The long-term goal of this project is to understand how the properties of dendrites and circuits influence the integration of pheromone-evoked activity in the mammalian accessory olfactory system. Integration of synaptic inputs arriving at thousands of sites across the dendritic tree is a basic mechanism that influences the functional properties of all neuronal types. In particular types of neurons the mechanisms of synaptic integration are thought to be highly specialized to process certain types of inputs, for example to detect short time delays in the auditory system. The dendritic trees of accessory olfactory bulb (AOB) mitral cells have a complicated and highly specialized morphology. These cells seem to be designed to sample inputs arriving at multiple locations (glomeruli), and then to convey some information about this activity to the mitral cell soma from which it can be passed on to higher brain areas. We propose to use physiological and computational techniques to improve our understanding of synaptic integration in the cells and circuits of the accessory olfactory bulb. In particular we will examine the influence of active and passive properties of AOB mitral cell dendrites on the propagation of synaptic activity from the tufts to the somata of these cells. We also will examine how inputs to multiple tufts are integrated, and determine how activity at one tuft is influenced by signals arriving at other tufts. Overall the experiments proposed will provide increased understanding of many basic issues of synaptic and dendritic processing in neurons, and in particular they will provide valuable information on the integration of chemosensory information in the accessory olfactory system. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21DC006631-02
Application #
6867333
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Davis, Barry
Project Start
2004-03-05
Project End
2007-02-28
Budget Start
2005-03-01
Budget End
2007-02-28
Support Year
2
Fiscal Year
2005
Total Cost
$163,963
Indirect Cost
Name
Carnegie-Mellon University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
052184116
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Hovis, Kenneth R; Ramnath, Rohit; Dahlen, Jeffrey E et al. (2012) Activity regulates functional connectivity from the vomeronasal organ to the accessory olfactory bulb. J Neurosci 32:7907-16
Castro, Jason B; Hovis, Kenneth R; Urban, Nathaniel N (2007) Recurrent dendrodendritic inhibition of accessory olfactory bulb mitral cells requires activation of group I metabotropic glutamate receptors. J Neurosci 27:5664-71
Urban, Nathaniel N; Castro, Jason B (2005) Tuft calcium spikes in accessory olfactory bulb mitral cells. J Neurosci 25:5024-8