5 09 2015

After so much time and stress trying to get the methods working, Danielle eventually came up with some plausible (if untidy, not least due to the many dead cells caused by my still-poor fixation) delta-fos staining.

But was it really picking up anything true and biologically interesting in the mouse brains?

First encouraging signs: right and left hemisphere dorsal striatal counts covaried, as did right and left hemisphere nucleus accumbens counts. Also, counts in four different caudate-putamen regions covaried with each other (all done controlling for dead cell counts as they could easily create or obscure relationships). So if we didn’t find anything, we now felt cautiously sure the staining protocol itself was not at fault.

Nothing in the caudate putamen: no relationships with behaviour at all. But in the nucleus accumbens, there was significantly higher delta-fos activity (indicating more long-term neuronal activation) in the more intense stereotypers! This fits with Simona Cabib‘s ideas of a few years ago, although not with (wishful-thinking-based?) arguments that these mice are perseverative because of dorsal stratal changes. Very cool anyway.