title: The organization of the nucleus basalis-neostriatum complex of the mallard (Anas platyrhynchos L.) and its connections with the archistriatum and the paleostriatum complex.
abstract: The pattern of connections between the nucleus basalis, neostriatum, hyperstriatum ventrale, paleostriatum complex and archistriatum in the mallard has been analysed using Nissl material and a combination of neuroanatomical tracing procedures (autoradiography, horseradish peroxidase and horseradish peroxidase-wheat germ agglutinin histochemistry, lesion/degeneration technique). The frontal part of the mallard's telencephalon is characterized by its multilayered organization and the predominantly vertical arrangement of the connecting fiber systems. The nucleus basalis, endstation of the ascending sensory trigeminal system, is a large laminar cell area with a dorsal and a ventral layer. The overlying neostriatum frontale can be subdivided into a medial, a dorsal and a ventral intermediate, and a lateral area. The nucleus basalis has distinct connections with the ventral layer and sparse connections with the dorsal layer of the intermediate neostriatum, and abundant reciprocal connections with the ventral layer of the hyperstriatum ventrale. The ventral intermediate neostriatum also has reciprocal connections with the hyperstriatum ventrale; its projections overlap partly with those from the nucleus basalis. The ventral layer of the intermediate neostriatum frontale has a distinct projection upon the paleostriatum augmentatum. The dorsal layer sends fibers to the lateral neostriatum, to the rostral "sensorimotor" part of the archistriatum and to the lateral zone of the lobus parolfactorius. Another source of archistriatal afferents is the paleostriatum ventrale, an area that may also send fibers to the brainstem. Figure 21 summarizes the connections described in this paper. The functional significance of this organization is discussed in relation to its possible role in the guidance of pecking and other feeding behaviors in the mallard. Differences in the organization of the systems in pigeon and mallard are related to the differing degrees of visual and tactile (trigeminal) contributions to feeding in the two birds. It is suggested that the pattern of reciprocal connections between the hyperstriatum ventrale and the nucleus basalis and ventral intermediate neostriatum frontale forms the neuroanatomical substrate for a "comparator-system".
mesh_terms: D000818:Animals; D001345:Autoradiography; D001479:Basal Ganglia / Q000033:anatomy & histology* / Q000502:physiology; D003342:Corpus Striatum / Q000033:anatomy & histology; D004372:Ducks / Q000033:anatomy & histology*; D006735:Horseradish Peroxidase; D007930:Leucine; D008297:Male; D009434:Neural Pathways / Q000033:anatomy & histology; D013194:Staining and Labeling / Q000379:methods; D013377:Substantia Innominata / Q000033:anatomy & histology; D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins
chemical_list: D018998:Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; D014909:Wheat Germ Agglutinins; D006735:Horseradish Peroxidase; D007930:Leucine