The Journal of Neuroscience, October 1, 2001, 21(19):7848-7858
Proprioceptive Information from the Pinna Provides Somatosensory
Input to Cat Dorsal Cochlear Nucleus
Patrick O.
Kanold and
Eric D.
Young
The Center for Hearing Sciences and Department of Biomedical
Engineering, The Johns Hopkins University School of Medicine,
Baltimore, Maryland 21205
The dorsal cochlear nucleus (DCN) is a second-order auditory
structure that also receives nonauditory information, including somatosensory inputs from the dorsal column and spinal trigeminal nuclei. Here we investigate the peripheral sources of the somatosensory inputs to DCN. Electrical stimulation was applied to cervical nerves
C1-C8, branches of C2, branches of the trigeminal nerve, and hindlimb
nerves. The largest evoked potentials in the DCN were produced by C2
stimulation and by stimulation of its branches that innervate the
pinna. Electrical stimulation of C2 produced a pattern of inhibition
and excitation of DCN principal cells comparable with that seen in
previous studies with stimulation of the primary somatosensory nuclei,
suggesting that the same pathway was activated. Because C2 contains
both proprioceptive and cutaneous fibers, we applied peripheral
somatosensory stimulation to identify the effective somatosensory
modalities. Only stimuli that activate pinna muscle receptors, such as
stretch or vibration of the muscles connected to the pinna, were
effective in driving DCN units, whereas cutaneous stimuli such as light
touch, brushing of hairs, and stretching of skin were ineffective.
These results suggest that the largest somatosensory inputs to the DCN
originate from muscle receptors associated with the pinna. They support the hypothesis that a role of the DCN in hearing is to coordinate pinna
orientation to sounds or to support correction for the effects of pinna
orientation on sound-localization cues.
Key words:
auditory; somatosensory; dorsal cochlear nucleus; cat; pinna; multisensory; sound localization
Copyright © 2001 Society for Neuroscience 0270-6474/01/21197848-11$05.00/0
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