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PubMedDate not supplied

Contact call-driven Zenk protein induction and habituation in telencephalic auditory pathways in the Budgerigar (Melopsittacus undulatus): implications for understanding vocal learning processes.

Expression of the immediate early gene protein Zenk (zif 268, egr-1, NGF1A, Krox24) was induced in forebrain auditory nuclei in a vocal learning parrot species, the budgerigar (Melopsittacus undulatus), when the subjects either listened to playbacks of an unfamiliar contact call or to a contact call with which they had been familiarized previously. Auditory nuclei included the Field L complex (L1, L2a, and L3), the neostriatum intermedium pars ventrolateralis (NIVL), the neostriatum adjacent to caudal nucleus basalis (peri-basalis or pBas), an area in the frontal lateral neostriatum (NFl), the supracentral nucleus of the lateral neostriatum (NLs), and the ventromedial hyperstriatum ventrale (HVvm). The latter three nuclei are main sources of auditory input to the vocal system. Two patterns of nuclear staining were induced by contact call stimulation-staining throughout cell nuclei, which was exhibited by at least some neurons in all areas examined except L2a and perinucleolar staining, which was the only kind of staining exhibited in field L2a. The different patterns of Zenk staining indicate that auditory stimulation may regulate the Zenk-dependent transcription of different subsets of genes in different auditory nuclei. The numbers of neurons expressing Zenk staining increased from seven- to 43-fold over control levels when the birds listened to a repeating unfamiliar call. Familiarization of the subjects with the call stimulus, through repeated playbacks, greatly reduced the induction of Zenk expression to the call when it was presented again after an intervening 24-h interval. To determine if neurons exhibiting contact call-driven Zenk expression project to the vocal control system, call stimulation was coupled with dextran amines pathway tracing. The results indicated that tracer injections in the vocal nucleus HVo (oval nucleus of the hyperstriatum ventrale), in fields lateral to HVo and in NLs labeled many Zenk-positive neurons in HVvm, NFl, and NLs. These results support the idea that, in these neurons, egr-1 couples auditory stimulation to the synthesis of proteins involved in either the storing of new perceptual engrams for vocal learning or the processing of novel and/or meaningful acoustic stimuli related to vocal learning or the context in which it occurs.

Animal Communication↗
PubMed1997

Vimentin- and desmin-positive cells in the moulting budgerigar (Melopsittacus undulatus) skin.

The distribution of vimentin- and desmin-positive cells in the budgerigar (Melopsittacus undulatus) dermis was investigated by means of immunohistochemical reactivity with the commercially available (Euro-Diagnostics) polyclonal antibodies. The staining pattern for vimentin in the paraffin sections was generally comparable to that in other animal species with regard to endothelial cells, vascular wall cells, muscle cells and fibroblasts. The modified Schwann cells in the inner core of the Herbst corpuscles reacted distinctly with anti-vimentin and anti-desmin. Some connective tissue cells in the superficial dermal layer, in the feather papilla and along the pulp core inside of the regenerating feathers were particularly well stained with anti-vimentin. Fibroblast-like cells of the regenerating feathers, particularly at the base of the pulp, also reacted strongly with anti-desmin. The findings were discussed with regard to references.

Animals↗
PubMedDate not supplied

Pathogenesis of Sarcocystis falcatula (Apicomplexa: Sarcocystidae) in the budgerigar (Melopsittacus undulatus). IV. Ultrastructure of developing, mature and degenerating sarcocysts.

Sarcocysts in cardiac and skeletal muscles of budgerigars (Melopsittacus undulatus) were examined transmission electron microscopically 5 to 168 days after experimental infection with Sarcocystis falcatula. The ultrastructure of the primary cyst wall, amorphous substance, metrocytes and bradyzoites in developing, degenerating and mature sarcocysts is described and compared with precystic merozoites studied previously. Sufficient morphologic differences between precystic merozoites, metrocytes and bradyzoites (cystozoites) were found which seem to justify their semantic differentiation. Significant differences in immature and mature primary cyst wall morphology were encountered. If primary cyst wall morphology is to be used in determination and differentiation of species of Sarcocystis, then caution must be used to employ only mature sarcocysts.

