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Updated: Apr 18, 2026

Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention
Published on: September 11, 2017
Cholinergic control of gamma power in the midbrain spatial attention network
Astra S Bryant1, C Alex Goddard2, John R Huguenard3
1Department of Neurobiology, Neurosciences Program, and astra.bryant@gmail.com.
Abstract:
The modulation of gamma power (25-90 Hz) is associated with attention and has been observed across species and brain areas. However, mechanisms that control these modulations are poorly understood. The midbrain spatial attention network in birds generates high-amplitude gamma oscillations in the local field potential that are thought to represent the highest priority location for attention. Here we explore, in midbrain slices from chickens, mechanisms that regulate the power of these oscillations, using high-resolution techniques including intracellular recordings from neurons targeted by calcium imaging. The results identify a specific subtype of neuron, expressing non-α7 nicotinic acetylcholine receptors, that directly drives inhibition in the gamma-generating circuit and switches the network into a primed state capable of producing high-amplitude oscillations. The special properties of this mechanism enable rapid, persistent changes in gamma power. The brain may employ this mechanism wherever rapid modulations of gamma power are critical to information processing.
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