Are muscarinic acetylcholine receptors expressed by most parvalbumin-immunoreactive neurons in area MT of the macaque?
We find that, as in V1, most PV neurons in MT express m1 AChRs but, unlike in V1, it appears that so do most excitatory neurons. This provides support for V1 as a model of cholinergic modulation of inhibition in macaque visual cortex, but not of cholinergic modulation of visual cortical circuits in general. We also propose that ACh acting via m1 AChRs is a candidate underlying mechanism for the strong effects of attention on narrow-spiking neurons observed in behaving animals.
The findings indicate that for more vulnerable caregivers, the stress of caregiving leads to a loss of lymphocyte beta(2)-adrenergic receptors. This finding may be relevant to previous observations of clinically-relevant reduced immunity in highly stressed caregivers of AD patients.