Spatial map of frequency tuning-curve shapes in the mouse inferior colliculus

Ehret, Günter; Егорова, М. А.; Hage, Steffen R.; Müller, Birgit A.

doi:10.1097/00001756-200307180-00017

Cited by 28 publications

(31 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An important challenge in understanding the organization of the IC is discovering what is represented over the surface of a frequency-band lamina, i.e., in the plane orthogonal to the tonotopic axis. Evidence exists for a shallow gradient in best frequency across the laminae (Langner and Schreiner,1988; Malmierca et al,2008; Merzenich and Reid,1974), and other stimulus features have also been reported to be mapped over their surface, including modulation frequency periodotopy (Langner and Schreiner,1988; Schreiner and Langner,1988), selectivity for rate of change of frequency (Ehret et al,2003; Hage and Ehret,2003), and unit threshold and bandwidth of frequency tuning (Schreiner and Langner,1988; for reviews see Ehret and Schreiner,2005; Rees and Langner,2005). The divergent pattern of connections we have observed could be a means by which the integration of responses across such parameter representations is affected.…”

Section: Discussionmentioning

confidence: 99%

Divergent and point‐to‐point connections in the commissural pathway between the inferior colliculi

Malmierca

Hernández

Antunes

et al. 2009

J of Comparative Neurology

View full text Add to dashboard Cite

The commissure of the inferior colliculus interconnects the left and right sides of the auditory midbrain and provides the final opportunity for interaction between the two sides of the auditory pathway at the subcortical level. Although the functional properties of the commissure are beginning to be revealed, the topographical organization of its connections is unknown. A combination of neuroanatomical tracing studies, 3D reconstruction, and neuronal density maps was used to study the commissural connections in rat. The results demonstrate that commissural neurons in the central nucleus of the inferior colliculus send a divergent projection to the equivalent frequency-band laminae in the central nucleus and dorsal and lateral cortices on the opposite side. The density of this projection, however, is weighted toward a point that matches the position of the tracer injection; consistent with a point-to-point emphasis in the wiring pattern. In the dorsal cortex of the inferior colliculus there may be two populations of neurons that project across the commissure, one projecting exclusively to the frequency-band laminae in the central nucleus and the other projecting diffusely to the dorsal cortex. Neurons in the lateral cortex of the inferior colliculus make only a very weak contribution to the commissural pathway. The point-to-point pattern of connections permits interactions between specific regions of corresponding frequency-band laminae, whereas the divergent projection pattern could subserve integration across the lamina. J. Comp. Neurol. 514:226–239, 2009. © 2009 Wiley-Liss, Inc.

show abstract

Section: Discussionmentioning

confidence: 99%

Divergent and point‐to‐point connections in the commissural pathway between the inferior colliculi

Malmierca

Hernández

Antunes

et al. 2009

J of Comparative Neurology

View full text Add to dashboard Cite

show abstract

“…3C and D). In the mouse IC, tuning curve shapes have been classified as broadly tuned on the low frequency side and sharply tuned on the high frequency side (class I), sharply tuned on both sides (class II), broadly tuned (classic V-shape, class III) or complexly tuned with multiple regions of excitation (class IV) (Egorova et al, 2001; Ehret et al, 2003). Class II and III tend to be most prevalent (~30 % each) (Egorova et al, 2001; Portfors et al, 2011).…”

Section: General Features Of Auditory Processing In Ic and Mldmentioning

confidence: 99%

Conserved mechanisms of vocalization coding in mammalian and songbird auditory midbrain

Woolley

Portfors

2013

Hearing Research

View full text Add to dashboard Cite

The ubiquity of social vocalization among animals provides the opportunity to identify conserved mechanisms of auditory processing that subserve vocal communication. Identifying auditory coding properties that are shared across vocal communicators will provide insight into how human auditory processing leads to speech perception. Here, we compare auditory response properties and neural coding of social vocalizations in auditory midbrain neurons of mammalian and avian vocal communicators. The auditory midbrain is a nexus of auditory processing because it receives and integrates information from multiple parallel pathways and provides the ascending auditory input to the thalamus. The auditory midbrain is also the first region in the ascending auditory system where neurons show complex tuning properties that are correlated with the acoustics of social vocalizations. Single unit studies in mice, bats and zebra finches reveal shared principles of auditory coding including tonotopy, excitatory and inhibitory interactions that shape responses to vocal signals, nonlinear response properties that are important for auditory coding of social vocalizations and modulation tuning. Additionally, single neuron responses in the mouse and songbird midbrain are reliable, selective for specific syllables, and rely on spike timing for neural discrimination of distinct vocalizations. We propose that future research on auditory coding of vocalizations in mouse and songbird midbrain neurons adopt similar experimental and analytical approaches so that conserved principles of vocalization coding may be distinguished from those that are specialized for each species.

show abstract

“…Within the frequency laminae of the IC there exist secondary spatial gradients in response properties, including a gradient in the limited range of frequencies contained in a single lamina that is orthogonal to the main frequency axis in the IC (Schreiner and Langner 1997). In addition to a gradient in CFs, there are gradients in other types of response properties including the pattern of the spike train, the shape of the frequency tuning curve, selectivity for FM sweeps, or the degree to which binaural responsiveness is shaped by ipsilateral inhibition (Wenstrup et al 1985(Wenstrup et al ,1986Bruckner and Rubsamen 1995;Hage and Ehret 2003;Ehret et al 2003). Because we did not measure these response properties in the current study, we cannot evaluate whether fenfluramine selectively increases the latencies of these types of neurons, but these possibilities can be tested in the future.…”

Section: A Difference In the Effects Of Fenfluramine Versus Serotoninmentioning

confidence: 99%

The serotonin releaser fenfluramine alters the auditory responses of inferior colliculus neurons

Hall

Hurley

2007

Hearing Research

View full text Add to dashboard Cite

Local direct application of the neuromodulator serotonin strongly influences auditory response properties of neurons in the inferior colliculus (IC), but endogenous stores of serotonin may be released in a distinct spatial or temporal pattern. To explore this issue, the serotonin releaser fenfluramine was iontophoretically applied to extracellularly recorded neurons in the IC of the Mexican free-tailed bat (Tadarida brasiliensis). Fenfluramine mimicked the effects of serotonin on spike count and first spike latency in most neurons, and its effects could be blocked by co-application of serotonin receptor antagonists, consistent with fenfluramine-evoked serotonin release. Responses to fenfluramine did not vary during single applications or across multiple applications, suggesting that fenfluramine did not deplete serotonin stores. A predicted gradient in the effects of fenfluramine with serotonin fiber density was not observed, but neurons with fenfluramine-evoked increases in latency occurred at relatively greater recording depths compared to other neurons with similar characteristic frequencies. These findings support the conclusion that there may be spatial differences in the effects of exogenous and endogenous sources of serotonin, but that other factors such as the identities and locations of serotonin receptors are also likely to play a role in determining the dynamics of serotonergic effects.

show abstract

Spatial map of frequency tuning-curve shapes in the mouse inferior colliculus

Cited by 28 publications

References 9 publications

Divergent and point‐to‐point connections in the commissural pathway between the inferior colliculi

Divergent and point‐to‐point connections in the commissural pathway between the inferior colliculi

Conserved mechanisms of vocalization coding in mammalian and songbird auditory midbrain

The serotonin releaser fenfluramine alters the auditory responses of inferior colliculus neurons

Contact Info

Product

Resources

About