Transient aphagia produced following bilateral destruction of the lateral hypothalamic area and quinto-frontal tract of chicks

Abstract

Six groups of broiler chicks, Gallus domesticus, sustained bilateral lesions to specific neural structures residing in the lateral hypothalamic and thalamic areas. In contrast to past data reported for the albino rat, the pigeon, Columba livia and barbary dove, Streptopelia risoria, bilateral destruction of the chick lateral hypothalamic area (LHy), quinto-frontal tract (QF), and stratum cellulare externum (SCE) resulted in transient aphagia and rapid recovery of lost body weight. Similarly, bilateral destruction of the nucleus reticularis superior (RS) and nucleus intercalatus (ICT) resulted in a temporary 1–3 day period of aphagia with body weight returning to pre-operative levels in approximately 4 days. Bilateral destruction of the ansa lenticularis (AL) resulted in a more prolonged period of aphagia (4 days) and an average 8-day period to recover lost body weight. Additional data suggest that more persistent aphagia can be induced following lesions to the posterior hypothalamus and midbrain. Specifically, bilateral lesions which destroyed the following combination of neural structures resulted in prolonged aphagia: AL, QF and posterior LHy; AL and posterior nucleus of the AL (ALp); and AL, ALp and QF. It is suggested that the AL and ALp contain neurons which are part of a more complex system that modulates or controls motor activity and feeding behavior in birds.