Acoustic response properties of single units and unit clusters in the midbrain of the goldfish.

1992 ◽  
Vol 91 (4) ◽  
pp. 2398-2398 ◽  
Author(s):  
Z. Lu ◽  
R. Fay
Keyword(s):  
Single Units ◽  
Acoustic Response ◽  
Response Properties

Response properties of single units in an association area of the kitten neocortex

1976 ◽  
Vol 16 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Kathleen S. Mayers ◽  
Richard T. Robertson ◽  
Timothy J. Teyler ◽  
Richard F. Thompson
Keyword(s):  
Single Units ◽  
Response Properties ◽  
Association Area

Response properties of single units in the dorsal nucleus of the lateral lemniscus and paralemniscal zone of an echolocating bat

1993 ◽  
Vol 69 (3) ◽  
pp. 842-859 ◽  
Author(s):  
E. Covey
Keyword(s):  
Sound Level ◽  
Single Units ◽  
Superior Olivary Complex ◽  
Inhibitory Input ◽  
Gamma Aminobutyric Acid ◽  
Lateral Lemniscus ◽  
Response Properties ◽  
Binaural Interaction ◽  
Dorsal Nucleus ◽  
Interaural Level Differences

1. Connectional evidence suggests that the dorsal nucleus of the lateral lemniscus (DNLL) and the paralemniscal zone (PL) function as centers for binaural analysis interposed between the superior olivary complex and the midbrain. In addition, the DNLL is known to be a major source of inhibitory input to the midbrain. The aim of this study was to characterize the response properties of neurons in DNLL and PL of the echolocating bat Eptesicus fuscus, a species that utilizes high-frequency hearing and that might be expected to have a large proportion of neurons responsive to interaural differences in sound level. 2. Auditory stimuli were presented monaurally or binaurally to awake animals, and responses of single units were recorded extra-cellularly with the use of glass micropipettes. 3. Below the ventrolateral border of the inferior colliculus is a region that contains large gamma-aminobutyric acid-positive neurons. On the basis of its immunohistochemical reactivity, this entire region could be considered as DNLL. However, within the area, there was an uneven distribution of binaural responses. Caudally, binaural neurons made up 84% (41/49) of those tested, but rostrally only 29% (6/21). For this reason the rostral area is considered as a separate functional subdivision and referred to as the dorsal paralemniscal zone (DPL). PL is located ventral to DPL and medial to the intermediate and ventral nuclei of the lateral lemniscus; in PL 88% (14/16) of neurons were binaural. 4. Most neurons responded only to a contralateral stimulus when sounds were presented monaurally. Out of 49 neurons in DNLL, 42 responded only to a contralateral sound, 1 responded only to an ipsilateral sound, and 6 responded to sound at either ear. In the DPL, all of the 21 neurons tested responded to a contralateral sound and none to an ipsilateral sound. Out of 16 neurons in the PL, 11 responded only to a contralateral sound, 1 responded only to an ipsilateral sound, and 4 responded to sound at either ear. 5. When sounds were presented at both ears simultaneously, several different patterns of binaural interaction occurred. The most common pattern was suppression of the response to sound at one ear by sound at the other ear. In DNLL, 57% (28/49) of neurons showed this type of binaural interaction. Another 10% (5/49) showed facilitation at some interaural level differences and suppression at others, and another 10% (5/49) showed facilitation at some interaural level differences but no suppression.(ABSTRACT TRUNCATED AT 400 WORDS)

Marginal Shell of the Anteroventral Cochlear Nucleus: Single-Unit Response Properties in the Unanesthetized Decerebrate Cat

1997 ◽  
Vol 77 (4) ◽  
pp. 2083-2097 ◽  
Author(s):  
S. Ghoshal ◽  
D. O. Kim
Keyword(s):  
Cochlear Nucleus ◽  
Single Unit ◽  
Unit Response ◽  
Large Majority ◽  
Single Units ◽  
Decerebrate Cat ◽  
Response Properties ◽  
The Core ◽  
Anteroventral Cochlear Nucleus ◽  
Single Unit Response

Ghoshal, S. and D. O. Kim. Marginal shell of the anteroventral cochlear nucleus: single-unit response properties in the unanesthetized decerebrate cat. J. Neurophysiol. 77: 2083–2097, 1997. The marginal shell of the anteroventral cochlear nucleus (AVCN) is anatomically different from its central core. We investigated 38 single units in the shells of 10 cats and contrasted them with 62 single units in the cores of 15 cats. The sites of all shell units were localized with the use of reconstructed electrode tracks. The shell units were divided into acoustically well-driven (68%) and weakly/not-driven (32%) subgroups. The shell units mostly exhibited low spontaneous rates (SRs). Among the well-driven shell units, a large majority (68%) exhibited wide dynamic ranges (≥50 dB) to tones, noise, or both, with some ranges as wide as 89 dB. In contrast, a large majority (80%) of the core units exhibited narrow dynamic ranges (<50 dB) to tones and noise. The poststimulus time histograms (PSTHs) of the well-driven shell units included pause-build (29%), onset (24%), and unusual (33%) types, whereas those of the core units included mainly primary-like (47%) and chopper (29%) types. The excitatory-inhibitory areas (EIAs) of the well-driven shell units included types I/III (47%), III (22%), IV (13%), and II (9%), whereas those of the core units included mainly types III (52%) and I/III (32%). On the basis of Fisher's exact tests, we conclude that the shell and core neural groups of the AVCN are significantly different regarding all of the following physiological characteristics: SR, maximum driven rate, threshold and dynamic range to tones and noise, frequency response area, PSTH type, latency, and EIA type. Wide dynamic ranges of the well-driven shell units suggest that they may play a role in encoding absolute intensity of acoustic stimulus.

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