Table 4.

The largest six clusters of references in the co-citation network.

Cluster	Size	Mean silhouette	Mean year	Label (LLR algorithm)	Representative reference
0	70	0.725	2014	Cytokines	Bravo et al. (42)
1	51	0.658	2010	Inflammation	Bercik et al. (43)
2	40	0.816	2007	Forced swim test	Desbonnet et al. (44)
4	21	0.981	2004	Chronic fatigue syndrome	Maes et al. (45)
12	7	0.989	2010	Lipopolysaccharide (LPS)	Maes et al. (46)
21	3	0.968	2011	Gastrointestinal	Finegold et al. (47)

“LLR” means log-likelihood ratio.