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Biomedical subjects

J D Delius

Publications and source records attributed to J D Delius.

52 records · Page 3Linked to original sources
PubMed1976

Adrenocorticotropic hormone, glucose and displacement activities in pigeons.

The possibility that displacement activities might be consequences of stress-induced humoral responses was investigated. Adrenocorticotropic hormone and glucose were injected into the brain ventricles of unrestrained domestic pigeons. ACTH leads to an increased frequency of yawning and headshaking and glucose to a decrease in arousal. It is concluded that these behavioural responses correspond partly with the displacement activities shown by birds. The role of the cerebrospinal fluid as a mediator of behaviourally active substances is discussed.

Adrenocorticotropic Hormone↗
PubMed1976

Vestibular projections to the thalamus of the pigeon.

Microelectrode recording in the thalamus of pigeons subjected to tilt and sinusoidal rotational stimuli around the vertical, longitudinal and transversal axes revealed vestibularly driven units in two thalamic nuclei, the nucleus posteroventralis and the nucleus principalis precommissuralis. Many of these units responded in a complex manner suggesting that inputs from contralateral and ipsilateral cupulae and maculae converged on them. A few units received additional visual or proprioceptive information. The homology relationship with a mammalian vestibular thalamic nucleus is discussed briefly.

Action Potentials↗
PubMed1974

Stimulus control of heart rate by auditory frequency and auditory pattern in pigeons.

A new method was used to investigate auditory discrimination in pigeons. Basically, the method involves the repeated presentation of one stimulus preceding the single presentation of a different stimulus that is followed by shock. Stimulus control is assessed by the increase in heart rate that accompanies the presentation of the second stimulus. In Experiment 1, the efficiency of the method was explored by determining the frequency difference thresholds of pigeons at 500, 1000, 2000, and 4000 Hz. Weber fractions comparable to those reported in an earlier study using the conditioned suppression method were obtained. Experiment 2 demonstrated that, contrary to results of earlier studies, auditory temporal patterns can exercise differential stimulus control in pigeons. One stimulus consisted of the presentation (once per second) of a 1000-Hz pure tone of 150 msec duration followed by a 2000-Hz pure tone of equal duration; the other was the same except for the reversed order of the frequency components. Results indicated that the frequency pattern and not the loudness pattern of the stimuli was the cue controlling heart-rate changes.

Acoustic Stimulation↗
PubMedDate not supplied

Frontal forebrain lesions: effects on the foraging and apomorphine pecking of pigeons.

The role of the nucleus basalis prosencephali (Bas), a frontal forebrain structure peculiar to birds, in the control of forage pecking and apomorphine-induced pecking was investigated. In a quasi-natural grit-grain selection task bilateral coagulations of the Bas and the associated neostratum frontolaterale (Nfl) caused a marked fall in grain per peck uptake and a simultaneous increase in grit per peck uptake. Bas lesions also had a reducing effect on the compulsive pecking elicited by systemic injections of apomorphine. This confirms that the Bas is involved in the control of forage pecking and dopaminergic pecking of birds.

Animals↗