Year: 2012
Type: dissertation
Abstract: Theta (6-12 Hz) rhythmicity in the local field potential (LFP) and neuronal discharge reflect a clocking mechanism that brings physically isolated neurons together in time, allowing for the integration and segregation of distributed cell assemblies. Variation in the theta signal has been linked to locomotor speed, sensorimotor integration as well as cognitive processing. Mechanistically, variation in the LFP signal results from variation in the synaptic input impinging upon neuronal elements as well as intrinsic membrane oscillations consequent to synaptic input. Previously, we have characterized the relationship between locomotor speed and theta power and how that relationship varies across the septotemporal (long) axis of the hippocampus. The current study investigated the relationship between acceleration (positive acceleration) and deceleration (negative acceleration) and theta indices at CA1 and dentate gyrus (DG) sites along the septotemporal axis of the HPC. Our findings demonstrate that acceleration and deceleration predict a significant amount of the variability in the theta signal. We also demonstrate that deceleration is more predictive of variation in theta amplitude as compared to acceleration as rats traverse a linear track. Further, while the relationship between deceleration and theta power decreased across the long axis, most notably in region CA1, the relationship of acceleration to theta power did not vary across the long axis. Such findings highlight key variables that can be systematically related to dynamics in the theta
Author: Lauren L. Long
Language: English
Subfield: Cognitive Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W200307626