Animals↗
PubMed1983

[Retention of indoles in the pineal organ of the bird (Melopsittacus undulatus, Shaw) during its preparation for radioautographic study].

Since high-resolution radioautography (dipping technique) might be very useful for the study of indole metabolism in the pineal cells, the retention of [3H]-indoles has to be examined during the preparation of specimens for electron microscopy (EM). The pineal organ of the parakeet (Melopsittacus undulatus) was used in the present work. 1) Indole metabolism: following uptake of [3H]-5-hydroxytryptophan ([3H]-HW) in vivo and [3H]-5-hydroxytryptamine ([3H]-HT) in vitro in similar seasonal and nycthemeral conditions--all the known pineal indolic metabolites were recovered by thin layer chromatography. [3H]-5-methoxyindoles were also formed from [3H]-melatonin ([3H]-aMT). 2) The radioactivity of fluids used in the processing of pineal organs in EM was determined by liquid scintillation counting: (a) no exogenous [3H]-indoles could be revealed in EM solutions after [3H]-HW in vivo uptake. (b) 8.8 to 13.4% of [3H]-indoles were washed out by glutaraldehyde after [3H]-HT in vitro uptake. (c) most of the 5-methoxyindoles after in vitro uptake of [3H]-aMT were lost in glutaraldehyde. Our chromatography procedures did not permit the identification of [3H]-indoles extracted by the glutaraldehyde fixative. In previous experiments, [3H]-HW and [3H]-HT uptake showed the presence of selective radioautographic reactions in the cells of the receptor line; however, silver grains were scarce and diffusely distributed in the pineal parenchyma after [3H]-aMT uptake.

5-Hydroxytryptophan↗
PubMed2002

Auditory brainstem responses in adult budgerigars (Melopsittacus undulatus).

The auditory brainstem response (ABR) was recorded in adult budgerigars (Melopsittacus undulatus) in response to clicks and tones. The typical budgerigar ABR waveform showed two prominent peaks occurring within 4 ms of the stimulus onset. As sound-pressure levels increased, ABR peak latency decreased, and peak amplitude increased for all waves while interwave interval remained relatively constant. While ABR thresholds were about 30 dB higher than behavioral thresholds, the shape of the budgerigar audiogram derived from the ABR closely paralleled that of the behavioral audiogram. Based on the ABR, budgerigars hear best between 1000 and 5700 Hz with best sensitivity at 2860 Hz-the frequency corresponding to the peak frequency in budgerigar vocalizations. The latency of ABR peaks increased and amplitude decreased with increasing repetition rate. This rate-dependent latency increase is greater for wave 2 as indicated by the latency increase in the interwave interval. Generally, changes in the ABR to stimulation intensity, frequency, and repetition rate are comparable to what has been found in other vertebrates.

Acoustic Stimulation↗
PubMed1985

Temporal integration of acoustic signals by the budgerigar (Melopsittacus undulatus).

Avoidance conditioning and a modified method of limits psychophysical procedure were used to study temporal integration of tone and noise signals in the budgerigar (Melopsittacus undulatus). Integration of both tone and noise signals can be described by a negative exponential function with a time constant of about 200 ms. At very short durations there were differences in the integration of tone and noise signals. These data are similar to those reported for a number of other vertebrates, including man. Thresholds for two complex natural vocalizations of the budgerigar are similar to those of pure tones of equivalent duration.

Animals↗
PubMed1997

Mechanisms of vocal production in budgerigars (Melopsittacus undulatus).

Songbirds vocalizing in helium show a change in the spectral quality of their vocalizations. This effect is due to an increase in the speed of sound in helium that in turn alters the resonance properties of the vocal tract. Here, this approach is extended to a psittacine, the budgerigar (Melopsittacus undulatus), whose syringeal anatomy and innervation differ from that of a songbird. Contact calls from birds vocalizing in heliox (70/30 helium/oxygen environment) showed an overall increase in the amount of energy at frequencies above the fundamental, slight changes in the frequency of the fundamental and harmonics, and some change in the level of harmonics. Calls produced by a syringeally denervated bird showed more dramatic changes. Recordings from live birds were compared with sounds produced by various simple "artificial" tracheal and syringeal models. Results suggest that budgerigars produce contact calls using the syringeal membranes as a unitary sound source which produces acoustic energy in a narrow frequency band whose fundamental frequency is matched to the resonant frequency of the trachea. The syrinx is not normally coupled to the tracheal resonator, and resonances probably play only a minor role in shaping the spectrum of contact calls.

