Biology subjects

Veit, L.

Publications and source records attributed to Veit, L..

6 recordsLinked to original sources

bioRxiv2026

Birdsong modification with food reward

Songbirds, such as Bengalese finches (Lonchura striata domestica) produce syntactically organized vocal sequences, composed of individual syllables strung together in variable order. Adult birds can learn to modify transition probabilities between syllables through sequence modification training: when punishing one transition with manipulated auditory feedback, birds will gradually reduce the targeted transition. This protocol is thought to rely on a circuit for vocal-auditory monitoring of the birds own song. Despite the overwhelming usefulness of food rewards for other kinds of trained animal behavior, reinforcing birdsong features with food rewards has remained elusive, possibly because the slow timescale of food reward does not match the fast and precise vocal-auditory feedback loops underlying learned birdsong. Here, we use second-order conditioning to selectively increase the frequency of target transitions in song with food rewards. Bengalese finches learned to associate a delayed primary reinforcer (food delivery by an automated feeder after song ends) with a secondary reinforcer (a short click sound). We then reinforced specific target syllables with the click during ongoing song, leading birds to selectively increase the frequency of the targeted syllable transitions. Learned changes were specific to the target and evident in catch trials without reinforcement, indicative of a learning process. Our results demonstrate that song control circuits can learn from different feedback modalities, including learned associations with food reward.

animal behavior and cognition↗

bioRxiv2026

Syllable repetition reveals links between distant phrases in birdsong

Repeated execution of individual behavioural units is a common feature of many learned motor behaviours such as dance, music, and birdsong. Little is known about the neuronal control of such learned motor sequences, and specifically, how the number of variable repetitions is determined. The songs of Bengalese finches (Lonchura striata domestica) consist of individual syllables which can repeat a variable number of times (repeat number) to form a repeat phrase. Like vocal sequences in other animals, Bengalese finch song syntax is typically modelled as a Markov chain, where the choice to repeat the same syllable type or switch to a different one is made stochastically after each syllable, before the next syllable is produced. Here, we report that repeat numbers of adjacent and distant repeat phrases in the song can be correlated across specific pairs of phrases. These hidden links between distinct phrases challenge existing models of song syntax where the number of repetitions is independently determined for each syllable type. Instead, they suggest an organisation where a joint factor can control multiple nonadjacent phrases in a song. Repeat phrases in Bengalese finches may therefore be particularly suited to study the neuronal mechanisms underlying long-range dependencies in complex vocal sequences.

animal behavior and cognition↗

bioRxiv2025

Real-Time Segmentation and Classification of Birdsong Syllables for Learning Experiments

Songbirds are essential animal models for studying neuronal and behavioral mechanisms of learned vocalizations. Bengalese finch (Lonchura striata domestica) songs contain a limited number of acoustically distinct syllable types, which are combined into variable sequences. This makes them ideal to investigate the composition of vocal sequences. Many closed-loop experiments require the online recognition of a specific target syllable while the bird is singing, for example when introducing specific song modifications through reinforcement learning. In this protocol, a specific target syllable is covered with a short burst of white noise, which masks auditory feedback of the birds own song, and leads the bird to avoid the targeted syllable in future song renditions. Existing tools for this learning protocol require manual creation of spectral templates and have limited flexibility to adapt to new experiments. We here present Moove (Marking Online using Only the Onsets of Vocal Elements), a novel approach to real-time syllable segmentation and classification of Bengalese finch songs. A convolution-based audio encoder with a simple multi-layer perceptron is used for onset and offset segmentation of individual syllables, and syllable classification is performed by a convolutional neural network. Crucially Moove classifies syllables using only acoustic information from the first part of the syllable, while the syllable is still ongoing. This allows reinforcement or punishment to be applied with high accuracy and short latency after syllable onset, enabling effective operant conditioning experiments. The fast online annotation of all recorded syllables allows targeting syllables based on their sequence context, while keeping classification itself free from influence by acoustic information from surrounding syllables. To validate this tool, we conducted a learning experiment on one adult male Bengalese finch. The bird learned to avoid the targeted syllable sequence with comparable outcomes to previous learning experiments. Our results show that Moove can correctly segment and classify Bengalese finch syllables in real time for learning experiments. Moove could be used for other closed-loop experiments such as manipulation of auditory feedback, song-triggered neuronal microstimulation, optogenetics, or reward delivery. This makes Moove a crucial tool for future investigations of birdsong sequencing.

