Neuronal firing in anterior cingulate neurons changes modes across trials in single states of multitrial reward schedules
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The recorded responses of single neurons often vary considerably in the numbers of spikes emitted across repeats of a single experimental condition. Because of this irregularity and for theoretical convenience the responses are often approximated using a Poisson process. However, it has been frequently pointed out that many details of the responses, including the distribution of spike counts across similar trials, are not consistent with a Poisson process, even an inhomogeneous one. Wiener and Richmond (2003, J Neurosci 23:2394–2406) showed that the spike count distributions could usually be fitted nicely by mixtures of a few (1–3) Poisson distributions, a step they regarded as a computational convenience. Now, we find that a substantial proportion (47%) of the neuronal responses from anterior cingulate cortex, which we conceptualize as part of a system related to the balance between work and reward, have responses with multimodal firing rate distributions. When these distributions are modeled as mixtures of Poisson distributions, the proportions of the different Poisson distributions are related to behavioral state, and might be related to cognitive factors. This suggests that the neurons undergo behaviorally-related mode changes.
KeywordsNeural coding Response variability Anterior cingulate Single unit recording Rhesus monkey
This work is supported by AIST/Japan and IRP/NIMH/USA. BJR’s travel to AIST was supported by JSPS fellowship.
- Bowman EM, Aigner TG, Richmond BJ (1996) Neural signals in the monkey ventral striatum related to motivation for juice and cocaine rewards. J Neurophysiol 75:1061–1073Google Scholar
- Ihaka R, Gentleman R (1996) R: a language for data analysis and graphics. J Comput Graph Stat 5:299–314Google Scholar
- Loader C (1999) Local regression and likelihood. Springer, Berlin Heidelberg New YorkGoogle Scholar
- Mizuhiki T, Richmond BJ, Shidara M (2003) Single neurons in anterior insular cortex of Rhesus monkey related to reward predictability during multi-trial reward schedules. In: Society for Neuroscience (2003) 2003 Abstract Viewer and Itinerary Planner. Society for Neuroscience, Washington DC, Program No. 293.14Google Scholar
- Mizuhiki T, Richmond BJ, Shidara M (2004) Neuronal firing in several dopamine rich brain regions exhibits mode switching across trials in single states of multitrial reward schedules. In: Society for Neuroscience (2004) 2004 Abstract Viewer and Itinerary Planner. Society for Neuroscience, Washington DC, Program No. 439.7Google Scholar
- Shidara M, Aigner TG, Richmond BJ (1998) Neural signals in the monkey ventral striatum related to progress through a predictable series of trials. J Neurosci 18:2613–2625Google Scholar
- Stern EA, Kincaid AE, Wilson CJ (1997) Spontaneous subthreshold membrane potential fluctuations and action potential variability of rat corticostriatal and striatal neurons in vivo. J Neurophysiol 77:1607–1715Google Scholar
- Wiener MC, Richmond BJ (2003) Decoding spike trains instant by instant using order statistics and the mixture-of-Poisson model. J Neurosci 23:2394–2406Google Scholar
- Wilson CJ (1995) The contribution of cortical neurons to the firing pattern of striatal spiny neurons. In: Houk JC, Davis JL, Beiser DG (eds) Models of information processing in the basal ganglia. MIT, Cambridge, MA, pp 29–50Google Scholar