Acoustics↗
PubMed1997

Perception of synthetic /ba/-/wa/ speech continuum by budgerigars (Melopsittacus undulatus).

Other than humans, extensive vocal learning has only been widely demonstrated in birds. Moreover, there are only a handful of avian species that are known to be good mimics of human speech. One such species is the budgerigar (Melopsittacus undulatus), which is a popular mimic of human speech and learns new vocalizations throughout adult life. Using operant conditioning procedures with a repeating background task, we tested budgerigars on the discrimination of tokens from two synthetic /ba/-/wa/ speech continua that differed in syllable, but not transition, duration. Budgerigars showed a significant improvement in discrimination performance on both continua near the phonetic boundary for humans. Budgerigars also showed a shift in the location of the phonetic boundary with a change in syllable length, similar to what has been described for humans and other primates. These results on a nonmammalian species provide support for the operation of a general, nonphonetic, auditory process as one mechanism which can lead to the well-known stimulus-length effect in humans.

Adult↗
PubMed1999

Vocal production mechanisms in the budgerigar (Melopsittacus undulatus): the presence and implications of amplitude modulation.

In this paper acoustic evidence is presented for the presence of amplitude modulation in budgerigar (Melopsittacus undulatus) contact calls and learned English vocalizations. Previously, acoustic analyses of budgerigar vocalizations have consisted solely of visual inspection of spectrograms or power spectra (derived from Fourier transformation). Such analyses have led researchers to conclude that budgerigar vocalizations are primarily frequency-modulated, harmonic vocalizations. Although budgerigar calls have been shown to contain regions that are modulated in amplitude, the implications of this fact have been largely ignored. Amplitude modulation, the nonlinear interaction between two separate signals that results in the creation of new, heterodyne (sum and difference) frequencies, can produce a very complex Fourier spectrum that may resemble that produced by a harmonic vocalization. In this paper, the acoustic principles necessary for identifying amplitude modulation present in signals are outlined, and followed by data demonstrating that amplitude modulation is a prominent feature not only of natural budgerigar contact calls, but also of their learned English vocalizations. It is illustrated how analyzing a vocalization that contains amplitude modulation as if it were harmonic can result in misinterpretations of the acoustic and physical properties of the sound and sound source. The implications of amplitude modulation for studies of the ontogenetic, physical, and neural basis of budgerigar vocalizations are discussed, and a potential model for how the budgerigar syrinx may function to produce amplitude modulation is proposed.

Animals↗
PubMed2000

Frequency discrimination in budgerigars (Melopsittacus undulatus): effects of tone duration and tonal context.

Studies of frequency resolving power in budgerigars (Melopsittacus undulatus) have shown that this species has excellent discrimination abilities for both simple and complex sounds falling in the region of 2 to 4 kHz--the frequency range of their contact call. In four experiments, frequency discrimination by budgerigars of short tones similar to elements found in the contact call was examined. Frequency difference limens (FDLs) for simple pure tones at 2.86 kHz were constant for tone durations above 20 ms but higher for shorter tones. Budgerigars generally showed larger FDLs for shorter duration 1-, 2-, and 4-kHz pure tones. FDLs in budgerigars for 20-ms tones embedded in a sequence of six other tones were similar to FDLs measured for tones of the same frequency presented in isolation. Moreover, there was no effect of introducing trial-by-trial variation in the location of the frequency change in the seven-tone complexes for budgerigars, a condition for which humans showed a large decrement in performance. Taken together, these results suggest budgerigars possess enhanced spectral resolving power for short duration pure tones when they are embedded in contact call-like tonal patterns.

Animals↗
PubMed1980

A survey of causes of mortality in budgerigars (Melopsittacus undulatus).

Lesions found in 257 post mortem examinations of budgerigars (Melopsittacus undulatus) are recorded. The commonest disease was neoplasia, principally of the gonads, kidneys and fat. Hepatitis and focal hepatic necrosis, thyroid dysplasias and septicaemias were also common. A great variety of other disease processes occurred; each affected only a few birds.

