Latency modulation of collicular neurons induced by electric stimulation of the auditory cortex in Hipposideros pratti: In vivo intracellular recording

Abstract

In the auditory pathway, the inferior colliculus (IC) receives and integrates excitatory and inhibitory inputs from the lower auditory nuclei, contralateral IC, and auditory cortex (AC), and then uploads these inputs to the thalamus and cortex. Meanwhile, the AC modulates the sound signal processing of IC neurons, including their latency (i.e., first-spike latency). Excitatory and inhibitory corticofugal projections to the IC may shorten and prolong the latency of IC neurons, respectively. However, the synaptic mechanisms underlying the corticofugal latency modulation of IC neurons remain unclear. Thus, this study probed these mechanisms via in vivo intracellular recording and acoustic and focal electric stimulation. The AC latency modulation of IC neurons is possibly mediated by pre-spike depolarization duration, pre-spike hyperpolarization duration, and spike onset time. This study suggests an effective strategy for the timing sequence determination of auditory information uploaded to the thalamus and cortex.

Emergence and function of cortical offset responses in sound termination detection

“…The wire electrode was fixed in pulled capillary glass (tip: <10 µm) filled with saline and then inserted into AAF (~300 µm). Monophasic square wave pulse was generated with electronic stimulator as pulse train (pulse duration: 0.1 ms; frequency: 50 Hz; train number: 20); intensity: 30 μA (similar to the method described in Peng et al, 2017 ). At the same time, electrophysiology recordings with 64-channel electrode were performed in MGB.…”

Emergence and function of cortical offset responses in sound termination detection

“…Wire electrode was fixed in pulled capillary glass (tip:<10 µm) filled with saline and then inserted into AAF (~300 µm). Monophasic square wave pulse were generated with electronic stimulator as pulse train (pulse duration: 0.1 ms; frequency: 50 Hz; train number: 20; intensity: 30 uA (similar to method described in (Peng et al, 2017)). In the same time electrophysiology recordings with 64-channels electrode were performed in MGB.…”

“…stimulator as pulse train (pulse duration: 0.1 ms; frequency: 50 Hz; train number: 20; intensity: 30 uA (similar to method described in (Peng et al, 2017)). In the same time electrophysiology recordings with 64-channels electrode were performed in MGB.…”