John R. Doucet

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Local circuit interactions between the dorsal and ventral divisions of the cochlear nucleus are known to influence the evoked responses of the resident neurons to sound. In the present study, we examined the projections of neurons in the ventral cochlear nucleus to the dorsal cochlear nucleus by using retrograde transport of biotinylated dextran amine(More)
Certain distinct populations of neurons in the dorsal cochlear nucleus are inhibited by a neural source that is responsive to a wide range of acoustic frequencies. In this study, we examined the glycine immunoreactivity of two types of ventral cochlear nucleus neurons (planar and radiate) in the rat which project to the dorsal cochlear nucleus (DCN) and(More)
The integration of information across sensory modalities enables sound to be processed in the context of position, movement, and object identity. Inputs to the granule cell domain (GCD) of the cochlear nucleus have been shown to arise from somatosensory brain stem structures, but the nature of the projection from the spinal trigeminal nucleus is unknown. In(More)
Multipolar cells in the ventral cochlear nucleus (VCN) are a structurally and functionally diverse group of projection neurons. Understanding their role in the ascending pathway involves partitioning multipolar cells into distinct populations and determining where in the brain each sends its coded messages. In this study, we used retrograde labeling(More)
Corticofugal pathways originating in auditory cortex innervate most subcortical auditory nuclei in the ascending pathway [Auditory Neurosci. 1 (1995) 287-308; J. Comp. Neurol. 371 (1996) 15-40]. Our goal is to determine if these projections arise from the same neurons or if different neurons project to each of the separate structures. We also seek to(More)
The lateral superior olive (LSO) contains cells that are sensitive to intensity differences between the two ears, a feature used by the brain to localize sounds in space. This report describes a source of input to the LSO that complements bushy cell projections from the ventral cochlear nucleus (VCN). Injections of biotinylated dextran amine (BDA) into the(More)
Cortical area Te1 in the rat commonly is associated with primary auditory cortex. It is the source of direct projections to the inferior colliculus (IC), superior olivary complex (SOC), and the cochlear nucleus (CN). A question that arises is whether these descending pathways derive from a common source or separate populations of cortical neurons. We(More)
There is growing evidence that hearing involves the integration of many brain functions, including vision, balance, somatic sensation, learning and memory, and emotional state. Some of these integrative processes begin at the earliest stages of the central auditory system. In this review, we will discuss evidence that reveals multimodal projections into the(More)
Synaptic inputs from one cochlear nucleus (CN) to the other can play an important role in modulating the activity of CN neurons. Using the isolated whole brain preparation of the guinea pig, we tested the effects of electrical stimulation of the contralateral auditory nerve (AN) on intracellularly recorded and stained neurons of the anteroventral cochlear(More)
Commissural neurons connect the cochlear nucleus complexes of both ears. Previous studies have suggested that the neurons may be separated into two anatomical subtypes on the basis of percent apposition (PA); that is, the percentage of the soma apposed by synaptic terminals. The present study combined tract tracing with synaptic immunolabeling to compare(More)