Excitation and inhibition in the dorsal nucleus of the lateral lemniscus influence binaural response properties of neurons in the rat’s inferior colliculus

1999 ◽  
Vol 105 (2) ◽  
pp. 1085-1086
Author(s):  
Jack B. Kelly
Keyword(s):  
Inferior Colliculus ◽  
Lateral Lemniscus ◽  
Response Properties ◽  
Dorsal Nucleus

Differential Response Properties to Amplitude Modulated Signals in the Dorsal Nucleus of the Lateral Lemniscus of the Mustache Bat and the Roles of GABAergic Inhibition

1997 ◽  
Vol 77 (1) ◽  
pp. 324-340 ◽  
Author(s):  
Lichuan Yang ◽  
George D. Pollak
Keyword(s):  
Phase Locking ◽  
Modulation Frequency ◽  
Tone Burst ◽  
Differential Response ◽  
Gabaergic Inhibition ◽  
Lateral Lemniscus ◽  
Response Properties ◽  
Dorsal Nucleus ◽  
Modulated Signals ◽  
Onset Response

Yang, Lichuan and George D. Pollak. Differential response properties to amplitude modulated signals in the dorsal nucleus of the lateral lemniscus of the mustache bat and the roles of GABAergic inhibition. J. Neurophysiol. 77: 324–340, 1997. We studied the phase-locking of 89 neurons in the dorsal nucleus of the lateral lemniscus (DNLL) of the mustache bat to sinusoidally amplitude modulated (SAM) signals and the influence that GABAergic inhibition had on their response properties. Response properties were determined with tone bursts at each neuron's best frequency and then with a series of SAM signals that had modulation frequencies ranging from 50–100 to 800 Hz in 100-Hz steps. DNLL neurons were divided into two principal types: sustained neurons (55%), which responded throughout the duration of the tone burst, and onset neurons (45%), which responded only at the beginning of the tone burst. Sustained and onset neurons responded differently to SAM signals. Sustained neurons responded with phase-locked discharges to modulation frequencies ≤400–800 Hz. In contrast, 70% of the onset neurons phase-locked only to low modulation frequencies of 100–300 Hz, whereas 30% of the onset neurons did not phase-lock to any modulation frequency. Signal intensity differentially affected the phase-locking of sustained and onset neurons. Sustained neurons exhibited tight phase-locking only at low intensities, 10–30 dB above threshold. Onset neurons, in contrast, maintained strong phase-locking even at relatively high intensities. Blocking GABAergic inhibition with bicuculline had different effects on the phase-locking of sustained and onset neurons. In sustained neurons, there was an overall decline in phase-locking at all modulation frequencies. In contrast, 70% of the onset neurons phase-locked to much higher modulation frequencies than they did when inhibition was intact. The other 30% of onset neurons phase-locked to SAM signals, although they fired only with an onset response to the same signals before inhibition was blocked. In both cases, blocking GABAergic inhibition transformed their responses to SAM signals into patterns that were more like those of sustained neurons. We also propose mechanisms that could explain the differential effects of GABAergic inhibition on onset neurons that locked to low modulation frequencies and on onset neurons that did not lock to any SAM signals before inhibition was blocked. The key features of the proposed mechanisms are the absolute latencies and temporal synchrony of the excitatory and inhibitory inputs.

scholarly journals Differing Roles of Inhibition in Hierarchical Processing of Species-Specific Calls in Auditory Brainstem Nuclei

2005 ◽  
Vol 94 (6) ◽  
pp. 4019-4037 ◽  
Author(s):  
Ruili Xie ◽  
John Meitzen ◽  
George D. Pollak
Keyword(s):  
Auditory Brainstem ◽  
Lateral Lemniscus ◽  
Response Properties ◽  
Hierarchical Processing ◽  
Tuning Curves ◽  
Neuronal Populations ◽  
Dorsal Nucleus ◽  
Brainstem Nuclei ◽  
Communication Calls ◽  
Species Specific

Here we report on response properties and the roles of inhibition in three brain stem nuclei of Mexican-free tailed bats: the inferior colliculus (IC), the dorsal nucleus of the lateral lemniscus (DNLL) and the intermediate nucleus of the lateral lemniscus (INLL). In each nucleus, we documented the response properties evoked by both tonal and species-specific signals and evaluated the same features when inhibition was blocked. There are three main findings. First, DNLL cells have little or no surround inhibition and are unselective for communication calls, in that they responded to ∼97% of the calls that were presented. Second, most INLL neurons are characterized by wide tuning curves and are unselective for species-specific calls. The third finding is that the IC population is strikingly different from the neuronal populations in the INLL and DNLL. Where DNLL and INLL neurons are unselective and respond to most or all of the calls in the suite we presented, most IC cells are selective for calls and, on average, responded to ∼50% of the calls we presented. Additionally, the selectivity for calls in the majority of IC cells, as well as their tuning and other response properties, are strongly shaped by inhibitory innervation. Thus we show that inhibition plays only limited roles in the DNLL and INLL but dominates in the IC, where the various patterns of inhibition sculpt a wide variety of emergent response properties from the backdrop of more expansive and far less specific excitatory innervation.

scholarly journals Responses from two firing patterns in inferior colliculus neurons to stimulation of the lateral lemniscus dorsal nucleus

2016 ◽  
Vol 11 (5) ◽  
pp. 787 ◽  
Author(s):  
Ning-yu Wang ◽  
Xiao-ting Li ◽  
Yan-jun Wang ◽  
Zhi-qing Xu ◽  
Jin-feng Liu ◽  
...  
Keyword(s):  
Inferior Colliculus ◽  
Lateral Lemniscus ◽  
Firing Patterns ◽  
Dorsal Nucleus ◽  
Stimulation Of
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