A sensorimotor area (NIf) is required for the production of learned vocalizations

Sensory feedback is essential for the acquisition of complex motor behaviors, including birdsong. In zebra finches, auditory feedback is relayed to the descending motor pathway primarily through the nucleus interfacialis nidopalii (NIf). NIf projects to HVC - a premotor region essential for song, which projects to RA, a motor cortex analogue brain area that drives muscle activity required for vocalizations. NIf is also essential for ‘sleep replay’, a recapitulation of song-related neural dynamics in the motor pathway during sleep. Despite being one of the major inputs to the song control pathway, there is no known role for NIf in the production of zebra finch song. To address this, we reversibly inactivated NIf using TTX or Muscimol in 13 birds. We compared songs before and during inactivation and found large effects of NIf inactivation on song structure. Vocalizations after NIf inactivation resembled subsong, highly variable utterances typical of the very early phases of song learning. Subsong is driven by LMAN, the output nucleus of an avian basal ganglia circuit that projects to RA. To verify that NIf inactivations indeed switched song control from HVC to LMAN, we inactivated LMAN in conjunction with NIf in four birds. As with LMAN inactivations after HVC lesions, this manipulation led to a complete cessation of singing. We also lesioned NIf using ibotenic acid and saw the song recover within a day, consistent with previous studies. Our results show that NIf input to HVC is acutely necessary for generating learned vocal behavior in songbirds, and that in its absence vocal production reverts to subsong driven by LMAN. Absent NIf input, the song circuit reorganizes and recovers its ability to produce pre-lesion song over the course of 1-2 days, suggesting a redundant role for NIf that can be assumed by other parts of the song circuit

Компаративний аналіз привабливості стратегічних зон господарювання підприємства

Запропоновано методику компаративного аналізу привабливості стратегічних зон господарювання підприємства з використанням методів багатокритеріального оцінювання.Предложена методика компаративного анализа привлекательности стратегических зон хозяйствования предприятия с использованием методов многокритериального оценивания.The article proposed a method for comparative analysis of attractiveness of enterprise strategic bussines unit using methods of multi-criteria evaluation

Functional MRI of Auditory Responses in the Zebra Finch Forebrain Reveals a Hierarchical Organisation Based on Signal Strength but Not Selectivity

BACKGROUND: Male songbirds learn their songs from an adult tutor when they are young. A network of brain nuclei known as the 'song system' is the likely neural substrate for sensorimotor learning and production of song, but the neural networks involved in processing the auditory feedback signals necessary for song learning and maintenance remain unknown. Determining which regions show preferential responsiveness to the bird's own song (BOS) is of great importance because neurons sensitive to self-generated vocalisations could mediate this auditory feedback process. Neurons in the song nuclei and in a secondary auditory area, the caudal medial mesopallium (CMM), show selective responses to the BOS. The aim of the present study is to investigate the emergence of BOS selectivity within the network of primary auditory sub-regions in the avian pallium. METHODS AND FINDINGS: Using blood oxygen level-dependent (BOLD) fMRI, we investigated neural responsiveness to natural and manipulated self-generated vocalisations and compared the selectivity for BOS and conspecific song in different sub-regions of the thalamo-recipient area Field L. Zebra finch males were exposed to conspecific song, BOS and to synthetic variations on BOS that differed in spectro-temporal and/or modulation phase structure. We found significant differences in the strength of BOLD responses between regions L2a, L2b and CMM, but no inter-stimuli differences within regions. In particular, we have shown that the overall signal strength to song and synthetic variations thereof was different within two sub-regions of Field L2: zone L2a was significantly more activated compared to the adjacent sub-region L2b. CONCLUSIONS: Based on our results we suggest that unlike nuclei in the song system, sub-regions in the primary auditory pallium do not show selectivity for the BOS, but appear to show different levels of activity with exposure to any sound according to their place in the auditory processing stream

