Canary pox in sparrows and canaries (Fringillidae and in weavers (Ploceidae). Pathology and host specificity of the virus.
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A sexual difference in vasotocin (VT) immunoreactivity was observed in the canary brain. The male canary displays denser VT innervation of the lateral septum and more VT-immunoreactive cells are visible in the dorsal diencephalon than in the female canary. This sex difference is the consequence of gonadal influences. Castration of male canaries resulted in a substantial decrease of VT immunoreactivity in these septal and diencephalic cells and fibers. Testosterone administration to castrated males restored the original intensity of fiber and cell staining. Testosterone treatment of female canaries induced strong VT immunostaining in the above regions similar to that in the male canary.
A male canary from the Belgian Waterslager strain, which is known for its elevated high-frequency thresholds and a female of German Roller canary with normal high-frequency thresholds were bred. Operant techniques and a psychophysical tracking procedure were used to measure auditory sensitivity of six F1 hybrid canaries from this cross. Three patterns of auditory sensitivity were observed in the six hybrid birds. Four birds showed elevated high-frequency hearing characteristic of the Belgian Waterslager strain; one bird showed normal hearing, and one bird showed an intermediate pattern of auditory sensitivity. A spectral analysis of contact calls recorded from these F1 hybrid canaries showed a spectral distribution of energy which was intermediate between that of Belgian Waterslager strain and the German Roller strain. These results suggest there may be a relation between hearing sensitivity and the spectral distribution of energy in the calls of domestic canaries. Such hybrids may prove useful for examining the genetic basis of more complex behaviors such as vocal learning.
In 212 sera from budgerigar and canary fanciers with symptoms of rhinitis and/or bronchial asthma, IgE antibodies against budgerigar feathers (Budf) or canary feathers (Canf) were determined. In 25 of 98 Canf-specific IgE antibody measurements, and in 28 of 154 Budf-specific IgE antibody measurements, a significant (6% or more binding of 125I-anti-IgE) level of specific IgE was found. In 3 sera with the highest levels of Canf- or Budf-specific IgE, IgE antibodies against sera from both birds were present. It is concluded that IgE antibodies against canary and/or budgerigar feathers are present in about 20% of canary and budgerigar fanciers with symptoms of atopic disease. Canary and budgerigar feathers contain IgE-binding antigens that are not present in the corresponding bird sera and droppings.
We found that the canary N-myc gene is highly related to mammalian N-myc genes in both the protein-coding region and the long 3' untranslated region. Examined coding regions of the canary c-myc gene were also highly related to their mammalian counterparts, but in contrast to N-myc, the canary and mammalian c-myc genes were quite divergent in their 3' untranslated regions. We readily detected N-myc and c-myc expression in the adult canary brain and found N-myc expression both at sites of proliferating neuronal precursors and in mature neurons.
Cowbirds (Molothrus ater) and grackles (Cassidix mexicanus) infected with muscle cysts of Sarcocystis were fed to opposums (Didelphis virginiana) and fecal sporocysts from the latter were given to sparrows (Passer domesticus, Family Ploceidae), canaries (Serinus canarius, Family Fringillidae) and ducks (Anas platyrhynchos, Family Anatidae). Asexual parasites were found in the endothelium of sparrows and canaries but not in ducks. When birds were kept 10 weeks or more after infection, muscle cysts were found grossly and microscopically in the majority of sparrows, and in 1 canary, but not in ducks. Muscle zoites were found in digests of all sparrows and canaries but not in that of ducks. Metrocytes and forms dividing by endodyogeny also were found in the digest. Thus, avian Sarcocystis was transmitted experimentally from 2 genera of 1 family (Icteridae) to 2 different families of passerine intermediate hosts by sporocysts from the definitive host. This is the broadest intermediate host spectrum known for a species of Sarcocystis.
