Experimental studies on hatching behavior in the chick. I. Thoracic spinal gaps

✍ Scribed by Oppenheim, Ronald ;Narayanan, C. H.

• Publisher: John Wiley and Sons
• Year: 1968
• Tongue: English
• Weight: 666 KB
• Volume: 168
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401680309

✦ Synopsis

Using microsurgical techniques spinal "gaps" were made in the thoracic level of chick embryos at two days of incubation by removing small lengths of neural tissue. These same embryos were then examined in detail between 17 days and hatching for any behavioral modifications.

The frequency and patterns of various movements anterior to the gap were found to be similar to control embryos. Leg movements were also found to be equal in number to those of the controls. Operated embryos, while being able to orient correctly in the egg and to pip the shell, were not able to hatch on their own. This was due to an inability of these embryos to coordinate movements of the legs with movements anterior to the spinal gap, and to the absence of vigorous. stemming movements of the legs against the shell. This prohibited them from cracking and rotating around the shell and hence from hatching.

Three of the spinal embryos which were artificially hatched (pulled out of shell) were not able to stand or walk after two days. However, the legs of these chicks did show "spontaneous" alternating kicking movements and were responsive to stimulation.