Behavioral effects of lesions of the central noradrenergic bundles in the rat.
Rats with bilateral lesions of the dorsal noradrenergic bundle (DB) or of the ventral noradrenergic bundle (VB) were studied in different behavioral test situations. All lesioned animals defecate less than sham operated animals in the open-field (OF) or in the conditioning apparatus described by Henderson [16]. These data suggest a decrease of emotional reactivity in lesioned animals. However, the DB rats' level of exploration was higher than that of VB rats. No effect on the amplitude of the startle response has been shown after lesioning. The lesions of the dorsal noradrenergic bundle induce a decrease in cortical noradrenaline hypothalamic catecholamines. The lesions of the ventral noradrenergic bundle induce a decrease in hypothalamic catecholamines without change in the cortex. These results do not support the postulation [22] that the dorsal bundle and the ventral bundle play an opposite role in behavior. Yet, a selective participation of each bundle is suggested in modulating responses to novel environments and anxiogenic situations.
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D004609:Eliminative Behavior, Animal / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009638:Norepinephrine / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013216:Reflex, Startle / Q000502:physiology
D009638:Norepinephrine