animal behavior and cognition↗

bioRxiv2025

Antibiotic production reduces the cost of resource cheaters in Streptomyces coelicolor

Soil is a competitive environment containing a variety of resources used for bacterial growth. Complex polysaccharides, like chitin or starch, require the secretion of enzymes that degrade these resources into smaller units before they can be consumed. However, exoenzymes and the products they create are public goods, meaning they can be used by competitors, called "cheaters", who benefit from public goods even if they do not produce enzymes themselves. Here, we test the hypothesis that antibiotics produced by Streptomyces are used to privatize public goods by restricting access to resource cheaters. Using experiments with Streptomyces coelicolor and Bacillus subtilis, we first show that B. subtilis cheating significantly reduces S. coelicolor fitness on complex medium (starch) but not on a simple carbon source (maltose) which does not require exoenzyme secretion. Next, we show that antibiotics produced by S. coelicolor markedly increase fitness against resource cheaters, despite evidence that antibiotic production is metabolically costly. Finally, we find that the benefits of antibiotic production and the costs of resource cheating are both higher during growth on lower resource concentrations. Our results provide novel insights into the context-dependent costs and benefits of antibiotic secretion in Streptomyces and highlight the role of resource complexity and concentration in mediating competitive strategies in bacteria.

evolutionary biology↗

bioRxiv2023

Lesions in a songbird vocal circuit increase variability in song syntax

Complex motor skills like speech and dance are composed of ordered sequences of simpler elements, but the neuronal basis for syntactic ordering of individual actions into sequences is poorly understood. Birdsong is a learned vocal behavior composed of syntactically ordered sequences of individual syllables. Activity in song premotor nucleus HVC (proper name) has been linked to the control of syllable sequencing, but sequencing may also be affected by its recurrent inputs. We here test the contribution of one of HVCs inputs, mMAN (medial magnocellular nucleus of the anterior nidopallium), to the variable songs of adult male Bengalese finches (Lonchura striata domestica). The syntax of Bengalese song includes several patterns: 1) chunks, where syllables follow stereotypical order 2) branch points, where a given syllable can be followed by two or more different syllables in a probabilistic manner and 3) repeat phrases, where an individual syllable is repeated a variable number of times. We found that after bilateral lesions of mMAN, the acoustic structure of syllables remained largely intact, but sequencing became more variable for each of these patterns, seen by breaks in previously stereotyped chunks, increased uncertainty at branch points and increased variability of repeat numbers. This increase in sequencing variability highlights the potential importance of regions projecting to HVC in the ordering of vocal elements. Previous studies on zebra finches found little effect of mMAN lesions on their relatively stereotyped adult song. In contrast, our results suggest that mMAN contributes to sequencing the variable songs of Bengalese finches and highlight the utility of species with more complex song syntax in investigating neuronal control of ordered motor sequences.

neuroscience↗

bioRxiv2020

Songbirds can learn flexible contextual control over syllable sequencing

The flexible control of sequential behavior is a fundamental aspect of speech, enabling endless reordering of a limited set of learned vocal elements (syllables or words). Songbirds are phylogenetically distant from humans but share both the capacity for vocal learning and neural circuitry for vocal control that includes direct pallial-brainstem projections. Based on these similarities, we hypothesized that songbirds might likewise be able to learn flexible, moment by-moment control over vocalizations. Here, we demonstrate that Bengalese finches (Lonchura striata domestica), which sing variable syllable sequences, can learn to rapidly modify the probability of specific sequences (e.g. ab-c versus ab-d) in response to arbitrary visual cues. Moreover, once learned, this modulation of sequencing occurs immediately following changes in contextual cues and persists without external reinforcement. Our findings reveal a capacity in songbirds for learned contextual control over syllable sequencing that parallels human cognitive control over syllable sequencing in speech.

neuroscience↗