Eatock Lab
This lab studies mechanosensory signaling by the inner ear. They focus on the mouse utricle, where they have access to mechanosensitive receptor cells and primary afferent neurons. In this circuit, they can address fundamental neurobiological questions, such as mechanotransduction, the nature of a simple sensory map, how transmission occurs across unique calyceal synapses, and how different kinds of informatigaon are encoded in the spike rate and timing of primary afferent neurons.
Ruth Anne Eatock
Emily Scott
Christopher Luong
Antonia (Toni) González Garrido
Olivia Lutz
Marina Kabirova
Recent
Contributions of mirror-image hair cell orientation to mouse otolith organ and zebrafish neuromast function (Preprint, 2025)
Otolith organs in the inner ear and neuromasts in the fish lateral-line harbor two populations of hair cells oriented to detect stimuli in opposing directions. The underlying mechanism is highly conserved: the transcription factor EMX2 is regionally expressed in just one hair cell population and acts through the receptor GPR156 to reverse cell orientation relative to the other population. In mouse and zebrafish, loss of Emx2 results in sensory organs that harbor only one hair cell orientation and are not innervated properly. In zebrafish, Emx2 also confers hair cells with reduced mechanosensory properties. Here, scholars leverage mouse and zebrafish models lacking GPR156 to determine how detecting stimuli of opposing directions serves vestibular function, and whether GPR156 has other roles besides orienting hair cells.
KV1.8 (Kcna10) potassium channels enhance fast, linear signaling in vestibular hair cells and facilitate vestibulomotor reflexes and balance (2025)
Vestibular hair cells (HCs) faithfully and rapidly detect head motions and gravity, driving motor reflexes that stabilize balance and gaze during locomotion. With the transition from water to land, the amniote vestibular inner ear added type I HCs, which differ from amniote type II HCs and anamniote HCs by their large calyx afferent synapse, non-quantal afferent transmission, and a large, low-voltage-activated K+ conductance (gK,L). Here, scholars compared KV1.8-null (Kcna10−/−) and control animals to see how KV1.8 affects function as measured by receptor potentials and nonquantal postsynaptic potentials evoked by direct hair bundle motions, and by vestibulomotor behaviors.
The potassium channel subunit KV1.8 (Kcna10) is essential for the distinctive outwardly rectifying conductances of type I and II vestibular hair cells (2024)
In amniotes, head motions and tilt are detected by two types of vestibular hair cells (HCs) with strikingly different morphology and physiology. Mature type I HCs express a large and very unusual potassium conductance, gK,L, which activates negative to resting potential, confers very negative resting potentials and low input resistances, and enhances an unusual non-quantal transmission from type I cells onto their calyceal afferent terminals. Following clues pointing to KV1.8 (Kcna10) in the Shaker K channel family as a candidate gK,L subunit, researchers compared whole-cell voltage-dependent currents from utricular HCs of KV1.8-null mice and littermate controls.
Effects of transient, persistent, and resurgent sodium currents on excitability and spike regularity in vestibular ganglion neurons (2024)
Vestibular afferent neurons occur as two populations with differences in spike timing regularity that are independent of rate. The more excitable regular afferents have lower current thresholds and sustained spiking responses to injected currents, while irregular afferent neurons have higher thresholds and transient responses. Differences in expression of low-voltage-activated potassium (K LV ) channels are emphasized in models of spiking regularity and excitability in these neurons, leaving open the potential contributions of the voltage-gated sodium (Na V ) channels responsible for the spike upstroke. In this paper, authors investigated the impact of different Na V current modes (transient, persistent, and resurgent) with whole-cell patch clamp experiments in mouse vestibular ganglion neurons (VGNs), the cultured and dissociated cell bodies of afferents.
Voltage-gated ion channels and firing patterns of vestibular afferents
The vestibular inner ear transmits head-motion information to the brain via two populations of vestibular ganglion neurons (VGN). One of the current projects at the Eatock lab involves exploring the roles of voltage-gated sodium (NaV) currents, responsible for driving the upstroke of AP in VGN’s spike timing.