Neural Circuits and Systems Neuroscience
Author: Olivia Pedroncini Pedroncini | email: olipedroncini@gmail.com
Olivia Pedroncini 1°, Noel Federman 1°, Antonia Marin-Burgin 1°
1° IBioBA CONICET-MPSP
The piriform olfactory cortex (PC), receives afferent sensory inputs from the olfactory bulb and extensive inputs from higher-order areas such as the lateral entorhinal cortex (LEC) -involved in processing of spatial context information.To understand the contribution of LEC to the representation of odors, we study its functional and anatomical connectivity to excitatory and inhibitory neurons in the PC. We recorded in acute brain slices, EPSCs, IPSCs and spiking in pyramidal L2/3 neurons and interneurons, in response to optogenetic activation of LEC excitatory projections. We observed that LEC projections preferentially contact L2 pyramidal neurons and Parvalbumine interneurons (PV). In addition, we found that LEC stimulation evokes different excitation to inhibition balance in each type of neuron. L2 neurons and PV receive more excitation than inhibition along a 10Hz stimulation train compared with L3 pyramidal neurons and Somatostatin interneurons, suggesting a differential routing of inputs within the microcircuit. To assess the role of LEC in the processing of odors in vivo, we conducted experiments to inactivate this region during a GO-NOGO task that involves associations between odors and spatial contexts. We trained transgenic mice expressing the inhibitory receptor hM4di in LEC excitatory neurons and after they reached performance, we injected CNO to silence LEC bilaterally.We observed that both discrimination of contexts and odors were affected under the CNO effect.