https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:36884 Wed 26 Aug 2020 14:16:44 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33924 Wed 23 Jan 2019 15:34:09 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35344 Wed 17 Jul 2019 11:45:17 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35596 Wed 11 Sep 2019 14:24:41 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52408 Wed 11 Oct 2023 11:52:32 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17231 K,L. A similar current was first observed at 15 WG but remained relatively small, even at 18 WG. The presence of a “collapsing” tail current indicates a maturing type I hair cell phenotype and suggests the presence of a surrounding calyx afferent terminal. We were also able to record from calyx afferent terminals in 15–18 WG cristae. In voltage clamp, these terminals exhibited fast inactivating inward as well as slower outward conductances, and in current clamp, discharged a single action potential during depolarizing steps. Together, these data suggest the major functional characteristics of type I and type II hair cells and calyx terminals are present by 18 WG. Our study also describes a new preparation for the functional investigation of key events that occur during maturation of human vestibular organs.]]> Wed 11 Apr 2018 14:41:28 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29840 T ≈ 0.25°C per pulse). Afferent spike trains evoked by heat pulse stimuli were diverse and included asynchronous inhibition, asynchronous excitation, and/or phase-locked APs synchronized to each infrared heat pulse. Thermal responses of membrane currents responsible for APs in ganglion neurons were strictly excitatory, with Q₁₀ ≈ 2. In contrast, hair cells responded with a mix of excitatory and inhibitory currents. Excitatory hair cell membrane currents included a thermoelectric capacitive current proportional to the rate of temperature rise (dT/dt) and an inward conduction current driven by ΔT. An iberiotoxin-sensitive inhibitory conduction current was also evoked by ΔT, rising in <3 ms and decaying with a time constant of ∼24 ms. The inhibitory component dominated whole cell currents in 50% of hair cells at −68 mV and in 67% of hair cells at −60 mV. Responses were quantified and described on the basis of first principles of thermodynamics. Results identify key molecular targets underlying heat pulse excitability in vestibular sensory organs and provide quantitative methods for rational application of optical heat pulses to examine protein biophysics and manipulate cellular excitability.]]> Wed 11 Apr 2018 09:55:53 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48758 Wed 05 Apr 2023 13:49:21 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:1544 Sat 24 Mar 2018 08:30:44 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20053 Sat 24 Mar 2018 08:00:04 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:5800 Sat 24 Mar 2018 07:44:55 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:23550 Sat 24 Mar 2018 07:14:09 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38353 Mon 30 Aug 2021 16:06:38 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:377 Mon 24 Sep 2018 16:15:03 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33885 Mon 23 Sep 2019 14:01:51 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:32141 Mon 23 Sep 2019 13:52:53 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50760 24 months) mice had impaired performance in a balance beam task compared to young (3-4 months) adult mice. While there was no qualitative loss of cholinergic axon varicosities in the crista ampullaris of old mice, qPCR analysis revealed reduced expression of nicotinic receptor subunit genes Chrna1, Chrna9, and Chrna10 in the cristae of old relative to young mice. Functionally, single-cell patch clamp recordings taken from type II vestibular hair cells exposed to acetylcholine show reduced conductance through alpha9/10 subunit-containing nicotinic receptors in older mice, despite preserved passive membrane properties and voltage-activated conductances. These findings suggest that cholinergic signaling in the peripheral vestibular sensory organs is vulnerable to aging processes, manifesting in dynamic molecular and functional age-related changes. Given the importance of these organs to our everyday activities, and the dramatic increase in fall incidence in the elderly, further investigation into the mechanisms of altered peripheral vestibular function in older humans is warranted.]]> Mon 07 Aug 2023 14:22:26 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:48979 Fri 21 Apr 2023 09:29:59 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39675 Fri 17 Jun 2022 15:32:12 AEST ]]>