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We believe that names have a powerful influence on the experiments we do and the way in which we think. For this reason, and in the light of new evidence about the function and evolution of the vertebrate brain, an international consortium of neuroscientists has reconsidered the traditional, 100-year-old terminology that is used to describe the avian(More)
The standard nomenclature that has been used for many telencephalic and related brainstem structures in birds is based on flawed assumptions of homology to mammals. In particular, the outdated terminology implies that most of the avian telencephalon is a hypertrophied basal ganglia, when it is now clear that most of the avian telencephalon is(More)
The visual wulst is the telencephalic target of the thalamofugal visual pathway of birds, and thus the avian equivalent of the striate cortex of mammals. The anterograde tracer Phaseolus vulgaris leucoagglutinin was used to follow the intratelencephalic connections of the major constituents of the visual wulst in pigeons. In particular, efferent pathways(More)
The avian wulst, a laminated "bulge" in the dorsal telencephalon, contains several distinct regions. The posterolateral portion (visual wulst) has been proposed to be an avian equivalent of the mammalian striate cortex. The present study examines specific neurotransmitters and neuropeptides within the visual wulst by immunohistochemical techniques. Antisera(More)
The pigeon caudolateral neostriatum (NCL) shares a dopaminergic innervation with mammalian frontal cortical areas and is implicated in the regulation of avian cognitive behavior. Retrograde tracing methods were used to identify forebrain projections to NCL and to suggest a possible role of this area in mediating spatial behavior. NCL receives telencephalic(More)
Birds and primates are vertebrates that possess the most advanced, efficient visual systems. Although lineages leading to these two classes were separated about 300 million years ago, there are striking similarities in their underlying neural mechanisms for visual processing. This paper discusses such similarities with special emphasis on the visual(More)
The ectostriatum is a major visual component of the avian telencephalon. The core region of the ectostriatum (Ec) receives visual input from the optic tectum through thalamic nuclei. In the present study, the efferent projections of the ectostriatum were investigated by using the anterograde tracers Phaseolus vulgaris leucoagglutinin and biotinylated(More)
The avian nucleus rotundus, a nucleus that appears to be homologous to the inferior/ caudal pulvinar of mammals, is the major target of an ascending retino-tecto-thalamic pathway. Further clarification of the inputs to the rotundus and their functional properties will contribute to our understanding of the fundamental role of the ascending tectal inputs to(More)
In the nonmammalian telencephalon, there are neuronal populations corresponding to cell groups in the neocortex of mammals in terms of connections, single unit-responses, chemical content, and functions. Some of these populations in nonmammals, however, are organized in a nonlaminar, rather than laminar fashion. These observations may prompt a reassessment(More)
Previous work has shown that the avian retina receives two types of centrifugal fibers from the brain. These types can be distinguished based on the size and the morphology of their terminal endings and have been termed convergent and divergent. The centrifugal fibers arise from the isthmooptic nucleus (ION) and the surrounding ectopic cell region (ECR). We(More)