A Modeling Study of Notch Noise Responses of Type III Units in the Gerbil Dorsal Cochlear Nucleus

2006 ◽  
Vol 34 (4) ◽  
pp. 697-708 ◽  
Author(s):  
Xiaohan Zheng ◽  
Herbert F. Voigt
Keyword(s):  
Cochlear Nucleus ◽  
Dorsal Cochlear Nucleus ◽  
Type Iii ◽  
Modeling Study

Response properties of type II and type III units in dorsal cochlear nucleus

1982 ◽  
Vol 6 (2) ◽  
pp. 153-169 ◽  
Author(s):  
Eric D. Young ◽  
Herbert F. Voigt
Keyword(s):  
Cochlear Nucleus ◽  
Dorsal Cochlear Nucleus ◽  
Type Ii ◽  
Response Properties ◽  
Type Iii

Type III Units in the Gerbil Dorsal Cochlear Nucleus May Be Spectral Notch Detectors

2001 ◽  
Vol 29 (10) ◽  
pp. 887-896 ◽  
Author(s):  
Jessica E. Parsons ◽  
Eric Lim ◽  
Herbert F. Voigt
Keyword(s):  
Cochlear Nucleus ◽  
Dorsal Cochlear Nucleus ◽  
Type Iii

Cross-correlation analysis of inhibitory interactions in dorsal cochlear nucleus

1990 ◽  
Vol 64 (5) ◽  
pp. 1590-1610 ◽  
Author(s):  
H. F. Voigt ◽  
E. D. Young
Keyword(s):  
Correlation Analysis ◽  
Cochlear Nucleus ◽  
Cross Correlation ◽  
Discharge Rate ◽  
Dorsal Cochlear Nucleus ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Cross Correlation Analysis ◽  
The Cross

1. Cross-correlation analysis was used to study the organization of inhibitory connections between type II or type III units and type IV principal cells in cat dorsal cochlear nucleus (DCN). Pairs of units were isolated using two microelectrodes so that information about the distance over which connections are made could be analyzed. Data were obtained from 51 pairs consisting of a type II and a type IV unit and from 22 pairs consisting of a type III and a type IV unit. The analyses in this paper concentrate on type II-type IV pairs. 2. Inhibitory troughs (ITs) are observed in the cross-correlograms of type II-type IV pairs (21/51 cases). An IT is a transient decrease in discharge probability in the postsynaptic (type IV) unit immediately after spikes in the presynaptic unit (type II). The average latency to the start of ITs is 0.73 ms, and the troughs are asymmetric with a faster leading phase. Small excitatory peaks accompany the ITs in type II units, but these are probably secondary effects associated with the IT. ITs are consistent with a monosynaptic, inhibitory connection between type II and type IV units. A variety of evidence suggests that type II responses are recorded from vertical cells, an interneuron in the deep layer of the DCN that may be glycinergic. 3. The cross-correlograms of type III-type IV pairs are more complex and variable than those of type II-type IV pairs--ITs are seen in 4/22 cases, and peaks of correlation that are symmetrically located around the origin (central mound or CM) are seen in 4/22 cases; two cases have both an IT and a CM. CMs result from shared sources of input. Whereas type II-type IV correlogram features change primarily in amplitude as stimulus conditions change, correlogram features in some type III-type IV pairs change qualitatively with stimulus conditions; correlograms are flat for some stimuli and show ITs or CMs or mixtures of the two for others. This variability suggests that the circuitry associated with type III-type IV pairs is more complex than a monosynaptic connection, and further analysis of type III-type IV pairs was not done. 4. The strength of inhibition for an IT is measured as the area under the IT (effectiveness) and as effectiveness divided by the postsynaptic discharge rate (association index).(ABSTRACT TRUNCATED AT 400 WORDS)

Evidence of Stimulus-Dependent Correlated Activity in the Dorsal Cochlear Nucleus of Decerebrate Gerbils

1997 ◽  
Vol 78 (1) ◽  
pp. 229-247 ◽  
Author(s):  
Kevin A. Davis ◽  
Herbert F. Voigt
Keyword(s):  
Cochlear Nucleus ◽  
Broadband Noise ◽  
Dorsal Cochlear Nucleus ◽  
Inhibitory Input ◽  
Mongolian Gerbils ◽  
Type Ii ◽  
Type Iii ◽  
Principal Cells ◽  
Type Iv ◽  
Correlated Activity

Davis, Kevin A. and Herbert F. Voigt. Evidence of stimulus-dependent correlated activity in the dorsal cochlear nucleus of decerebrate gerbils. J. Neurophysiol. 78: 229–247, 1997. Cross-correlation analysis of simultaneously recorded spike trains was used to study the internal organization of the dorsal cochlear nucleus (DCN) of unanesthetized decerebrate Mongolian gerbils. The goal was to test the model (adapted from cat) that its principal cells (type III and type IV units) receive three sources of shared auditory input: excitatory input from the auditory nerve; inhibitory input from DCN interneurons (vertical cells; type II and typeIII-i units) that respond vigorously to tones; and inhibitory input from ventral cochlear nucleus principal cells (D-stellate cells; wideband inhibitors) that conversely respond vigorously to noise. Records of spontaneous and/or driven activities (to long-duration tones and frozen broadband noise) were obtained for 51 pairs consisting of type II, type III, and type IV units; type III units inhibited by low-level noise were subclassified as type III-i units. Pairs were isolated with two electrodes to study the effect of differences in unit best frequencies (BFs) on correlation. All correlated pairs composed of type III and type IV units (17 of 31 pairs) showed central mounds (CMs), indicative of shared input, in their cross-correlograms. These data exhibited two important properties: pairs with similar BFs were more likely to show CMs, and the shape of the CMs was stimulus dependent. That is, CM width typically changed sharply from wide to narrow with increasing level; significantly, transition-level CMs were either a composite of these shapes or not present. The transition to only narrow CMs occurred above the thresholds of type II and type III-i units to tones, but below their thresholds to noise. Cross-correlograms derived from the tone-evoked activities of pairs involving type II units (3 of 6 pairs) showed inhibitory troughs (ITs); unexpectedly, type III-i units were involved in both IT and CM pairs, suggesting that this unit type may reflect recordings from both vertical and principal cells. Overall, the results are interpretable in terms of the model of gerbil DCN that was adapted from cat, suggesting that the model generalizes across species. Compared with cat, however, gerbil principal cell responses (predominantly type III unit properties) are less dominated by inhibition.

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