Biology subjects

Waidmann, E. N.

Publications and source records attributed to Waidmann, E. N..

5 recordsLinked to original sources

bioRxiv2024

Mountable miniature microphones to identify and assign mouse ultrasonic vocalizations

Vocal communication is a major component of animal social behavior. Vocalizations can be learned or innate, and can convey a variety of signals, including territorial limits, the presence of predators, or courtship intent. Mouse ultrasonic vocalizations (USVs) are a promising model in which to study mammalian vocal production circuits. While mouse USVs are innate, mice still show complex vocal behavior, including production of structured song composed of multiple syllable types and the ability to modify their vocal rate and syllable repertoire based on social conditions. Though in courtship interactions male mice produce the majority of the emitted USVs, female mice are capable of emitting USVs. In order to study the underlying mechanisms of vocal production in freely behaving pairs of mice, it is necessary to identify the individual responsible for each syllable in group settings. Previous methods to identify the source of an individual USVs have used high-density microphone arrays and triangulation methods, which involve the use of multiple costly microphones and require implementation of complex computational methods. Here we identified, developed, and used an inexpensive, mountable, ultrasound-sensitive miniature-microphone system to record and identify USVs from individual mice during dual socializing behavior. Our system includes custom circuit boards that can be fitted to individual mice and connected to a variety of existing USV recording systems. We found that these miniature microphones reliably detected mouse USVs, and that a high percentage (90%) of vocalizations could be attributed to a specific animal in a vocalizing pair based on the relative amplitude differences alone. This simple readout method avoids the implementation of complicated triangulation methods. By pairing this method with simultaneous video recording and automated animal body part and identity tracking, we were able to study and describe the broader courtship behavioral landscape, in which USV production is one component. These results offer a promising, low-cost, and simple method that researchers can implement to study the social vocal communication between at least pairs of vocalizing mice.

animal behavior and cognition↗

bioRxiv2024

A Functional and Non-Homuncular Representation of the Larynx in the Primary Motor Cortex of Mice, a Vocal Non-Learner

Vocalization is a complex behavior ranging from fully innate to advanced vocal learning. Vocal learning species possess a vocal primary motor cortex (M1) region that makes direct projections to brainstem vocal motor neurons, which are thought to facilitate learning and fine modulation of vocalizations. Surprisingly, a similar, albeit sparse, direct projection from M1 was found in mice. Mice produce ultrasonic vocalizations (USV) which appear to be mostly innate. Modulation of these USVs is impacted by lesions to this M1 region, but genetic ablation of the cortex leads to few, if any, changes to USVs. It remained unclear whether M1 has any control over the vocal organ in a vocal non-learning species. In the current study, we found that stimulation in different parts of M1 in mice can generate contractions in laryngeal and jaw muscles, with different latencies suggestive of both direct and indirect projections to brainstem vocal motor neurons. Viral tracing reveals both single- and double-labeled populations of cortical neurons that simultaneously innervate laryngeal, jaw, and forelimb motor circuits. Chemical lesions reveal that an anterolateral orofacial region of M1 regulates the number of syllables in vocal sequences. Our results provide evidence that M1 in a vocal non-learner has some influence on vocal musculature, consistent with the continuum hypothesis of vocal learning. They also reveal that the representations of muscles for different behaviors across mouse M1 are more intermixed than previously considered. We discuss how these results impact hypotheses on the evolution of cortical vocal control and motor cortex organization.

neuroscience↗

bioRxiv2022

Cascades of neuronal plasticity in the macaque visual cortex

Primates readily learn new visual objects, with neurons in the inferior temporal cortex exhibiting diminished visual responses to familiar stimuli. The mechanisms of visual plasticity expressed within a neural population are largely unknown. Here we used chronic microwire electrodes in a face-selective cortical area in the macaque to longitudinally track cohorts of neurons across several weeks of exposure to novel faces. Neurons showed gradual adaptation in their late-phase visual responses, with cell-specific time constants ranging from two to twenty days. These time constants were governed by the number of testing days rather than by the cumulative number of stimulus exposures. This gradual buildup of altered visual responses may serve as an internal and graded mark of stimulus familiarity, a central component of visual recognition.

neuroscience↗

bioRxiv2021

Parallel functional subnetworks embedded in the macaque face patch system

During normal vision, our eyes provide the brain with a continuous stream of useful information about the world. How visually specialized areas of the cortex, such as face-selective patches, operate under natural modes of behavior is poorly understood. Here we report that, during the free viewing of videos, cohorts of face-selective neurons in the macaque cortex fractionate into distributed and parallel subnetworks that carry distinct information. We classified neurons into functional groups based on their video-driven coupling with fMRI time courses across the brain. Neurons from each group were distributed across multiple face patches but intermixed locally with other groups at each recording site. These findings challenge prevailing views about functional segregation in the cortex and underscore the importance of naturalistic paradigms for cognitive neuroscience. One-Sentence SummaryNatural visual experience reveals parallel functional subnetworks of neurons embedded within the macaque face patch system

neuroscience↗

bioRxiv2019

Delayed suppression normalizes face identity responses in the primate brain

SummaryThe primate brain is specialized for social visual perception. Previous work indicates that recognition draws upon an internal comparison between a viewed face and an internally stored average face. Here we demonstrate that this comparison takes the form of a delayed, dynamic suppression of face averageness among single neurons. In three macaque face patches, spiking responses to low-identity morphed faces met with a synchronous attenuation starting approximately 200 ms after onset. Analysis showed that a late-emerging V-shaped identity tuning was sometimes superimposed on linear ramp tuning. This pattern could not be ascribed to repetition suppression within a given session. The results indicate that the brains analysis of faces is enhanced through predictive normalization of identity, which increases sensitivity among face-selective neurons to distinctive facial features known to drive recognition.

neuroscience↗