Binaural processing in the dorsal nucleus of the lateral lemniscus

Markovitz, Nancy S.; Pollak, George D.

doi:10.1016/0378-5955(94)90290-9

Cited by 60 publications

(21 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1) Projections from both the ipsilateral and contralateral DNLL are thought to be largely GABAergic and therefore inhibitory (Adams and Mugnaini 1984;Shneiderman et al 1988;Yang and Pollak 1998). 2) Most DNNL neurons are sensitive to binaural cues such as ITD and ILD (Brugge et al 1970;Kelly et al 1998;Markovitz and Pollak 1994), consistent with the directionally dependent suppression found in the IC. 3) DNLL appears to project to all regions of the IC (Shneiderman et al 1988), consistent with our finding that the characteristics of suppression in the IC do not depend much on CF (Fig.…”

Section: Neural Mechanisms Underlying Suppressionmentioning

confidence: 49%

Neural Correlates of the Precedence Effect in the Inferior Colliculus: Effect of Localization Cues

Litovsky

Delgutte

2002

Journal of Neurophysiology

View full text Add to dashboard Cite

Litovsky, R. Y. and B. Delgutte. Neural correlates of the precedence effect in the inferior colliculus: effect of localization cues. J Neurophysiol 87: 976 -994, 2002; 10.1152/jn.00568.2001. The precedence effect (PE) is an auditory phenomenon involved in suppressing the perception of echoes in reverberant environments, and is thought to facilitate accurate localization of sound sources. We investigated physiological correlates of the PE in the inferior colliculus (IC) of anesthetized cats, with a focus on directional mechanisms for this phenomenon. We used a virtual space (VS) technique, where two clicks (a "lead" and a "lag") separated by a brief time delay were each filtered through head-related transfer functions (HRTFs). For nearly all neurons, the response to the lag was suppressed for short delays and recovered at long delays. In general, both the time course and the directional patterns of suppression resembled those reported in freefield studies in many respects, suggesting that our VS simulation contained the essential cues for studying PE phenomena. The relationship between the directionality of the response to the lead and that of its suppressive effect on the lag varied a great deal among IC neurons. For a majority of units, both excitation produced by the lead and suppression of the lag response were highly directional, and the two were similar to one another. For these neurons, the long-lasting inhibitory inputs thought to be responsible for suppression seem to have similar spatial tuning as the inputs that determine the excitatory response to the lead. Further, the behavior of these neurons is consistent with psychophysical observations that the PE is strongest when the lead and the lag originate from neighboring spatial locations. For other neurons, either there was no obvious relationship between the directionality of the excitatory lead response and the directionality of suppression, or the suppression was highly directional whereas the excitation was not, or vice versa. For these neurons, the excitation and the suppression produced by the lead seem to depend on different mechanisms. Manipulation of the directional cues (such as interaural time and level differences) contained in the lead revealed further dissociations between excitation and suppression. Specifically, for about one-third of the neurons, suppression depended on different directional cues than did the response to the lead, even though the directionality of suppression was similar to that of the lead response when all cues were present. This finding suggests that the inhibitory inputs causing suppression may originate in part from subcollicular auditory nuclei processing different directional cues than the inputs that determine the excitatory response to the lead. Neurons showing such dissociations may play an important role in the PE when the lead and the lag originate from very different directions.

show abstract

Section: Neural Mechanisms Underlying Suppressionmentioning

confidence: 49%

Neural Correlates of the Precedence Effect in the Inferior Colliculus: Effect of Localization Cues

