Specific labeling densities were associated with avian equivalents of the mammalian pyramidal system (hyperstriatum accessorium; archistriatum intermedium and Tractus occipitomesencephalicus) and extrapyramidal system (paleostriatum augmentatum, paleostriatum primitivum and lobus parolfactorius), as well as several limbic structures (hippocampal formation, nucleus taeniae and the caudal part of the archistriatum). 
Food intake was decreased by injections near the lateral septal organ and the anterior portion of both the nucleus reticularis superior, pars dorsalis, and the Tractus occipitomesencephalicus.
The effects of unilateral and bilateral lesions of the telencephalotectal fibres of the Tractus occipitomesencephalicus (OM) were studied in pigeons in a successive visual pattern discrimination.
Electrolytic lesions were placed in the tractus septomesencephalicus (TSM) and Tractus occipitomesencephalicus (TOM), efferent pathways originating in visual and somatosensorimotor areas of the avian telencephalon and distributing widely to brain stem and spinal nuclear regions.
Lesions of the anterior-intermedium archistriatum or interruption of its descending projection (Tractus occipitomesencephalicus) had no effect on conditioned response development. In contrast, destruction of the posterior-mediale region or interruption of its descending projection (Tractus occipitomesencephalicus, pars hypothalami) produced profound conditioning deficits. It is concluded that the integrity of the posterior-mediale region and its projection to the hypothalamus via the Tractus occipitomesencephalicus, pars hypothalami are essential for establishing visually conditioned heart rate change in a defensive conditioning paradigm, and these findings are discussed in the context of structures previously implicated in mediating this conditioning autonomic response..
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