Cholinergic modulation of the medial prefrontal cortex: the role of nicotinic receptors in attention and regulation of neuronal activity

Abstract

Acetylcholine (ACh) release in the medial prefrontal cortex (mPFC) is crucial for normal cognitive performance. Despite the fact that many have studied how ACh affects neuronal processing in the mPFC and thereby influences attention behavior, there is still a lot unknown about how this occurs. Here we will review the evidence that cholinergic modulation of the mPFC plays a role in attention and we will summarize the current knowledge about the role between ACh receptors (AChRs) and behavior and how ACh receptor activation changes processing in the cortical microcircuitry. Recent evidence implicates fast phasic release of ACh in cue detection and attention. This review will focus mainly on the fast ionotropic nicotinic receptors and less on the metabotropic muscarinic receptors. Finally, we will review limitations of the existing studies and address how innovative technologies might push the field forward in order to gain understanding into the relation between ACh, neuronal activity and behavior.

Keywords: acetylcholine; attention; medial prefrontal cortex; neurophysiology; nicotinic receptors.

Figure 1

Summary of the main findings concerning nAChRs in the mPFC. Pyramidal cells in layer V and VI are directly modulated by nicotinic receptors, through α7 and β2* nAChRs respectively. In addition, the thalamic input to layer V is heavily modulated by β2* nAChRs. Interneurons in all layers contain nAChRs, although the distribution of homomeric and heteromeric receptor is different for different interneuron types and the different layers.