An in vivo intraneuronal recording/HorseRadish Peroxidase marking study of the dorsal (DCN) and posteroventral (PVCN) cochlear nucleus (CN) is proposed. We will ascertain acoustic and electrotonic response properties of CN neurons in the gerbil. Both anesthetized and unanesthetized, decerebrate preparations will be systematically studied because anesthesia is known to influence unit responses. The morphology of labeled neurons will be characterized according to location, and dendritic and axonal branching patterns for assignment to an anatomically-based neuronal type. Evidence from this laboratory suggests functional interactions between specific classes of units within the DCN. Recent in vitro evidence suggests interaction between neurons of the DCN and PVCN. In order to fully evaluate such interactions in the context of a functioning auditory system, the proposed in vivo studies will directly correlate anatomical neuron type with response properties. We hypothesize that the use of extensive response characteristics (e.g. response maps, noise responses, membrane time constants, etc.), enabled by computerization, will provide unequivocal correlations between unit and neuron types. Although past efforts at such correlations have proven equivocal, the present effort should prove successful because 1.) the preparation is very stable and 2.) correlation is not solely or primarily based on the peristimulus time histogram scheme, rather it will be based on a constellation of response characteristics. Thus the objective within the frame of the present proposal is to discover structure/function relationships in the DCN and PVCN, and to evaluate effects of anesthesia on the CN and, by analogy, other neural systems. Our ultimate goal is to elucidate CN neuronal circuitry, including membrane properties and neural interactions. Mechanisms by which the CN subnuclei play an integrative role in hearing may thus be understood and incorporated into schemes of auditory prostheses.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC001099-02
Application #
3217824
Study Section
Hearing Research Study Section (HAR)
Project Start
1991-04-01
Project End
1995-03-31
Budget Start
1992-04-01
Budget End
1993-03-31
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Boston University
Department
Type
Schools of Engineering
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Navawongse, Rapeechai; Voigt, Herbert F (2009) Single neuron recordings in dorsal cochlear nucleus (DCN) of awake gerbil. Hear Res 255:44-57
Hancock, Kenneth E; Voigt, Herbert F (2002) Intracellularly labeled fusiform cells in dorsal cochlear nucleus of the gerbil. II. Comparison of physiology and anatomy. J Neurophysiol 87:2520-30
Hancock, Kenneth E; Voigt, Herbert F (2002) Intracellularly labeled fusiform cells in dorsal cochlear nucleus of the gerbil. I. Physiological response properties. J Neurophysiol 87:2505-19
Ding, J; Benson, T E; Voigt, H F (1999) Acoustic and current-pulse responses of identified neurons in the dorsal cochlear nucleus of unanesthetized, decerebrate gerbils. J Neurophysiol 82:3434-57
Davis, K A; Voigt, H F (1997) Evidence of stimulus-dependent correlated activity in the dorsal cochlear nucleus of decerebrate gerbils. J Neurophysiol 78:229-47
Ding, J; Voigt, H F (1997) Intracellular response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil. J Neurophysiol 77:2549-72
Gdowski, G T; Voigt, H F (1997) Response map properties of units in the dorsal cochlear nucleus of barbiturate-anesthetized gerbil (Meriones unguiculatus). Hear Res 105:85-104
Ravicz, M E; Rosowski, J J; Voigt, H F (1996) Sound-power collection by the auditory periphery of the mongolian gerbil Meriones unguiculatus. II. External-ear radiation impedance and power collection. J Acoust Soc Am 99:3044-63
Davis, K A; Ding, J; Benson, T E et al. (1996) Response properties of units in the dorsal cochlear nucleus of unanesthetized decerebrate gerbil. J Neurophysiol 75:1411-31
Davis, K A; Voigt, H F (1996) Computer simulation of shared input among projection neurons in the dorsal cochlear nucleus. Biol Cybern 74:413-25

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