Similarities in structure have also occasioned comparisons between the function of the olfactory bulb and the thalamus (Kay

and Sherman, 2007). In the mammalian spinal cord it has been shown that genetically silencing certain groups of neurons can have profound behavioral consequences (Gosgnach et al., 2006, Lanuza et al., 2004 and Zhang et al., 2008). For example, silencing excitatory V3a interneurons compromises the rhythmicity and stability of locomotor RO4929097 solubility dmso outputs (Zhang et al., 2008). The coherence of spiking activity in our model network was also similarly compromised by the removal of excitatory interactions. The sequence of bursts generated by the networks constructed here Selleck BIBW2992 qualitatively resembles the kind of dynamics seen in networks that exhibit a form of competition termed winnerless competition (WLC) (Rabinovich et al., 2001). These patterns of activity have been hypothesized to be heteroclinic orbits that connect saddle fixed points or saddle limit cycles in the system’s state space (Rabinovich, 2006). The stability of these sequences and the capacity

of the network to generate sequential patterns have been analyzed in detail. However, the relationship between the structure of the network and the resulting patterns of activation are not yet known. Ahn et al. (2010) derive a computationally efficient and analytically tractable discrete time dynamical system that accurately replicates the dynamics of a more complex Hodgkin-Huxley-type neuronal network. The discrete time model predicts which group of neurons will spike next given that a specific group of neurons spiked during a previous epoch. The constraints imposed on the model include the Ca2+ concentration in the cells, the ionic conductances, the neuronal thresholds, and the number of inputs each neuron receives from a group that spiked in a preceding epoch. Our approach is complementary to that of Ahn et al. (2010). We use a global descriptor Idoxuridine of the network structure (its colorings) to deduce the set of all possible solutions of the system

(a solution is valid only if it respects the coloring of the network). Additional constraints such as the directed connections between neurons, asymmetries in intrinsic parameters, and Ca2+ concentration in the cell (Ahn et al., 2010) can make specific solutions stable. In this study we used the insect olfactory system to derive a structure-dynamics relationship in neuronal networks. This relationship can be tested in other well-charted networks such as central pattern generators (Marder and Calabrese, 1996). In the stomatogastric ganglion, where reciprocal inhibition is ubiquitous and implicated in generating periodic patterns (Getting, 1989 and Marder and Calabrese, 1996), alternating bursts are produced by a number of different mechanisms.