How silent is the brain: is there a “dark matter” problem in neuroscience?
- 1.2k Downloads
Evidence from a variety of recording methods suggests that many areas of the brain are far more sparsely active than commonly thought. Here, we review experimental findings pointing to the existence of neurons which fire action potentials rarely or only to very specific stimuli. Because such neurons would be difficult to detect with the most common method of monitoring neural activity in vivo—extracellular electrode recording—they could be referred to as “dark neurons,” in analogy to the astrophysical observation that much of the matter in the universe is undetectable, or dark. In addition to discussing the evidence for largely silent neurons, we review technical advances that will ultimately answer the question: how silent is the brain?
KeywordsBlood Oxygenation Level Dependent Primary Visual Cortex Extracellular Recording Multielectrode Array Awake Animal
We thank Sam Wang for fruitful discussions during the preparation of this manuscript, and two anonymous reviewers for their helpful comments. We also thank Joe Goodhouse and Michael J. Berry II for allowing us to use the figure.
- Abeles M (1991) Corticonics: neural circuits of the cerebral cortex. Cambridge University Press, CambridgeGoogle Scholar
- Rieke F (1997) Spikes: exploring the neural code. MIT Press, CambridgeGoogle Scholar
- Rosenblatt F (1962) Principles of neurodynamics. Spartan, New YorkGoogle Scholar
- Sholl DA (1956) The organization of the cerebral cortex. Methuen, LondonGoogle Scholar
- Singer W (1999) Neuronal synchrony: a versatile code for the definition of relations? Neuron 24:49–65, 111–125Google Scholar