Animals↗
PubMed2001

Calcitonin gene-related peptide immunoreactive cells and fibers in forebrain vocal and auditory nuclei of the budgerigar (Melopsittacus undulatus).

The distributions of calcitonin gene-related peptide (CGRP) immunoreactive neurons and fibers were mapped within forebrain vocal control and auditory nuclei of a vocal learning psittacine species, the budgerigar (Melopsittacus undulatus). Immunoreactivity was exhibited by telencephalic nuclei previously associated with vocal control pathways on the basis of both tract tracing studies and gene mapping: the central nucleus of the anterior archistriatum (AAc), central nucleus of the lateral neostriatum (NLc), magnocellular nucleus the lobus parolfactorius (LPOm), the oval nucleus of the ventral hyperstiratum (HVo) and the medial division of the oval nucleus of the anterior neostriatum (NAom). The main body of NAo also contained an exceptionally high density of immunoreactive fibers. In contrast to the condition in oscine songbirds, CGRP-positive neuronal somata were not present in any telencephalic vocal control nucleus. CGRP-positive somata were present, however, in diencephalic cell groups that included the shell region of the nucleus ovoidalis (Ov), the nucleus dorsolateralis posterior (DLP) and a region of the ventral thalamus that was retrogradely labeled by tracer deposits into HVo and AAc. CGRP immunoreactive fibers were observed within auditory areas of the telencephalon including Field L and the neostriatum intermedium pars dorsolateralis. The likely sources of these fibers are CGRP-positive neurons within the Ov shell and DLP.

Animals↗
PubMed1993

Auditory projections to the anterior telencephalon in the budgerigar (Melopsittacus undulatus).

The connections of a higher order auditory area in the neostriatum intermedium pars ventrolateralis (NIVL) were mapped with pathway tracing techniques in order to elucidate possible pathways by which auditory feedback may influence vocal learning in the budgerigar (Melopsittacus undulatus). Previous research has shown that NIVL receives projections from Field 'L' as well as adjacent portions of the dorsolateral neostriatum intermedium (NIDL) and hyperstriatum ventrale (HV) and, therefore, may be homologous to previously described auditory centers in the dorsal and lateral portions of the auditory neostriatum of songbirds. The efferent connections of NIVL terminate within a small portion of the rostromedial archistriatum as well as a more rostrally situated area within the medial neostriatum intermedium (NI) and HV. Near by (but not overlapping) fields in NI and HV receive input from the nucleus dorsomedialis posterior thalami (DMP), the archistriatum and ectostriatum. Interestingly, only the DMP projection field overlaps a neural field known to be related to the vocal motor system. The DMP projection field corresponds to that previously described as the magnocellular nucleus of the anterior neostriatum; this nucleus is known to project to the higher vocal center in the budgerigar. In addition to projections from NIVL to medial NI and HIV, auditory information is relayed to the anterolateral telencephalon directly from the brainstem via the ventrolateral nucleus of the lateral lemniscus (VLV). This latter pathway appears comparable to that described in pigeons derived from the intermediate nucleus of the lateral lemniscus. The projection field of VLV overlaps a restricted portion of the caudal and medial aspect of nucleus basalis. These results support the notion that many aspects of telencephalic auditory pathways in birds are primitive characters, although a direct connection between auditory and vocal motor circuits was not found in the present study.

Animals↗
PubMed1986

Interordinal conservatism of chromosome banding patterns in Gallus domesticus (Galliformes) and Melopsittacus undulatus (Psittaciformes).

Chromosome banding homologies were studied between the domestic chicken, Gallus domesticus (Galliformes), and the budgerigar, Melopsittacus undulatus (Psittaciformes). In spite of large karyological differences, the G-banding patterns were found to be conserved to a considerable extent between the two species. There were some differences in C- and Hoechst 33258/Q-banding patterns.

Animals↗
PubMed1997

Encephalitozoon hellem in budgerigars (Melopsittacus undulatus).

