A Stereotaxic Atlas of the Brain of the Chick (Gallus domesticus)

Nine brains taken from chicks two weeks of age were used for the development of this atlas. Each chick was first anesthetized with an intravenous (IV) injection of Chloropent2 (1.8 ml/kg). Chicks were then perfused via the heart with 90 ml physiological saline followed by 90 ml Heidenhain\u27s3 solution. Each head was then positioned in a stereotaxic instrument as described in the previous section and three stainless steel (SS) insect pins (#2) were implanted in each brain at known coordinates. In the case of the brains used to construct the cross- sectional atlas plates, two pins were implanted horizontal to the base of the stereotaxic instrument. Each was inserted into the forebrain and the pins exited either the brainstem or the cerebellum. The third pin was inserted vertical to the base of the stereotaxic instrument. The brains used to construct the sagittal atlas plates had two pins inserted horizontally and one pin inserted vertically to the stereotaxic instrument. The horizontal pins entered the right side of the brain and exited the left side. The brains used for the horizontal plates had two pins inserted vertically and one pin horizontally. The latter entered the forebrain and exited the brainstem