To the best of our knowledge, this is the first report demonstrating the negative correlation between brain levels of GSH and the severity of negative symptoms in schizophrenia.
Correlation analysis showed no relationship between brain levels of AVT and IT in females, masculinized females or males that do not display same-sex mating behaviour.
For organic Hg brain levels, we found a linear relationship between the logarithm of organic Hg brain levels and the logarithm of MeHg dose (after adding 0.l to avoid taking the logarithm of 0), and our final model included three terms: log(MeHg dose + 0.1), any Hg vapor exposure, and their interaction.
Consistent with previous reports [38] [41] and with an interaction of copper in our experimental system, we found that there is a significant inverse correlation between brain APP levels and both pellet (p = 0.0005) and supernatant (p = 0.02) copper levels (Figure 7) in the untreated transgenic mice.
Prior preclinical and clinical work has demonstrated an inverted U-shaped relation between brain dopamine levels and cognition [ 58],[ 59], such that both excessive and insufficient dopamine levels impair cognitive performance.
There were no correlations between brain GSH levels and scores on any cognitive performance test except Trail Making Test part A. These results suggest that GSH levels in the posterior medial frontal cortex may be related to negative symptoms in schizophrenic patients.
Indeed, there was no correlation in this study between brain BE levels and plasma testosterone concentrations, although this research is limited by the absence of variability of BE or testosterone concentration between the 11 inbred strains.
Correlations between brain BE levels and plasma testosterone concentrations in the 11 inbred mouse strains (each strain is represented by the mean of five animals for biological variables) were determined by Spearman rank-order correlation analyses.
In addition, there was no correlation between brain BE levels and plasma testosterone concentration when the analysis was conducted on the eleven different inbred strains including the same N and H males contributing to the present study (ρ spearman = 0.09, P>0.1).
However, we were surprised to observe a different relationship between brain glucose levels and insulin doses.
