A fundamental problem in neuroscience, to which Prof. Segundo has made seminal contributions, is to understand how action
potentials represent events in the external world. The aim of this paper is to review the issue of neural coding in the context
of the rodent whiskers, an increasingly popular model system. Key issues we consider are: the role of spike timing; mechanisms
of spike timing; decoding and context-dependence. Significant insight has come from the development of rigorous, information
theoretic frameworks for tackling these questions, in conjunction with suitably designed experiments. We review both the theory
and experimental studies. In contrast to the classical view that neurons are noisy and unreliable, it is becoming clear that
many neurons in the subcortical whisker pathway are remarkably reliable and, by virtue of spike timing with millisecond-precision,
have high bandwidth for conveying sensory information. In this way, even small (~200 neuron) subcortical modules are able
to support the sensory processing underlying sophisticated whisker-dependent behaviours. Future work on neural coding in cortex
will need to consider new findings that responses are highly dependent on context, including behavioural and internal states.
Keywords Neural coding - Barrel cortex - Information theory - Vibrissa
This article is part of a special issue on Neuronal Dynamics of Sensory Coding.