Dendritic orientation and laminar architecture in the rabbit auditory thalamus

Cetas, Justin S.; Price, Robin O.; Crowe, Jennifer J.; Velenovsky, David S.; McMullen, Nathaniel T.

doi:10.1002/cne.10595

Cited by 17 publications

(14 citation statements)

References 54 publications

(98 reference statements)

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“…6), the injection focus extends vertically across the MGV laminas. Such an injection would be expected to cross multiple frequency slabs in this species (Cetas et al, 2002b).…”

Section: Resultsmentioning

confidence: 99%

“…(2) More importantly, experimental animals served as their own controls; adjacent cortical penetrations in which one electrode passed through a TC patch while the other did not were comparable in frequency progression, latency, sharpness of tuning, and response strength. (3) In some cases, the multi-unit responses within a TC patch (Cetas et al, , 2002a(Cetas et al, , 2002b. TC axons originating from binaural-specific relay neurons (red, blue) located in frequency slabs terminate in patches along a frequency strip in AI.…”

Section: Integrity Of Tracer-injected Mgvmentioning

confidence: 99%

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Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

et al. 2003

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Several functional maps have been described in primary auditory cortex, including those related to frequency, tuning, latency, binaurality, and intensity. Many of these maps are arranged in a discontinuous or patchy manner. Similarly, thalamocortical projections arising from the ventral division of the medial geniculate body to the primary auditory cortex are also patchy. We used anterograde labeling and electrophysiological methods to examine the relationship between thalamocortical patches and auditory cortical maps. Biotinylated dextran-amine was deposited into physiologically characterized sites in the ventral division of the medial geniculate body of New Zealand white rabbits. Approximately 7 d later, the animal was again anesthetized and the ipsilateral auditory cortex was mapped with tungsten microelectrodes. Multi-unit physiological data were obtained for the following characteristics: best frequency (BF), binaurality, response type, latency, sharpness of tuning, and threshold. Immunocytochemical methods were used to reveal the injection site in the ventral division of the medial geniculate body as well as the anterogradely labeled thalamocortical afferents in the auditory cortex. In 86% of the cases (12 of 14), entry into a thalamocortical patch was associated with a marked change in physiological responses. A consistent BF and binaural class were usually observed within a patch. The patches appear to innervate distinct functional regions coding frequency and binaurality. A model is presented showing how patchy thalamocortical projections participate in the formation of tonotopic and binaural maps in primary auditory cortex.

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“…6), the injection focus extends vertically across the MGV laminas. Such an injection would be expected to cross multiple frequency slabs in this species (Cetas et al, 2002b).…”

Section: Resultsmentioning

confidence: 99%

Section: Integrity Of Tracer-injected Mgvmentioning

confidence: 99%

Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

et al. 2003

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“…Previous studies in cat and rabbit found a single low-to-high BF organization or tonotopy in MGBv (Aitkin and Webster, 1972;Imig and Morel, 1985;Brandner and Redies, 1990;Cetas et al, 2002;Cetas et al, 2003). Neurons with similar BFs form isofrequency laminae which extend ~3 mm in the dorsal-ventral dimension of MGBv in both species and which correspond anatomically to fibrodendritic laminae (Morest, 1965).…”

Section: Abstract Auditory Cortex; Medial Geniculate Body; Thalamus; mentioning

confidence: 91%

“…MGBv neurons in turn project to AI, where these features are represented in layer III and layer IV (Read et al, 2002), forming a two dimensional projection plane (Huang and Winer, 2000;Smith and Populin, 2001). Previous studies in cat and rabbit found a single low-to-high BF organization or tonotopy in MGBv (Aitkin and Webster, 1972;Imig and Morel, 1985;Brandner and Redies, 1990;Cetas et al, 2002;Cetas et al, 2003). Neurons with similar BFs form isofrequency laminae which extend ~3 mm in the dorsal-ventral dimension of MGBv in both species and which correspond anatomically to fibrodendritic laminae (Morest, 1965).…”

