Ascending projections from the nucleus of the brachium of the inferior colliculus in the cat

Kudo, Motoi; Tashiro, Takashi; Higo, Shigeyoshi; Matsuyama, Tomoo; Kawamura, Syosuke

doi:10.1007/bf00236219

Cited by 58 publications

(46 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast, Edwards et al (1979) reported that, in the cat, the BIN projects only to the contralateral SC. This finding is inconsistent with the results of the present study as well as those of other previous tracing studies carried out on a range of species, including cats (van Buskirk, 1983;Kudo et al, 1984;Wallace and Fredens, 1989), and may reflect a difference in the criteria used for defining the borders of the BIN. These anatomical studies are supported by evidence for a functional connection between the IC and the SC.…”

Section: Auditory Inputs To the Superior Colliculuscontrasting

confidence: 82%

“…Some of these studies did not identify which regions of the IC provide the SC afferents (Moore and Goldberg, 1966;Tarlov and Moore, 1966;Powell and Hatton, 1969;Cadusseau and Roger, 1985), whereas others reported SC inputs originating in the BIN (Edwards et al, 1979;van Buskirk, 1983;Kudo et al, 1984;Wallace and Fredens, 1989), ICX (Edwards et al, 1979;Kudo and Niimi, 1980;van Buskirk, 1983;Hashikawa and Kawamura, 1983;Druga and Syka, 1984;Covey et al, 1987;Zhang et al, 1987), ICP (Edwards et al, 1979;Hashikawa and Kawamura, 1983), and ICC (Druga and Syka, 1984;Covey et al, 1987;Zhang et al, 1987). The majority of these studies described inputs either predominantly or exclusively from regions of the ipsilateral IC.…”

Section: Auditory Inputs To the Superior Colliculusmentioning

confidence: 91%

See 1 more Smart Citation

Auditory brainstem projections to the ferret superior colliculus: Anatomical contribution to the neural coding of sound azimuth

1998

View full text Add to dashboard Cite

The mammalian superior colliculus (SC) contains a neural map of auditory space. It is not known whether this topographic representation emerges at the level of the SC or is relayed there from other auditory areas. We have used retrograde labelling techniques in ferrets to examine the sources and pattern of innervation from auditory brainstem nuclei. After multiple injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the SC, the heaviest concentrations of labelled cells were found in the nucleus of the brachium (BIN) and external nucleus of the inferior colliculus, with much weaker labelling in the nucleus sagulum, dorsal, intermediate and ventral nuclei of the lateral lemniscus, paralemniscal regions, and periolivary nuclei. The projections were predominantly ipsilateral, although labelled cells were found on both sides of the brainstem. Single injections of WGA-HRP or discrete injections of red and green latex microspheres revealed that the caudal and lateral regions of the SC receive the heaviest projections, although the majority of the retrogradely labelled neurons in the contralateral BIN project to rostral SC. On the ipsilateral side, neurons in rostral and caudal regions of the BIN were labelled primarily by the tracer injected into rostral and caudal regions of the SC, respectively. However, no clear segregation was apparent in the BIN after injections into the medial and lateral regions or in any of the other nuclei after either injection paradigm. These data suggest that converging inputs from several auditory brainstem nuclei contribute to the construction of the auditory space map in the SC, although information about sound azimuth may be conveyed to this nucleus via a spatially ordered projection from the ipsilateral BIN.

show abstract

Section: Auditory Inputs To the Superior Colliculuscontrasting

confidence: 82%

Section: Auditory Inputs To the Superior Colliculusmentioning

confidence: 91%

Auditory brainstem projections to the ferret superior colliculus: Anatomical contribution to the neural coding of sound azimuth

1998

View full text Add to dashboard Cite

show abstract

“…In the nucleus of the BIC, the percentage of projection neurons with GABA-positive immunoreactivity was small. The weak projection to the dorsal MGB and the absence of a projection to the ventral MGB (Kudo et al, 1984) make the nucleus of the brachium an unlikely source of our observed inhibitory synaptic events. The reticular formation (including the cuneiform nucleus) also had projection neurons to the MGB; however, the vast majority of the projection neurons did not contain GABA.…”

Section: Sources Of the Gabaergic Inhibition In The Mgbmentioning

confidence: 85%

A Monosynaptic GABAergic Input from the Inferior Colliculus to the Medial Geniculate Body in Rat

