Use of brainstem flat-mounts for visualizing DiI-filled axons in the developing rodent visual system.
The lipophilic carbocyanine fluorescent label DiI was injected in one eye of aldehyde-fixed embryonic or postnatal hamsters and the brains were examined using flat-mounts of the chiasm region, of the lateral surface of the brainstem, or of the midbrain tectum. Single axons could be discerned within the optic nerves and along the optic tract. Many fibers were tipped by growth cones, ending at various levels of the brainstem. Fine details of retinofugal axon morphology, including varicosities, branch-points and filopodial extensions on growth cones were visible in the flat-mounts. Such preparations allow a high-resolution view of labeled axons which course near the surface of the brain. It is possible, with this method, to simultaneously examine the morphogenesis of multiple collateral arbors on single fibers which project to more than one terminal zone.
Erzurumlu
R
R
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139.
Jhaveri
S
S
Schneider
G E
GE
D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000648:ultrastructure*; D001933:Brain Stem / Q000648:ultrastructure*; D002232:Carbocyanines; D006224:Cricetinae / Q000196:embryology; D005333:Fetus; D006652:Histological Techniques; D012160:Retina / Q000502:physiology; D009435:Synaptic Transmission; D014795:Visual Pathways / Q000648:ultrastructure*
D002232:Carbocyanines; C024286:3,3'-dioctadecylindocarbocyanine; C015843:3,3'-dipropyloxadicarbocyanine