Origin and distribution of noradrenergic innervation in the habenula: a neurochemical study.
The distribution of norepinephrine (NE) was chemically mapped in discrete regions of the rat habenula (Hb). In addition, the contribution of both peripheral sympathetic and central noradrenergic sources to habenula NE was quantified following selective deafferentations. It was found that NE is distributed hetereogeneously in discrete Hb regions. Furthermore, it was demonstrated that after superior cervical ganglionectomy a small (26%) but significant (P less than 0.05) decrease in NE occurred only in the medial Hb (MHb), while NE in the lateral Hb (LHb) remained unaltered. In contrast, deafferentation of central noradrenergic innervation, such as lesions in the ascending dorsal noradrenergic bundle (DNB), caused a marked decrease in NE in both MHb (53%) and LHb (50%). Lesioning the dorsal longitudinal fasciculus resulted in NE loss in both MHb and LHb by 31%. These data corroborate the histofluorescent demonstration of the noradrenergic innervation of the Hb.
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D004027:Diencephalon / Q000502:physiology*; D006651:Histocytochemistry; D008297:Male; D009474:Neurons / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013238:Stereotaxic Techniques
D009638:Norepinephrine