Interaction between catecholaminergic terminals and urocortinergic neurons in the Edinger-Westphal nucleus in the rat.
Central stress regulatory pathways utilize various neurotransmitters/neuropeptides, such as urocortin (Ucn) and catecholamines. Ucn is most abundantly expressed in the Edinger-Westphal nucleus (E-WN), co-distributed with catecholaminergic terminals. Acute stress recruits E-WN neurons, and ascending catecholaminergic pathways also contribute to the activation of various brain areas in response to stress. We hypothesized that catecholamine and Ucn interactions in the E-WN mediated the recruitment of these neurons in response to stress. Using double-labeling immunohistochemistry, we found close appositions between urocortin-immunoreactive nervous structures and dopaminergic terminals, however, depletion of them had no effect on the activation pattern of E-WN neurons upon acute immune challenge. From these results we conclude that dopaminergic terminals innervating E-WN Ucn neurons do not play a major role in mediating the responses of E-WN neurons upon acute immune challenge.
D000818:Animals; D002395:Catecholamines / Q000032:analysis / Q000378:metabolism*; D003346:Corticotropin-Releasing Hormone / Q000032:analysis / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000737:chemistry / Q000378:metabolism*; D009802:Oculomotor Nerve / Q000737:chemistry / Q000378:metabolism; D017729:Presynaptic Terminals / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013312:Stress, Physiological / Q000378:metabolism; D054832:Urocortins
D002395:Catecholamines; D054832:Urocortins; D003346:Corticotropin-Releasing Hormone