Figure 7.

Localized administration of MK-801 into the mediodorsal nucleus of the thalamus results in changes similar to those observed following systemic drug administration. (A) Spectrogram of contralateral (upper) and ipsilateral (lower) mPFC LFP. Microdialysis pump was turned on after 10 min baseline recording for 5 min. Onset of activity similar to i.v. MK-801 injection was shortly after the pump was turned off in this particular experiment. Insets show characteristic LFP traces from highlighted regions of the ipsilateral signal. (B) Similar to systemic MK-801 administration, P1 component of the evoked response increased significantly after MD microinjection (p = 0.0218), while P2 did not change significantly. (C) PPF showed a tendency to decrease, but changes did not reach significance (individual animal data also shown). Ongoing LFP delta oscillation (D) changed similar to systemic MK-801 administration: the relative high frequency delta component significantly decreased (p = 0.0499) in the ipsilateral mPFC, and showed a tendency to decrease (p = 0.1761) in the contralateral mPFC.