Microsporidiosis with concurrent megabacteriosis in budgerigar (Melopsittacus undulatus) chicks contributed to significant economic floss in a commercial pet bird aviary in Mississippi. Three budgerigar chicks, 1-2 weeks old, from the aviary were necropsied. Microscopic lesions in the chicks consisted of heavy infection of enterocytes with microsporidia (2/3; autolysis precluded critical evaluation of the intestine of chick No. 2), multifocal hepatic necrosis and inflammation with intralesional microsporidia (1/3), spherical clusters of microsporidia in the hepatic sinusoids in the absence of inflammation (1/3), and gastric megabacteriosis (3/3). The ultrastructure of the microsporidian spores was consistent with an Encephalitozoon species. The polymerase chain reaction and Southern blot analysis were used to identify the microsporidian as Encephalitozoon hellem, an organism that has only been identified in humans. Encephalitozoon hellem causes keratoconjunctivitis and respiratory infections in humans with acquired immunodeficiency syndrome. This report presents the first confirmed case of microsporidiosis in budgerigars. The finding of E. hellem in pet birds may be important in elucidating the epidemiology of human infections with this organism.

Animals↗
PubMed1994

NEUROMUSCULAR CONTROL AND KINEMATICS OF INTERMITTENT FLIGHT IN BUDGERIGARS (MELOPSITTACUS UNDULATUS)

Kinematic and electromyographic data were collected from budgerigars (parakeets), Melopsittacus undulatus, flying at different speeds in a variable-speed wind tunnel. Birds exhibited flap-gliding at low speeds and flap-bounding at high speeds. The percentage of time spent flapping generally decreased at intermediate speeds. These behavior patterns are consistent with minimizing energy expenditure according to aerodynamic theory. During intermittent glides, the pectoralis exhibited an isometric contraction while the supracoracoideus was inactive. During bounds, both muscles were inactive. Contrary to earlier work, our studies indicate that budgerigars do not exhibit simultaneous twitch contractions of the pectoralis during each wingbeat, but rather generate typical multiple-spike electromyographic bursts that represent motor unit action potential trains or asynchronous twitch contractions from different motor units. The relative intensity of electromyographic bursts from the primary flight muscles increased with flight speed. This may indicate an increase in force production. Our observations of isometric contractions during glides, along with patterns of variation in muscle activity and wingbeat frequency, do not support the hypothesis that small birds such as the budgerigar use flap-bounding as their only means of reducing power output during flight.

Journal Article↗
PubMed1998

Endogenous amino acids in budgerigars (Melopsittacus undulatus).

To determine the amount of endogenous amino acids in budgerigars (sekiseiinko, Melopsittacus undulatus), as the first step of evaluating amino acid requirements, three experiments were conducted. In Experiments 1 and 2, transit time of the feeds through the digestive tract in budgerigars was studied. The birds were given free access to a corn-based diet containing 50% barium sulfate in Experiment 1, and Japanese millets (hie, Echinochloa utilis) with 0.5 ml of 50% barium sulfate solution in Experiment 2. At intervals of 0.5 to 2 hr, roentgenography was conducted to identify the position of the barium sulfate in the digestive tract. The results showed that the transit time of pellets and millets in the digestive tract was within 24 and 27 hr, respectively. In Experiment 3, to determine the amount of endogenous amino acids in budgerigars, the excreta were collected for 24 hr, from 27 to 51 hr after fasting. The excreta were hydrolyzed with 6 N hydrochloric acid at 110 degrees C for 22 hr for the determination of amino acids by HPLC. The endogenous Ala, Arg, Leu, Lys, Phe and Val were estimated to be 34.9, 36.8, 18.5, 20.3, 15.3 and 18.9 micrograms/day/BW0.75, respectively, which were higher than those in adult roosters.

Amino Acids↗
PubMed2004

Variation in the behavioral responses of Budgerigars Melopsittacus undulatus to an alarm call in relation to sex and season.

In the Budgerigar Melopsittacus undulatus, the significance of a conspecific alarm call was investigated in two seasons, winter and spring. Two qualitatively different behavioral responses were displayed by the receivers in reply to playbacks: call(s) and/or taking flight(s). The comparative analysis of the number of birds responding to the alarm and to the control signals revealed two major facts: 1) in both seasons, the responses to the alarm signal were only observed for females, not for males, 2) qualitatively, females exhibited a great inter-season variability in their behavioral responses to the hearing of an alarm call. In winter, the females were more predisposed to emit acoustic responses while in spring they mainly took flight.

Acoustic Stimulation↗