[Abstract Title]. - Society for Neuroscience

Society for Neuroscience Abstracts, 2007). In that work, we assumed the classical and
modulatory inputs were co-distributed in the dendrites. In the current work, we discarded this
assumption based on recent evidence from modeling and experimental studies of layer 5
pyramidal cells showing that nonlinear "summation" of two inputs to the basal dendrites depends
strongly on their absolute and relative locations (Behabadi et al., Society for Neuroscience
Abstracts, 2007). We found that "scaling competence" was significantly improved when the
modulatory input was delivered to the proximal portion of the dendritic branch. In that case, an
accurate and repeatable multiplicative scaling of the classical response could be achieved over
multiple octaves of input and output dynamic range. This finding supports the proposal of
Behabadi et al. (2007) that attentional, contextual and other scaling inputs may target more
proximal regions of neocortical basal dendrites. This work was supported by NIMH grant
MH065918-01.
Disclosures: M. Jadi , None; B.W. Mel, None.
Poster
240. Intrinsic Membrane Properties: Modulation of Neuronal Firing Properties by Inputs
and Activity
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 240.2/E24
Topic: B.10.b. Modulation of neuronal firing properties
Support: NIH grant NS045248
Title: Electrophysiological characterization of sympathetic preganglionic neurons in HB9-GFP
transgenic mice
Authors: *A. L. ZIMMERMAN 1 , S. HOCHMAN 1,2 ;
1 Biomed. Engin., Georgia Tech/Emory Univ., Atlanta, GA; 2 Physiol., Emory Univ., Atlanta, GA
Abstract: Spinal cord sympathetic preganglionic neurons (SPNs) are the final common output of
the sympathetic nervous system. Intracellular recordings have characterized several
electrophysiological properties of SPNs in rat and cat, and here we extend these studies to
mouse. We undertook whole-cell recordings of fluorescently-identified GFP + -HB9 SPNs in the
intermediolateral column in young mice using horizontal and transverse slices.
Preliminary results using a combination of current and voltage step protocols suggest that the
active and passive membrane properties are comparable to those reported in neonatal rat. Action
potentials exhibited the characteristic inflection during repolarization and prolonged
afterhyperpolarization typical of SPNs (Pickering et al, Neuroscience Letters, 1991. 130: 237-