We have traced central nervous pathways controlling bird song in the canary using a combination of behavioral and anatomical techniques. Unilateral electrolytic brain lesions were made in adult male canaries whose song had been previously recorded and analysed on a sound spectrograph. After several days of postoperative recording, the birds were sacrificed and their brains processed histologically for degeneration staining with the Fink-Heimer technique. Although large lesions in the neostriatum and rostral hyperstriatum had no effect on song, severe song deficits followed damage to a discrete large-celled area in the caudal hyperstriatum ventrale (HVc). Degenerating fibers were traced from this region to two other discrete nuclei in the forebrain: one in the parolfactory lobe (area X, a teardrop-shaped small-celled nucleus); and a round large-celled nucleus in the archistriatum (RA). Unilateral lesion of X had no effect on song; lesions of RA, however, caused severe song deficits. Degenerating fibers from RA joined the occipitomesencephalic tract and had widespread ipsilateral projections to the thalamus, nucleus intercollicularis of the midbrain, reticular formation, and medulla. It is of particular interest that direct connections were found onto the cells of the motor nucleus innervating the syrinx, the organ of song production. Unilateral lesions of n. intercollicularis (previously implicated in the control of vocal behavior) had little effect on song. One bilateral lesion of HVc resulted in permanent (9 months) and complete elimination of the audible components of song, although the bird assumed the posture and movements typical of song. Preliminary data suggest that lesions of the left hemisphere result in greater deficits than lesions of the right one. This finding is consistent with earlier reports that the left syrinx controls the majority of song components. Results reported here suggest a localization of vocal control in the canary brain with an overlying left hemispheric dominance.
Groups of juvenile and 1-year-old male canaries were treated briefly with the vasotocin (VT) analog desGly(NH2)9d(CH2)5-[Tyr(Me)2,Thr4, Orn8]VT (dGVTA) during four time intervals between September and February. The canaries received subcutaneously testosterone-containing silastic implants at the start of the VT analog treatment to assure that despite age and season differences the birds would all have comparable plasma levels of testosterone. The VT analog was administered subcutaneously (0.7 micrograms/100 microliters) during the first 3 days (3 injections daily) of chronic testosterone treatment. Observations on the singing behavior were carried out between Day 8 and Day 30 after implantation of the testosterone-filled silastic tubing. The short-term administration of the VT analog influenced the amount of singing behavior during a 30-min observation interval measured 1 to 4 weeks later. Despite age differences the effect of dGVTA held and seemed more related to season than to age. The song duration (seconds of song/30 min) was affected in a dual mode. In early autumn the VT analog enhanced song duration of testosterone-primed canaries, but the same VT analog decreased song duration in the period November/January. These results suggest that the neuropeptide VT is implicated in control of seasonal changes in singing behavior.
Young male canaries become sexually mature in late winter, 8-12 months after hatching. During the months between hatching and sexual maturity they develop adult song. The successive stages in the development of adult song are subsong, plastic song, and stable or full song. Once stable song is achieved it lasts for the duration of the breeding season. After the end of the breeding season there is a recurrence of song instability during summer and early fall. This plastic song is followed, once more, by stable song. New song syllables are added to the song of adult male canaries and some of the earlier syllables disappear. The song repertoire sung at 2 years of age is substantially larger, and different, from that sung during the first breeding season, when the birds were 1 year old. A comparable change occurs between the second and third breeding seasons. Most of the syllables acquired by adult males are formed during the summer-fall period of song instability. Developmental and seasonal changes in song are accompanied by anatomical changes in two forebrain nuclei known to be involved in song control, the hyperstriatum ventralis, pars caudalis (HVc), and the robust nucleus of the archistriatum (RA). HVc and RA grow during the subsong and plastic song periods of song development. These nuclei reach adult size by the time stable adult song is first produced, and retain this size during the breeding season. However, the size of HVc and RA diminishes by late summer, when it becomes comparable to that of a 3- to 4-month-old bird. This reduction in size is temporary and has been corrected by the following breeding season. It is suggested that these seasonal changes in volume reflect circuit changes which are under hormonal control, and that these changes are related to processes of learning and, possibly, forgetting. Despite earlier reports of left hemispheric dominance in canary song production, we failed to find any evidence of right-left systematic differences in the size of HVc and RA during development or in adulthood. Various hypotheses relating song learning to changes in the underlying anatomy are offered.
The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization.
As in other songbirds, early deafening had drastic effects on the song of the roller canary, a cardueline finch, resulting in a song that was much simpler and more variable than the normal. The repertoire of the syllable types, of which the song is made, was reduced from 30 to a mean of 5.0. Loud white noise was successfully used as a reversible method of cutting off auditory feedback from vocal behavior. Although suffering permanent elevation of hearing thresholds, birds reared in noise to 200 days, singing at first like deaf birds, subsequently increased their syllable repertoires significantly. Birds reared in noise to weaning at 40 days, again partly deaf, achieved a normal repertoire size when stimulated with a singing adult. Without such stimulation the repertoire was significantly reduced, showing that canary song is not fully innate, as had been thought. Although abnormal, the song of deaf canaries retained more species-specific features than did the song of emberizine sparrows when the songs developed without auditory feedback. The results are interpreted in terms of a sensory template theory.
