Andres Camarena

 

arcamare@uci.edu

 

RESEARCH INTERESTS

 

The Effects of a Unilateral Hippocampal Lesion on the Brain Cortical Dynamics

The elucidation of the hippocampal contribution to cortical activity would provide key information for the future development of memory prosthesis devices, which would translate the incoming sensory information into a code conveyed to cortex through a specific pattern of electrical stimulation, mimicking the hippocampal input to cortex.

 

Andres Camarena 1

 

Investigating the Origin of Theta Oscillations in the Posterior Parietal Cortex in Rats

Hippocampal theta rhythm is a strong oscillatory pattern ranging between 4-10 Hz that is associated with motor activity, spatial navigation, and mechanisms involved with learning and memory. The aim of this study was to determine if theta is generated in the posterior parietal cortex (PPC) or if it is volume conducted from the hippocampus or some cortical structure adjacent to PPC where it is frequently recorded. The signature of the oscillatory pattern being locally generated in the cortex is the opposite oscillation polarity at the more superficial, compared to deeper layers. The occurrence of activity in the theta range is most notable the hippocampus, but activity within the theta range has been reported in other cortical and subcortical areas as well. We, therefore, sought to identify and isolate independent theta-generating loci in the neocortex so that we could better understand cortico-hippocampal circuitry.

 

Andres Camarena 2

Representative LFP examples around the point of the polarity reversal  (a-c).

a, The theta recorded from the rowing electrode and from the tip located in the fissure are out of phase. b, There is a phase reversal of theta on the rowing electrode relative to the theta recorded in the fissure. c, The theta recorded from the rowing electrode and from the tip located in the fissure are in phase.