 2

PS2-14 | Exploring the contribution of lateral entorhinal cortex to piriform cortex neuronal coding

Olivia Pedroncini


The piriform cortex (PC), the main region of the olfactory cortex, receives afferent sensory inputs from the olfactory bulb (OB) through the lateral olfactory tract (LOT), and extensive inputs from higher-order areas such as the lateral entorhinal cortex (LEC). To understand the contribution of LEC to the processing of odors we study its functional connectivity to excitatory and inhibitory neurons in the PC. We infected LEC with adeno-associated virus expressing channelrhodopsin under CamKIIa promoter to activate excitatory LEC afferents arriving to PC. We recorded then, in acute brain slices, postsynaptic currents and spiking in pyramidal L2/3 neurons and interneurons, in response to photostimulation. We found that excitatory long-range projections coming from LEC evoke different excitation to inhibition balance in each type of neuron. L2 neurons and PV interneurons (PV-IN) receive more excitation than inhibition along a 10Hz stimulation train. We then explored mechanisms of plasticity of olfactory inputs in association with LEC activation and, our preliminary results suggest that association among those inputs results in a potentiated response to LOT afferents. Last, to assess the role of LEC in the processing of odors in vivo, we are conducting experiments to pharmacologically inactivate this region during an odor-visual context associative task and evaluate the effect of LEC inhibition after learning this olfactory behavior.