Adult canaries (Serinus canarius) from a closebred colony of the Belgian "Waterslager" strain were trained with operant techniques to respond to pure tones. A psychophysical tracking procedure was used to measure absolute auditory thresholds in quiet and in noise. Absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB higher (4-5 standard deviations) than those typically reported for other song birds including canaries of other strains and Waterslagers tested some years ago from another colony. Thus the Millbrook colony of domestic canary--an oscine songbird which learns its vocalizations by reference to auditory information--shows unusually high absolute thresholds for pure tones.
Canaries (Serinus canarius) of the Belgian waterslager strain from two different colonies were trained with operant techniques for audiometric testing. For both young and old birds, absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB (SPL) higher than those of other song birds, including canaries of other strains. Thus the Belgian waterslager canary, selectively bred for loud, low-pitched song, has also developed poor high-frequency hearing.
Canaries and other songbirds offer unique advantages for analyzing the relationship between specific gene regulation and neural plasticity. To establish a quantitative profile of the population of RNAs potentially involved in this regulation, we analyzed the solution hybridization kinetics of canary forebrain cytoplasmic polyadenylated RNA. Hybridization of forebrain cDNA to forebrain RNA provides evidence for RNA species at individual concentrations ranging from less than 10(-6) to about 10(-3) (by fractional mass). Cross-hybridization to RNA from the rest of the brain, together with other studies, defines a subpopulation of about 5000 rare RNAs that are enriched in the forebrain compared to the rest of the brain. Some of these forebrain-enriched RNAs are likely to play a role in regulating the neural plasticity characteristic of the canary forebrain.
We present in this paper a report of 155 species used for medicinal purpose in the Canary Islands. These species have been compiled in 13 tables in accordance with their main medicinal use, indicating also other possible popular uses. We have made a short inventory of the rates of the most important medicinal applications. This new compilation shows once more the traditional use of the phytotherapeutic resources by the Canary population and also the wide possibilities of the phytochemical and pharmacological investigations of the Canary Islands Flora.
Thymidine autoradiography and retrograde transport of horseradish peroxidase (HRP) were combined to determine the connectivity of neurons born in adult canary forebrain. Adult male and female canaries were pretreated with [3H]thymidine to label cells undergoing DNA synthesis prior to mitosis. Thirty or 60 days later, neurons in a forebrain nucleus, hyperstriatium ventralis, pars caudalis (HVc), were labeled by retrograde transport of HRP injected into the only two nuclei known to receive a projection from HVc: robustus archistriatalis (RA) and area X of lobus parolfactorius. The birds were then killed and brain sections were treated to visualize cells containing HRP; these sections were processed for autoradiography to detect [3H]thymidine-labeled cells in the same tissue. More than 9% of all neurons in HVc were thymidine labeled; but of the almost 20,000 HRP-labeled projection neurons examined, fewer than 20 (0.1%) were labeled by the thymidine treatment. Furthermore, the median cell body size for area X-projecting cells was significantly larger than that of thymidine-labeled cells, and the median size of thymidine-labeled cells was significantly larger than that of RA-projecting cells. The simplest interpretation of these results is that the new neurons incorporated into nucleus HVc in adult canary brain are local interneurons, intermediate in size between neurons projecting to RA and area X.
Anterograde projections of a telencephalic auditory area - field L of the neostriatum - were traced in canaries, Serinus canarius. Field L was defined as the neostriatal projection of nucleus ovoidalis of the thalamus. Using amino acid autoradiography, two efferent projections of field L and adjacent neostriatum were observed: (1) a projection to the medial and ventral borders of nucleus hyperstriatum ventrale, pars caudale (HVc) and (2) a smaller projection to medial paleostriatum augmentatum (PA). When autoradiographic injection sites included neostriatum postero-ventral to field L, a projection to archistriatum outlining the anterior and ventral borders of the nucleus robustus archistriatalis (RA) resulted. Injection sites that included neostriatum antero-lateral to "L" gave rise to projections to the interior of HVc proper. Above background numbers of silver grains were consistently observed over caudal dorso-lateral portions of nucleus ovoidalis. Following lesion of field L and adjacent neostriatum, argyrophilic degeneration was traced to medial PA and to a shelf of neostriatum underlying HVc. All observed anterograde projections were ipsilateral. Two of the nuclei outlined by neostriatal projections in this study, HVc and RA, have important roles in the motor control of canary song (Nottebohm et al., '76). The development of song is dependent on auditory information. Auditory-vocal neural connections described here may be involved in song learning.