Modulation of neuronal responses in the olfactory cortex by basolateral amygdala and cholinergic inputs

ROMANO, SEBASTIAN ALEJO; FEDERMAN, NOEL; MARIN-BURGIN, ANTONIA

Buenos Aires

Conferencia; 2nd Federation of Latin American and Caribbean Neuroscience Societies (FALAN) Conference; 2016

FALAN

A unique feature of olfaction is that olfactory processing is highly dependent on past experience and context. The piriform cortex (PC), the largest subregion of the olfactory cortex, receives afferent (bottom-up) olfactory inputs from the olfactory bulb through the lateral olfactory tract (LOT), and extensive associative (top-down) inputs from associational fibers (ASSN). Some of these top-down projections arise from components of the limbic system that are heavily implicated in emotion and memory, like the basolateral amygdala (BLA). Moreover, diverse neuromodulatory nuclei innervate the PC. Here, we present preliminary electrophysiological and optogenetic experiments in slices of mouse brain, designed to study how the PC microcircuits that involve the ASSN and LOT interact with BLA projections to shape PC activity. By either separately or simultaneously activating these inputs, we map the specific recruitment of excitation and inhibition across layers of PC neurons. These distinct afferences engage different excitation to inhibition (E/I) balances in PC neurons. In addition, we find that the inhibitory neuronal populations recruited by BLA and ASSN are presumably shared, but are not the same than the ones recruited by LOT.Finally, we use charbacol to investigate the effect of cholinergic moduluation on the induced PC responses. We show that this pharmalogical stimulation can reorganize afferent activity by differentially affecting inputs from BLA, ASSN and LOT.