Figure 2. Involvement of cholinergic receptor activation in the novelty exploration-induced reversal of stress effects.
A, the ability of novelty exploration to reverse the stress-induced LTP impairment was prevented when rats were injected with the cholinergic receptor antagonist atropine (30 mg kg−1, i.p.) 20 min before being allowed explore a novel cage (NC). Atropine did not significantly affect LTP in slices from unstressed-home cage (US-HC), unstressed-novel cage (US-NC) and stressed-home cage (S-HC) rats. B, comparison of the magnitude of LTP 50 min after HFS. C, atropine blocked novelty exploration-induced reversal of stress-induced facilitation of LTD. Atropine did not significantly affect LTD in slices from US-HC, US-NC and S-HC rats. D, comparison of the magnitude of LTD 50 min after LFS. E, representative immunoblots showing ERK1/2 phosphorylation after stress plus NC and HC among atropine-treated rats. The corresponding densitometric analysis is shown in F.