ACh also modulates cortical circuits over longer time scales by influencing the plasticity of cortical circuits. In the auditory cortex, pairing sensory stimulation with stimulation of the basal forebrain results in a long-term reorganization of cortical receptive field structure, including a persistent shift in the receptive field towards the paired stimulus (Froemke et al., 2007). In the visual system, ACh facilitates ocular dominance plasticity in kittens via M1 mAChRs (Gu and Singer, 1993) and in rodents, the protein Lynx1 suppresses nicotinic signaling in primary visual cortex, and its removal promotes ocular dominance plasticity in older animals (Morishita et al., 2010).