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confidence: 91%

Two thalamic pathways to primary auditory cortex

Read¹,

Miller²,

Schreiner³

et al. 2008

Neuroscience

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Neurons in the center of cat primary auditory cortex (AI) respond to a narrow range of sound frequencies and the preferred frequencies in local neuron clusters are closely aligned in this central narrow bandwidth region (cNB). Response preferences to other input parameters, such as sound intensity and binaural interaction, vary within cNB; however, the source of this variability is unknown. Here we examined whether input to the cNB could arise from multiple, anatomically independent subregions in the ventral nucleus of the medial geniculate body (MGBv). Retrograde tracers injected into cNB labeled discontinuous clusters of MGBv neurons in the superior and inferior MGBv (sMGBv, iMGBv). Most labeled neurons were in the sMGBv and their density was greater. iMGBv somata were significantly larger. These findings suggest that cNB projection neurons in superior and inferior MGBv have distinct anatomic and possibly physiologic organization. Keywords auditory cortex; medial geniculate body; thalamus; parallel pathwaysThe auditory thalamus is an obligatory station in the pathway from peripheral receptors to auditory cortex . The ventral division of the medial geniculate body (MGBv) is the source of >75% of ascending sensory input to the primary auditory cortex (AI) (Middlebrooks and Zook, 1983;Lee and Winer, 2005). Best frequency and frequency bandwidth properties are organized topographically in the three dimensions of the MGBv (Rouiller and de Ribaupierre, 1985). MGBv neurons in turn project to AI, where these features are represented in layer III and layer IV (Read et al., 2002), forming a two dimensional projection plane (Huang and Winer, 2000;Smith and Populin, 2001).Previous studies in cat and rabbit found a single low-to-high BF organization or tonotopy in MGBv (Aitkin and Webster, 1972;Imig and Morel, 1985;Brandner and Redies, 1990;Cetas et al., 2002;Cetas et al., 2003). Neurons with similar BFs form isofrequency laminae which extend ~3 mm in the dorsal-ventral dimension of MGBv in both species and which correspond anatomically to fibrodendritic laminae (Morest, 1965). The BFs of neighboring laminae differ *Corresponding author. Tel/fax: +1-860-486-4895/+1-860-377-7987 E-mail address: E-mail: heather.read@uconn.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. (Imig and Morel, 1985) or up to 1 octave in rabbit (Cetas et al., 2001;Cetas et al., 2002) MGBv. Reconstruction of physiological recording tracks in cat MGBv (Imig and Morel, 1985) suggests two distinct regions within the laminar subdivision, one with a fine and the other with a coarser tonotopic frequency...

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“…Besides possible species differences, this discrepancy might be attributable to different organizations in MGV and IC. A comparison of dendritic fields suggests that the larger step size is positively correlated with a larger dendritic field width (Cetas et al, 2003).…”

Section: Relationship Of Tonotopic Organization To Anatomymentioning

confidence: 99%

A Discontinuous Tonotopic Organization in the Inferior Colliculus of the Rat

et al. 2008

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Audible frequencies of sound are encoded in a continuous manner along the length of the cochlea, and frequency is transmitted to the brain as a representation of place on the basilar membrane. The resulting tonotopic map has been assumed to be a continuous smooth progression from low to high frequency throughout the central auditory system. Here, physiological and anatomical data show that best frequency is represented in a discontinuous manner in the inferior colliculus, the major auditory structure of the midbrain. Multiunit maps demonstrate a distinct stepwise organization in the order of best frequency progression. Furthermore, independent data from single neurons show that best frequencies at octave intervals of approximately one-third are more prevalent than others. These data suggest that, in the inferior colliculus, there is a defined space of tissue devoted to a given frequency, and input within this frequency band may be pooled for higher-level processing.

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Dendritic orientation and laminar architecture in the rabbit auditory thalamus

Cited by 17 publications

References 54 publications

Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

Functional Subregions in Primary Auditory Cortex Defined by Thalamocortical Terminal Arbors: An Electrophysiological and Anterograde Labeling Study

Two thalamic pathways to primary auditory cortex

A Discontinuous Tonotopic Organization in the Inferior Colliculus of the Rat

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