Litovsky

Delgutte

2002

Journal of Neurophysiology

View full text Add to dashboard Cite

show abstract

“…Located immediately below the inferior colliculus, it receives innervation from a complement of lower nuclei similar to those that innervate the inferior colliculus, and it sends strong bilateral projections to the central nucleus of the inferior colliculus (ICc; Glendenning et al, 1981;Kudo, 1981;Zook and Casseday, 1982, 1985Ross et a]., 1988;Shneiderman et al, 1988;Ross and Pollak, 1989;Hutson et al, 1991;Bajo et al, 1993;Merchan et al, 1994;Huffman and Covey, 1995;Vater et al, 1995). DNLL neurons are also distinguished by two additional features: 1) They are largely binaural, and those neurons tuned to high frequencies are driven by stimulation of the contralatera1 ear and inhibited by stimulation of the ipsilateral ear Buckthought eta]., 1993; Covey, 1993;Markovitz and Pollak, 1994;Yang and Pollak, 1994a); and 2) they are strongly immunoreactive for antibodies against conjugated y-aminobutyric acid (GABA) or glutamic acid decarboxylase (GAD), the rate-limiting enzyme for the synthesis of GABA (Adams and Mugnaini, 1984;Thompson et al, 1985;Moore and Moore, 1987;Roberts and Ribak, 1987;Glendenning and Baker, 1988;Vater et al, 1992a;Covey, 1993;Vater, 1995;Winer et al, 1995).…”

Section: Indexing Terms: Amplitude Modulation Temporal Discharge Patmentioning

confidence: 97%

Afferent connections to the dorsal nucleus of the lateral lemniscus of the mustache bat: evidence for two functional subdivisions

Yang¹,

Liu²,

Pollak³

1996

J. Comp. Neurol.

Self Cite

View full text Add to dashboard Cite

The dorsal nucleus of the lateral lemniscus (DNLL) of the mustache bat, Pteronotus parnellii, was found to consist of two divisions. The neurons in each division were distinguished by their temporal discharge patterns evoked both by tone bursts and sinusoidal amplitude-modulated (SAM) signals. Neurons in the anterior one-third of the DNLL responded to tone bursts with an onset discharge pattern and only phase-locked to SAM signals with low modulation frequencies (< 300 Hz). Neurons in the posterior two-thirds of the DNLL responded to tone bursts with a sustained discharge pattern and phase-locked to SAM signals with much higher modulation frequencies (400-800 Hz). In addition, there was a different frequency representation in the two divisions. The frequency representation in the posterior division was from about 15 to 120 kHz, whereas in the anterior division it was only up to 62 kHz. The physiological differences were further supported by data from experiments that revealed the sources of afferent projections to the two DNLL divisions. Retrograde labeling showed that the afferent projections to the two divisions were from different neuronal populations. Input differences were of two types. Some nuclei projected to one or the other DNLL division, but not to both. For instance, the ventral nucleus of the lateral lemniscus projected predominately to the anterior DNLL and provided little or no inputs to the posterior DNLL, whereas the medial superior olive innervated the posterior but not the anterior DNLL. Other lower nuclei projected to both DNLL divisions. These include the contralateral cochlear nucleus, the ipsi- and contralateral lateral superior olives, the intermediate nucleus of the lateral lemniscus, and the contralateral DNLL. However, the projections to each division of the DNLL originate from different neuronal subpopulations in each lower nucleus. The functional implications of these findings are discussed in the context of the possible impacts that the two DNLL divisions exert on their postsynaptic targets in the inferior colliculus.

show abstract

“…We first determined the dimensions of the DN L L. The DN L L stains intensely with cytochrome oxidase and stands out clearly from other structures (Markovitz and Pollak, 1994). We processed four brains for cytochrome oxidase and determined the largest rostrocaudal, mediolateral, and dorsoventral extent of the DN L L. On average, the dimensions were as follows: rostrocaudal 554 m, mediolateral 524 m, and dorsoventral 282 m. The histological and other procedures used to determine these dimensions are described below.…”

