Wulst efferents in the little owl Athene noctua

an investigation of projections to the optic tectum.

G. Casini, Vittorio Porciatti, G. Fontanesi, P. Bagnoli

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The efferent projections from the Wulst were studied in the little owl, Athene noctua, using anterograde migration of wheat-germ-agglutinin conjugated horseradish peroxidase (WGA-HRP). Wulst projections were distributed to telencephalic, diencephalic and mesencephalic targets in a general pattern similar to that previously described in other avian species. Our results on the organization of the Wulst-optic tectum pathway in the little owl reveal well defined and laminarly arranged terminal projections into the superficial tectal layers, with a distribution suggestive of topographical relationships between neurons of origin in the Wulst and termination fields in the optic tectum. In contrast to lateral-eyed birds, the little owl possesses conspicuous contralateral projections to the optic tectum. Ipsilateral and contralateral efferents are restricted to different tectal regions, i.e. ipsilateral projections to the caudo-dorsal and contralateral projections to the rostro-ventral optic tectum. In addition, the anterior and posterior Wulst differentially contribute to the ipsilateral and contralateral projections to the optic tectum. This differential organization of Wulst efferents, as well as the presence of substantial contralateral projections, might be related to the high degree of binocular overlap typical of frontal-eyed birds. At a functional level, electric potentials recorded in the optic tectum and evoked by visual stimulation showed that information from one eye can reach the ipsilateral optic tectum. After Wulst ablation, the amplitude of these potentials was significantly reduced, indicating that Wulst efferents may influence visually-evoked activity in the optic tectum.

Original languageEnglish
Pages (from-to)101-115
Number of pages15
JournalBrain, Behavior and Evolution
Volume39
Issue number2
StatePublished - Jan 1 1992
Externally publishedYes

Fingerprint

Athene noctua
Strigiformes
Superior Colliculi
optics
bird
ablation
wheat
Birds
Telencephalon
Photic Stimulation
Wheat Germ Agglutinins
wheat germ
birds
agglutinins
Horseradish Peroxidase
peroxidase
eyes
neurons
Neurons

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Neuroscience(all)

Cite this

Wulst efferents in the little owl Athene noctua : an investigation of projections to the optic tectum. / Casini, G.; Porciatti, Vittorio; Fontanesi, G.; Bagnoli, P.

In: Brain, Behavior and Evolution, Vol. 39, No. 2, 01.01.1992, p. 101-115.

Research output: Contribution to journalArticle

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