The afferent projection pattern from individual vibrissae follicles was related to the distribution of cytochrome oxidase (CO) dark cell clusters in the trigeminal sensory nuclei of adult rats to determine whether segregated primary afferent projections limit the extend of the topogaphic recognizations that can occur at the level of the brainstem on a short term basis after changes in sensory driven activity.The results indicate that the projections to all the brain stem trigeminal subnuclei, including the principal sensory nucleus and the three subdivisions of the spina trigeminal nucleus, are topographic; however, the extend to which label from subdivision to subdivision.In the principal sensory nucleus there is nearly a one to one relationship between the inputs from the vibressae follicles and the corresponding CO-dense clusters.Thus, little overlap in inputs from different vibrissae rows is likely.In contrast, in the parts interpolaris and, to a lasser extend, in the pars caudalis, inputs from individual vibrissae follicles extend beyond the appropriate CO-dark patch into adjacent whisker patches; thus inputs to these subdivisions from different vibrissae likely overlap more extensively.
Wild rodents, and especially rats, are significantly more difficult to handle, maintain and breed than laboratory rats and mice. They can be characterized as more skittish, neophobic and aggressive. While establishing a breeding colony of wild Norwegian rats (Rattus norvegicus) I developed some helpful devices and I will describe them here. In this paper I also describe the techniques for transporting animals between their home cages, separating them inside cages, and catching individuals that escape. These devices do not require any home cage modification. They may be modified for size. With size modification these devices may be used for handling animals in any type of laboratory cages. They may be used with all species of small mammals, for example, mice, gerbils, hamster, and opossums. They prove especially helpful when physical contact with humans is a problem (e.g. SPF conditions of breeding, and behavioral procedures that do not allow handling).