(A) Mean (±SEM) Span and Best Trial after Sham, Saline, and after M/B infusions into the mPFC. Infusions of M/B into the mPFC significantly impaired Mean Span and Best Trial, replicating previous findings that the mPFC is critical for OST performance. Interestingly, Saline infusions also caused a significant impairment relative to Sham infusions, demonstrating that the Saline control is not, itself, entirely inert; (B) Mean (±SEM) Span and Best Trial after Sham, Saline, and M/B infusions into the mdThal. Infusions of M/B into the mdThal significantly reduced both Mean Span and Best Trial, demonstrating that the mdThal is critical for intact OST performance. (C) Mean (±SEM) Span and Best Trial after Saline infusions, Ipsilateral M/B infusions, or disconnection of the mPFC and mdThal. Disconnection caused a significant impairment in both Mean Span and Best Trial, whereas Ipsilateral infusions caused a significant impairment only in Mean Span relative to Saline, although both Mean Span and Best Trial were impaired relative to Sham infusions. The results are not inconsistent with the interpretation that mPFC-mdThal connections are necessary for the OST, but the impairment in the Ipsilateral control condition means other explanations cannot be ruled out.
