Hans-Joachim Bischof

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BACKGROUND The Radical-Pair-Model postulates that the reception of magnetic compass directions in birds is based on spin-chemical reactions in specialized photopigments in the eye, with cryptochromes discussed as candidate molecules. But so far, the exact subcellular characterization of these molecules in the retina remained unknown. METHODOLOGY/PRINCIPAL(More)
Neuroanatomical studies including pathway tracing and cytochemical characterizations have suggested that the avian nucleus taeniae of the amygdala (TnA) might be homologous to a part of the mammalian medial amygdala. Recent behavioral observations in TnA-lesioned birds also reported deficits in the control of motivational aspects of behavior, advancing the(More)
Although the ability to use the Earth's magnetic field for long distance orientation and navigation has been demonstrated in many animals, the search for the appropriate receptor has not yet finished. It is also not entirely clear whether the use of magnetic field information is restricted to specialists like migrating birds, or whether it is a sense that(More)
A caudal forebrain area of zebra finches that comprises a part of the caudal nidopallium and a part of the intermediate arcopallium is highly activated during courtship. This activation is thought to reflect the processing of information that is necessary for the choice of an appropriate mate. In addition to the information on the potential mate, control of(More)
Club-shaped Hairs in the Cerci of the Cricket Gryllus bimaculatus Acting as Gravity Receptors Summary. 1. The club-shaped hairs are innervated by one sensory cell with phasic-tonic properties. The largest changes of spike frequency are produced by deflection of the hairs along their preferential plane. The smallest deflection that will induce changes of the(More)
Sexual imprinting is an early learning process by which young birds acquire the characteristics of a potential sexual partner. The physiological basis of this learning process is an irreversible reduction of dendritic spines in two forebrain areas, the LNM (lateral nido-mesopallium) and the MNM (medial nido-mesopallium). The aim of the present study was to(More)
In the cricket, Gryllus bimacuIatus, compensatory head movements are elicited by cereal and antennal receptors when the animals are rotated around their longitudinal axis. The cereal afferences originate in the club-shaped sensilla, whereas the antennal ones probably arise in receptors measuring displacements of the flagellum at the joint between scapus and(More)
The avian nucleus taeniae of the amygdala (TnA) corresponds to part of the mammalian medial amygdala. Like its mammalian counterpart, it has been shown to be involved in the control of social function. According to behavioral observations, such control is already necessary early in the ontogenetic development of a bird. If so, TnA should be one of the(More)
Sexual imprinting occurs in two stages, an acquisition phase when the birds learn about their social environment, and a consolidation process where the acquired information is linked to sexual behaviour and stabilized. Some of the factors that may influence acquisition and consolidation, respectively, were examined. Zebra finch, Taeniopygia guttata, males(More)
We tested the role of the hippocampus in spatial memory of zebra finches. The birds were trained to find the location of a food site among four identical feeders arranged on the aviary floor. Extra-maze cues were present. The birds had to perform the task from four different starting points. Successful visits and the time to find the food were recorded.(More)