Section: Methodsmentioning

confidence: 99%

“…The main reason was that we wanted to minimize any potential tissue damage caused by the mechanical deformations that result from the relatively large volumes of liquid injected with pressure. Thus, we wanted to inactivate repeatedly the DN L L and be confident that the previous inactivation had not caused damage to the DN L L.We first determined the dimensions of the DN L L. The DN L L stains intensely with cytochrome oxidase and stands out clearly from other structures (Markovitz and Pollak, 1994). We processed four brains for cytochrome oxidase and determined the largest rostrocaudal, mediolateral, and dorsoventral extent of the DN L L. On average, the dimensions were as follows: rostrocaudal 554 m, mediolateral 524 m, and dorsoventral 282 m. The histological and other procedures used to determine these dimensions are described below.…”

mentioning

confidence: 99%

Reversible Inactivation of the Dorsal Nucleus of the Lateral Lemniscus Reveals Its Role in the Processing of Multiple Sound Sources in the Inferior Colliculus of Bats

2001

Self Cite

View full text Add to dashboard Cite

Neurons in the inferior colliculus (IC) that are excited by one ear and inhibited by the other [excitatory-inhibitory (EI) neurons] can code interaural intensity disparities (IIDs), the cues animals use to localize high frequencies. Although EI properties are first formed in a lower nucleus and imposed on some IC cells via an excitatory projection, many other EI neurons are formed de novo in the IC. By reversibly inactivating the dorsal nucleus of the lateral lemniscus (DNLL) in Mexican free-tailed bats with kynurenic acid, we show that the EI properties of many IC cells are formed de novo via an inhibitory projection from the DNLL on the opposite side. We also show that signals excitatory to the IC evoke an inhibition in the opposite DNLL that persists for tens of milliseconds after the signal has ended. During that period, strongly suppressed EI cells in the IC are deprived of inhibition from the DNLL and respond to binaural signals as weakly inhibited or monaural cells. By relieving inhibition at the IC, we show that an initial binaural signal essentially reconfigures the circuit and thereby allows IC cells to respond to trailing binaural signals that were inhibitory when presented alone. Thus, DNLL innervation creates a property in the IC that is not possessed by lower neurons or by collicular EI neurons that are not innervated by the DNLL. That property is a change in responsiveness to binaural signals, a change dependent on the reception of an earlier sound. These features suggest that the circuitry linking the DNLL with the opposite central nucleus of the IC is important for the processing of IIDs that change over time, such as the IIDs generated by moving stimuli or by multiple sound sources that emanate from different regions of space. Key words: GABA; persistent inhibition; precedence effect; inferior colliculus; sound localization; dorsal nucleus of lateral lemniscusThe projections from the vast majority of lower auditory nuclei converge at a common destination in the central nucleus of the inferior colliculus (ICc) (for review, see Aitkin, 1986;Oliver and Huerta, 1992). This large convergence of inputs suggests that substantial transformations occur in the ICc; yet the response properties of ICc neurons appear to be similar to those of the lower nuclei from which they receive their innervation. An example is excitatory-inhibitory (EI) neurons in the ICc, neurons that are excited by one ear and inhibited by the other ear. These neurons are sensitive to interaural intensity disparities (IIDs), the cues animals use to localize high-frequency sounds (Erulkar, 1972;Mills, 1972). EI neurons are initially formed in the lateral superior olive (LSO) (Boudreau and Tsuchitani, 1968;Finlayson and Caspary, 1991). They are also the dominant type in the dorsal nucleus of the lateral lemniscus (DNLL), a nucleus the neurons of which are almost exclusively GABAergic (Brugge et al., 1970;Adams and Mugniani, 1984;Covey, 1993; Yang and Pollak, 1994a,b,c;Winer et al., 1995). The DNLL, like the ICc, is one of the principa...

show abstract

Binaural processing in the dorsal nucleus of the lateral lemniscus

Cited by 60 publications

References 60 publications

Neural Correlates of the Precedence Effect in the Inferior Colliculus: Effect of Localization Cues

Neural Correlates of the Precedence Effect in the Inferior Colliculus: Effect of Localization Cues

Afferent connections to the dorsal nucleus of the lateral lemniscus of the mustache bat: evidence for two functional subdivisions

Reversible Inactivation of the Dorsal Nucleus of the Lateral Lemniscus Reveals Its Role in the Processing of Multiple Sound Sources in the Inferior Colliculus of Bats

Contact Info

Product

Resources

About