Nucleus striae terminalis lesions affect agonistic behavior of pigeons

Abstract

MARTIN RAMIREZ, J. AND J. D. DELIUS. Nucleus striae terminalis lesions affect agonistic behavior in pigeons. PHYSIOL. BEHAV. 22(5) [871][872][873][874][875] 1979.--Bilateral lesions of the nucleus striae terminalis suppressed the aggressive behavior shown by selected pigeons in response to a stick or the experimenter's hand being introduced into their home cage. Sham-operated animals did not show such an effect. Larger, accurately placed lesions led to an immediate suppression, smaller, less precisely placed lesions to a delayed effect. The suppression of aggression was accompanied by an increase in avoidance responses. The results are discussed in relation to suspected endocrinal activity of the nucleus striae terminalis and to the function this structure has in mammals. AggressionFear Lesions Nucleus striae terminalis Pigeon THE mammalian amygdala and its avian homologue, the archistriatum, have convincingly been shown to play an important role in the control of agonistic behavior, even if the precise nature of this role still needs to be further elucidated (for reviews see [9,19]). Situated as it is at a high level of the neuraxis the amygdala/archistriatum must exert its influence through its efferent pathways, the most important being the stria terminalis. For mammals there is evidence that the nuclear masses on which this pathway terminates are similarly involved in steering aggressive and fear responses even though there is still much uncertainty about how the stria terminalis influences their functioning. For birds the information available on this issue is still fragmentary but the pattern may grossly conform with that found in mammals. The present study focuses on the septal termination of the stria terminalis in the pigeon. In a previous investigation one of us [2] had found that electrical stimulation of the nucleus striae terminalis and its neighbourhood in awake, unrestrained gulls (Larus argentatus and fuscus) yielded threat behavior, sometimes accompanied by an increased tendency to respond aggressively to external stimuli for some fifteen minutes after the stimulation ended [7]. Histological peculiarities of the area in question, including an associated ependymal differentiation, suggested that the nucleus striae terminalis may be secreting into the lateral ventricle. Neurosecretory granules were later preliminarily verified in resorcin-fuchsin stained pigeon material. This led to the speculation that the release of a presumptive liquormone might have been responsible for the mood aftereffect [3]. We now simply began by examining the effect that lesions of the nucleus striae terminalis might have on the agonistic behavior of pigeons. METHODAdult homing pigeons of unknown sex were bought from local dealers. All had previous free-ranging experience. In the laboratory they were kept in standard 50x40x30 cm cages. Blinds between the cages reduced the visual contact among the animals. They were exposed to a 12 hr artificial light-12 hr dark cycle and to a nearly constant temperature of 18°C and had...