Schematic representation of our data interpretation.

<p><i>Case A: A mitral/tufted cell related to a glomerular unit receiving no input.</i> This cell exhibits neither a membrane potential slow oscillation (NoMPSO) nor a respiration-synchronized discharge pattern (NoS). Gl: glomerulus; M: mitral cell; Olf Cx: olfactory cortex. <i>Case B: A mitral/tufted cell related to a glomerular unit receiving a strong respiration-related input.</i> This cell exhibits a positive membrane potential slow oscillation (MPSO+) that exhibits an excitatory-simple-synchronized pattern (S+). This S+ spike pattern induces, via granular activation, lateral inhibition of the mitral/tufted cells connected to neighboring glomeruli. Therefore, this cell exhibits a negative membrane potential slow oscillation (MPSO-), which is associated with a suppressive-simple synchronized pattern (S-). Gr: granule cell. <i>Case C: A mitral/tufted cell related to a glomerular unit receiving a weak respiration-related input.</i> Because of the weak peripheral input, this cell is strongly influenced by the cellular excitability state, which is dependent on the characteristics of the animal’s internal state (such as neuromodulation and attention). The synergistic effect of the peripheral input and the intracellular excitability can result in several different types of membrane potential slow oscillations (MPSO+, -, sym or silent), which can induce different respiration-synchronized discharge patterns.