Effects of hypocretin and norepinephrine interaction in bed nucleus of the stria terminalis on arterial pressure

J.Ciriello, M.M. Caverson and Z. Li

The bed nucleus of the stria terminalis is a limbic structure that is activated stressful stimuli. The autors wanted to address whether hypocretin-1 (hct-1) and norepinephrine (NE) are playing a role in the BST to control cardiovascular responses. They used microinjection injection technique in anesthetized wistar rats to examine the question. They found that in response to glutamate (glu) there were decreases in blood presssure (BP) and heart rate (HR). I response to both NE and hct-1the BST response to glu was blunted. They also looked at whether GABAergic neurons in the BST is mediating the inhibitory responses. They injected bicuculline and phaclofen into BST.They found that Bic but not phaclophen blocked the glu responses. Next that looked at adrenergic receptor blockade with yohimibine (a2AR) and a1AR receptor. antagonist. They found that a2AR blocked Hct-1 and NE depressor responses. 

Conclusion: HCT-1 may cause the the release of NE. This in turn may activate GABAergic neurons in the BST in response to stressful stimuli.

-MD