et al. 1997

View full text Add to dashboard Cite

The goal was to investigate possible monosynaptic GABAergic projections from the inferior colliculus (IC) to thalamocortical neurons of the medial geniculate body (MGB) in the rat. Although there is little evidence for such a projection in other sensory thalamic nuclei, a GABAergic, ascending auditory projection was reported recently in the cat. In the present study, immunohistochemical and tract-tracing methods were used to identify neurons in the IC that contain GABA and project to the MGB. GABA-positive projection neurons were most numerous in the central nucleus and less so in the dorsal and lateral cortex. They were rare in the lateral tegmental system and brachium of the IC. The dorsal nucleus of the lateral lemniscus also contained GABA-positive projection neurons. In brain slices, stimulation of the brachium produced monosynaptic inhibitory postsynaptic potentials in morphologically identified thalamocortical relay neurons. The inhibitory potentials cannot originate locally, because they persisted when ionotropic glutamatergic transmission was blocked. Typically, brachium stimulation elicited a GABA A -mediated inhibitory potential followed by an excitatory potential and a longer latency GABA Bmediated inhibitory potential.We conclude that the GABA-containing neurons of the IC make short-latency, monosynaptic inputs to the thalamocortical projection neurons in the MGB. Such inputs may distinguish the main auditory pathway from indirect or tegmental auditory pathways as well as from other sensory systems. Monosynaptic inhibitory inputs to the medial geniculate may be important for the regulation of firing patterns in thalamocortical neurons. Key words: auditory pathway; retrograde tracing; brain slice preparation; immunohistochemistry; thalamus; midbrain; reticular formation; dorsal nucleus of the lateral lemniscusRecently, a novel and strong GABA-positive input from the inferior colliculus (IC) has been demonstrated in the cat medial geniculate body (MGB) . Thus, thalamocortical neurons in the MGB may receive monosynaptic, GABA-mediated inputs from the brainstem, in contrast to the neurons of other sensory thalamic nuclei. In most thalamic nuclei, inhibitory inputs come from local interneurons or intrathalamic neurons (for review, see Sherman and Koch, 1986;Steriade and Llinas, 1988). For example, in the lateral geniculate body, ascending inputs can excite directly the interneurons, which in turn inhibit thalamocortical neurons (Hirsch and Burnod, 1987;Lindstrom and Wrobel, 1990;Soltesz and Crunelli, 1992;Pape and McCormick, 1995). Such a scenario is less likely in the rat MGB. There are few local GABAergic interneurons, yet many GABA-positive axonal boutons are present Larue, 1988, 1996). This suggests that inhibitory influences arise outside the MGB. Our goal in this study was to identify and characterize one such inhibitory input in the rat.To test whether thalamocortical neurons of the MGB receive monosynaptic GABAergic input from the lower brainstem, we used both anatomical and electrophysiological...

show abstract

“…Indeed, the PO receives auditory inputs from the external, pericentral, and brachial nuclei of the inferior colliculus (Kudo and Niimi, 1980;Kudo et al, 1984;Linke et al, 2000) as well as the dorsal nucleus of the lateral lemniscus (Kudo et al, 1983). In addition, PO receives visual and somatosensory inputs from the superior colliculus and spinal cord (for review, see Jones, 1985).…”

Section: Introductionmentioning

confidence: 99%

Activity-Dependent Synaptic Plasticity in the Central Nucleus of the Amygdala

Samson

Paré

2005

J. Neurosci.

View full text Add to dashboard Cite

Much evidence indicates that fear conditioning involves potentiation of some thalamic inputs to the lateral amygdala (LA). In turn, the LA would excite more neurons in the central nucleus (CE), leading to the generation of fear responses via their brainstem and hypothalamic projections. However, the posterior thalamus not only projects to LA but also to the medial sector of CE (CEm), suggesting that CEm might also be a site of plasticity. To test whether CEm also exhibits activity-dependent synaptic plasticity, we performed whole-cell recordings of CEm neurons in amygdala slices and stimulated thalamic axons coursing through the internal capsule and, as a control, the basolateral (BL) nucleus. High-frequency stimulation of thalamic inputs led to a long-lasting potentiation of thalamic responses, whereas BL-evoked responses remained unchanged. This thalamic long-term potentiation (LTP) developed even when slices were prepared with a cut severing the connections between the LA and CEm but was greatly reduced when an NMDA receptor antagonist was added to the perfusate shortly before and during LTP induction. Yet, intracellular dialysis with the NMDA receptor antagonist (ϩ)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate did not prevent induction of the thalamic LTP, suggesting that presynaptic NMDA receptors are required for its induction. Consistent with this, the thalamic LTP also developed when the cells were dialyzed with a calcium chelator or kept hyperpolarized during induction. Finally, this thalamic LTP was associated with reduced amounts of paired-pulse facilitation, suggesting that it is expressed presynaptically. These results are consistent with the idea that the CEm plays an active role in fear conditioning.

show abstract

Ascending projections from the nucleus of the brachium of the inferior colliculus in the cat

Cited by 58 publications

References 23 publications

Auditory brainstem projections to the ferret superior colliculus: Anatomical contribution to the neural coding of sound azimuth

Auditory brainstem projections to the ferret superior colliculus: Anatomical contribution to the neural coding of sound azimuth

A Monosynaptic GABAergic Input from the Inferior Colliculus to the Medial Geniculate Body in Rat

Activity-Dependent Synaptic Plasticity in the Central Nucleus of the Amygdala

Contact Info

Product

Resources

About