The Periglomerular Cell of the Olfactory Bulb and its Role in Controlling Mitral Cell Spiking: A Computational Model

Abstract

Interneurons in the olfactory bulb are key elements of odor processing but their roles have not yet being fully understood. Two types of inhibitory interneurons, periglomerular and granule cells, act at two different levels within the olfactory bulb and may have different roles in coordinating the spiking of mitral cells, which are the principal output neurons of the olfactory bulb. In this work we introduce a reduced compartmental model of the periglomerular cell and use it to investigate its role on mitral cell spiking in a model of an elementary cell triad composed of these two cell types plus a granule cell. Our simulation results show that the periglomerular cell is more effective in inhibiting the mitral cell than the granule cell. Based on our results we predict that periglomerular and granule cells have different roles in the control of mitral cell spiking. The periglomerular cell would be the only one capable of completely inhibiting the mitral cell, and the activity decrease of the mitral cell through this inhibitory action would occur in a stepwise fashion depending on parameters of the periglomerular and granule cells as well as on the relative times of arrival of external stimuli to the three cells. The major role of the granule cell would be to facilitate the inhibitory action of the periglomerular cell by enlarging the range of parameters of the periglomerular cell which correspond to complete inhibition of the mitral cell. The combined action of the two interneurons would thus provide an efficient way of controling the instantaneous value of the firing rate of the mitral cell.

Fear is the mother of invention: anuran embryos exposed to predator cues alter life-history traits, post-hatching behaviour, and neuronal activity patterns

“…MCs were located below the GCs, in a single lamina, the MC layer, with their dendrites spanning the OB, and showed more depolarized resting potentials compared with GCs (−53.2±1.12 mV, N=13 versus −66.5± 1.55 mV, N=4; mixed model, F 1,15 =35.86, P<0.0001; Fig. 2B,C) in agreement with previous studies (Chen and Shepherd, 1997;Heyward et al, 2001;Scheidweiler et al, 2001;Arruda et al, 2013). In MCs, action potentials evoked by threshold current injections occurred with a long delay of up to 300 ms (N=13, Fig.…”

“…In MCs, action potentials evoked by threshold current injections occurred with a long delay of up to 300 ms (N=13, Fig. 2B showed that MCs of control tadpoles had an input resistance of 184.7±17.7 MΩ (N=13), which is significantly lower than that of GCs (315.5±7.9 MΩ, N=4; mixed model, F 1,14 =9.13, P=0.009), according to previous studies (Chen and Shepherd, 1997;Scheidweiler et al, 2001;Arruda et al, 2013;Heinbockel et al, 2004). The resting potential of MCs did not differ between control and treated tadpoles (respectively, −53.2±1.12 mV, N=13 and −54.2± 0.03 mV, N=13; mixed model, F 1,24 =0.43, P=0.52; Fig.…”

Role of intraglomerular circuits in shaping temporally structured responses to naturalistic inhalation-driven sensory input to the olfactory bulb

“…The network model was constrained by experimental data: in addition to incorporating biophysically realistic circuit elements, sensory input to the model OB network was derived from recordings of ORN inputs to the OB of intact rats, and an experimental dataset of presumptive MC recordings, evoked by the same naturalistic sniffing patterns used to drive the ORN responses, was used as a benchmark for evaluating model output. The use of input waveforms with naturalistic dynamics differs from the constant, pulsatile or sinusoidal inputs used in most earlier network models of olfactory processing (Arruda et al 2013;Bathellier et al 2006;Brody and Hopfield 2003;Davison et al 2003 ET-MC , maximum conductance for ET-MC synapse; g ET-PG ET , maximum conductance for ET-PG ET synapse; g PG ET -MC , maximum conductance for PG ET -MC synapse. In Fig.…”

Progress in defining heterogeneity and modeling periglomerular cells in the olfactory bulb

“…Furthermore, the model does not analyze the role periglomerular cells play in the olfactory information encoding process. These issues are further studied and discussed in the author's doctoral dissertation [36].…”

“…At present, research teams at the University of Sao Paulo, Brazil, and Zhejiang University are studying the functional mechanism of periglomerular cells under a complete olfactory bulb cell network model [36,37]. This study combines mitral cells and granule cells to build a three-layer olfactory network model that is then used to analyze the function of PG cells in olfactory bulb encoding.…”