Morphological and functional changes in the retinotectal system of the pigeon during the early posthatching period

Paola Bagnoli, Vittorio Porciatti, Gigliola Fontanesi, Laura Sebastiani

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Anterograde transport of either HRP or wheat germ agglutinin-conjugated HRP was used to study the posthatching development of the retinotectal connection in the pigeon. The functional maturation of the retinotectal system was also investigated by recording electroretinographic (ERG) and tectal evoked (TEP) responses to either flash or pattern stimuli. Two main morphological changes occurred in the retinotectal system during the first 6 days after hatching: (1) an ipsilateral retinofugal component that was present at hatching disappeared and (2) the outer tectal layers were progressively limited to the stratum griseum et fibrosum superficiale of the dorsolateral tectal quadrant. During the early posthatching period, at the same developmental stage at which an ERG to unpatterned or patterned stimulation could first be recorded, a visually evoked response could be elicited in the contralateral optic tectum. Therefore, the retina and optic tectum seem to start functioning simultaneously, the limiting factor being the late maturation of photosensitive lamellae in the outer segments of the developing photoreceptors. During the first 20 days posthatching, the retinotectal system undergoes extensive development as revealed by latency and amplitude changes of the visually evoked potentials. We suggest that the pigeon visual system serves as a useful model for studies concerning visual development and plasticity.

Original languageEnglish (US)
Pages (from-to)400-411
Number of pages12
JournalJournal of Comparative Neurology
Issue number3
StatePublished - Feb 15 1987
Externally publishedYes


  • avian
  • late maturation
  • retinofugal pathway
  • visual system

ASJC Scopus subject areas

  • Neuroscience(all)


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