Pearson correlations to assess the relationship between anxiety-like behavior (i.e., average center distance traveled) and the relative concentrations of histamine (a) and tyrosine (b). There were positive correlations between the distance score and histamine (r = 0.55, p = 0.0045), and tyrosine (r = 0.21, p = 0.177), indicating that a higher anxiety-like state was linked to lower histamine and tyrosine concentrations