Aims: 

Soon after hatching the young chicken (Gallus domesticus L.) can walk, see, chirp, and feed itself, like all precocial avians. These behavioural actions require the early development of CNS areas responsible for basic motor actions, perception and homeostasis. Previous studies revealed that the extracellular matrix (ECM) around neurons highly influence their activity and vice-versa. We investigated the development of ECM assembly around neurons related to motor coordination in the brainstem of chicken embryos, to relate its first areas of appearance to functions mentioned.

Methods: 

We gained embryos by aborting incubation at E7-9-11 developmental ages. After fixation and paraffin embedding, 10 mm horizontal sections were made. ECM components were histochemically and immunohistochemically detected, using WFA, bHABP, Cat-315, TN-R and HAPLN-1. Reactions were visualized by DAB.

Results: 

Aggrecan labeled in hypothalamus, medial vestibular nucleus and central grey matter of mesencephalon at E7 stage. At E9-11 stages labeling inforced and appeared in the reticular formation. WFA stained at E7 in the vestibular nuclei. In E9-11 visuomotor nuclei, reticular formation, hypoglossus and spinal trigeminal nucleus, hypothalamus and optic tectum also stained. HAPLN1 labeled at E11 first, in the medial vestibular nucleus, but none before. HA was positive at E7 in visuomotor nuclei, hypothalamus, descending vestibular nucleus, at E9-11 the medial and descending vestibular nuclei, motor nucleus of vagus, cerebellum, hypoglossus nucleus and inferior olive.

Conclusions: 

By these findings we may conclude that brainstem areas responsible for posture and gaze, feeding, homeostasis, motor and psychomotor, and sensory functions develop the strongest perineuronal net (PNN), which might be the character of precocial birds.

Support: 

MTA TKI 242, OTKA K67641