Motor circuits are required to encode a sensory model for imitative learning

Premotor circuits help generate imitative behaviors and can be activated during observation of another animal′s behavior, leading to speculation that these circuits participate in sensory learning that is important to imitation. Here we tested this idea by focally manipulating the brain activity of juvenile zebra finches, which learn to sing by memorizing and vocally copying the song of an adult tutor. Tutor song–contingent optogenetic or electrical disruption of neural activity in the pupil′s song premotor nucleus HVC prevented song copying, indicating that a premotor structure important to the temporal control of birdsong also helps encode the tutor song. In vivo multiphoton imaging and neural manipulations delineated a pathway and a candidate synaptic mechanism through which tutor song information is encoded by premotor circuits. These findings provide evidence that premotor circuits help encode sensory information about the behavioral model before shaping and executing imitative behaviors.Organismic and Evolutionary Biolog

Learning-related neuronal activation in the zebra finch song system nucleus HVC in response to the bird's own song.

Like many other songbird species, male zebra finches learn their song from a tutor early in life. Song learning in birds has strong parallels with speech acquisition in human infants at both the behavioral and neural levels. Forebrain nuclei in the 'song system' are important for the sensorimotor acquisition and production of song, while caudomedial pallial brain regions outside the song system are thought to contain the neural substrate of tutor song memory. Here, we exposed three groups of adult zebra finch males to either tutor song, to their own song, or to novel conspecific song. Expression of the immediate early gene protein product Zenk was measured in the song system nuclei HVC, robust nucleus of the arcopallium (RA) and Area X. There were no significant differences in overall Zenk expression between the three groups. However, Zenk expression in the HVC was significantly positively correlated with the strength of song learning only in the group that was exposed to the bird's own song, not in the other two groups. These results suggest that the song system nucleus HVC may contain a neural representation of a memory of the bird's own song. Such a representation may be formed during juvenile song learning and guide the bird's vocal output

Correlation coefficients of the relationship between the number of elements copied from the tutor song and Zenk expression in the HVC, RA and Area X for groups of birds exposed to the tutor song (TUTOR), bird’s own song (BOS), or novel conspecific song (NOVEL).

a<p>NS, Not Significant; p-values <0.05 were considered significant.</p

Mean (± SEM) number of Zenk-positive nuclei per mm² in the song system brain nuclei (A) HVC, (B) RA and (C) Area X, for groups of male zebra finches exposed to tutor song (TUTOR), bird’s own song (BOS) or novel conspecific song (NOVEL).

<p>Mean (± SEM) number of Zenk-positive nuclei per mm² in the song system brain nuclei (A) HVC, (B) RA and (C) Area X, for groups of male zebra finches exposed to tutor song (TUTOR), bird’s own song (BOS) or novel conspecific song (NOVEL).</p

Scatter plots of mean number of Zenk immunoreactive cell nuclei per mm² in the song system nucleus HVC, in relation to the percentage of song elements copied from the tutor song (song similarity) for groups of birds exposed to (A) tutor song (TUTOR), (B) bird’s own song (BOS) or (C) novel conspecific song (NOVEL).

<p>Note that y-axis has a log scale.</p

Schematic diagrams of composite views of parasagittal sections of the songbird brain.

<p>A. Diagram of a songbird brain giving approximate positions of nuclei and brain regions involved in auditory perception and memory. Yellow areas represent brain regions that show increased neuronal activation when the bird hears song. B. Diagram of a songbird brain giving approximate positions of nuclei and brain regions involved in vocal production and sensorimotor learning. Orange nuclei in the song system show increased neuronal activation when the bird is singing. Abbreviations: CLM, caudal lateral mesopallium; CMM, caudal medial mesopallium; DLM, nucleus dorsolateralis anterior, pars medialis; HVC, acronym used as a proper name; L1, L2, L3, subdivisions of Field L; LMAN, lateral magnocellular nucleus of the anterior nidopallium; NCM, caudal medial nidopallium; nXIIts, tracheosyringeal portion of the nucleus hypoglossus; RA, robust nucleus of the arcopallium. Modified and reproduced, with permission, from references <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041556#pone.0041556-Bolhuis5" target="_blank">[9]</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041556#pone.0041556-Moorman2" target="_blank">[60]</a>, copyright 2010 Nature Publishing Group. All rights reserved.</p