“…These cells release a range of chemokines and cytokines which allow for bidirectional communication between the brain and immune system. There is now very good evidence to suggest that cytokines directly modulate HPA axis activity (Dunn, 2000;Jara et al, 2006;Mastorakos and Ilias, 2006;Mulla and Buckingham, 1999;Rivest, 2001;Savastano et al, 1994;Torpy and Chrousos, 1996;Turnbull and Rivier, 1999), anxiety-and depression-related behaviour (Anisman and Merali, 1999;Breese et al, 2008;Connor and Leonard, 1998;Craddock and Thomas, 2006;Leonard, 2001;Leonard, 2006;Nautiyal et al, 2008;O'Brien et al, 2004;Schiepers et al, 2005;Silverman et al, 2007;Wichers and Maes, 2002) and pain (McMahon et al, 2005;Moalem and Tracey, 2006;Sommer and Kress, 2004;Thacker et al, 2007;Watkins et al, 2003;Wieseler-Frank et al, 2005a;Wieseler-Frank et al, 2005b). Our recent work (Roche et al, 2006;Roche et al, 2008), and that of others (Croci et al, 2003;Panikashvili et al, 2001;Smith et al, 2000;Smith et al, 2001a;Smith et al, 2001b), has demonstrated a role for the endocannabinoid system in regulating peripheral and brain cytokine responses to immune challenge/stress in vivo.…”