Biology subjects

Wong, A. B.

Publications and source records attributed to Wong, A. B..

3 recordsLinked to original sources

bioRxiv2021

Neurometric correlates to sensitive high-frequency sound amplitude modulation detection by mice

Amplitude modulation (AM) is a common feature of natural sounds, including speech and animal vocalizations. Here, we used operant conditioning and in vivo electrophysiology to determine the AM detection threshold of mice as well as its underlying neuronal encoding. Mice were trained in a Go-NoGo task to detect the transition to AM within a noise stimulus designed to prevent the use of spectral side-bands or a change in intensity as alternative cues. Our results indicate that mice, in comparison with other species, detect high modulation frequencies up to 512 Hz well, but show much poorer performance at low frequencies. Our in vivo multielectrode recordings in the inferior colliculus (IC) of both anesthetized and awake mice revealed a few single units with remarkable phase-locking ability to 512 Hz modulation, but not sufficient to explain the good behavioral detection at that frequency. Using a model of the population response that combined dimensionality reduction with threshold detection, we reproduced the general band-pass characteristics of behavioral detection based on a subset of neurons showing the largest firing rate change (both increase and decrease) in response to AM, suggesting that these neurons are instrumental in the behavioral detection of AM stimuli by the mice. New and NoteworthyThe amplitude of natural sounds, including speech and animal vocalizations, often shows characteristic modulations. We examined the relationship between neuronal responses in the mouse inferior colliculus and the behavioral detection of amplitude modulation in sound, and modelled how the former can give rise to the latter. Our model suggests that behavioral detection can be well explained by the activity of a subset of neurons showing the largest firing rate changes in response to AM.

neuroscience↗

bioRxiv2019

Tonotopic and multisensory organization of the mouse dorsal inferior colliculus revealed by two-photon imaging

The dorsal (DCIC) and lateral cortices (LCIC) of the inferior colliculus are major targets of the auditory and non-auditory cortical areas, suggesting a role in complex multimodal information processing. However, relatively little is known about their functional organization. We utilized in vivo two-photon Ca2+ imaging in awake mice expressing GCaMP6s in GABAergic or non-GABAergic neurons in the IC to investigate their spatial organization. We found different classes of temporal response, which we confirmed with simultaneous juxtacellular electrophysiology. Both GABAergic and non-GABAergic neurons showed spatial microheterogeneity in their temporal responses. In contrast, a robust reversed rostromedial-caudolateral gradient of frequency tuning was conserved between the two groups, and even among the subclasses. This, together with the existence of a subset of neurons sensitive to spontaneous movements, provides functional evidence for redefining the border between DCIC and LCIC.

neuroscience↗

bioRxiv2018

TRPC3 is essential for functional heterogeneity of cerebellar Purkinje cells

Despite the canonical homogenous character of its organization, the cerebellum plays differential computational roles in distinct types of sensorimotor behaviors. However, the molecular and cell physiological underpinnings are unclear. Here we determined the contribution of transient receptor potential cation channel type C3 (TRPC3) to signal processing in different cerebellar modules. Using gain-of-function and loss-of-function mouse models, we found that TRPC3 controls the simple spike activity of zebrin-negative (Z-), but not of zebrin-positive (Z+), Purkinje cells. Moreover, in vivo TRPC3 also regulated complex spike firing and its interaction with simple spikes exclusively in Z- Purkinje cells. Finally, we found that eyeblink conditioning, related to Z- modules, but not compensatory eye movement adaptation, linked to Z+ modules, was affected in TRPC3 loss-of-function mice. Together, our results indicate that TRPC3 is essential for the cellular heterogeneity that introduces distinct physiological properties in an otherwise homogeneous population of Purkinje cells, conjuring functional heterogeneity in cerebellar sensorimotor integration.

neuroscience↗