Cortical Communication at the Cellular and Mesoscale Resolution [electronic resource].

9780438970694

Ann Arbor : ProQuest Dissertations & Theses, 2018.

1 online resource (148 p.)

Access is available to the Yale community.

The principles of cortical communication must be studied at multiple spatio-temporal scales. Here I present two studies: "Synaptic Mechanisms of Tight Spike Synchrony at Gamma Frequency in Cerebral Cortex- and "Dissociating? Widespread Cortical Activity During Visual Task Performance". The first is an investigation of high-frequency oscillations, which are ubiquitous in cerebral cortex and implicated in attention. Tight spike synchrony of fast-spiking interneurons is shown to be intimately related to gamma rhythm (30-80 Hz). The mechanism of this spike synchrony is probed with dual whole-cell recordings of either pyramidal or fast-spiking cells in vitro. Both cell types received highly synchronized inhibitory currents. Higher spike synchrony in fast-spiking interneurons was attributed to larger excitatory input synchrony in fast-spiking interneurons compared with pyramidal cells. These findings support the PING model of gamma generation. The second investigation recorded wide-field calcium activity from the dorsal cortex of mice performing a visual detection task. Mice execute a wide range of behaviors and fluctuate their arousal state while head-fixed, complicating interpretation of neural signals. We measured cortical activity while simultaneously recording treadmill speed and video of the pupil. Post-stimulus activity was widespread before the lick response. Secondary motor cortex was highly correlated with licking and was necessary for optimal task performance. Choice probability arose first in secondary motor cortex and spread throughout dorsal cortex before the response. Finally, arousal and eye-movement evoked activity was shown to be partially responsible for higher activity before miss trials compared to hit trials.

Dissertations & Theses @ Yale University.

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English

August 21, 2019

Thesis (Ph.D.)--Yale University, 2018.

Yale University.