Logo image
Back
The impact of a corticotectal impulse on the awake superior colliculus
Journal article   Open access   Peer reviewed

The impact of a corticotectal impulse on the awake superior colliculus

Yulia Bereshpolova, Carl R Stoelzel, Alexander G Gusev, Tatiana Bezdudnaya and Harvey A Swadlow
The Journal of neuroscience, v 26(8), pp 2250-2259
22 Feb 2006
DOI: https://doi.org/10.1523/JNEUROSCI.4402-05.2006
PMID: 16495452
url
https://doi.org/10.1523/JNEUROSCI.4402-05.2006View
Published, Version of Record (VoR) Open

Abstract

Animals Biological Clocks - physiology Evoked Potentials, Visual - physiology Rabbits Superior Colliculi - physiology Visual Cortex - physiology Visual Pathways - physiology Wakefulness - physiology
Corticotectal (CTect) neurons of layer 5 are large and prominent elements of mammalian visual cortex, with thick apical dendrites that ascend to layer 1, "intrinsically bursting" membrane properties, and fast-conducting descending axons that terminate in multiple subcortical domains. These neurons comprise a major output pathway of primary visual cortex, but virtually nothing is known about the synaptic influence of single CTect impulses on the superior colliculus (SC). Here, we examine the distribution of monosynaptic currents generated in the superficial SC by spontaneous impulses of single CTect neurons. We do this by recording the spikes of CTect neurons and the field potentials that they generate through the depths of the SC. Methods of spike-triggered averaging and current source density analysis are then applied to these data. We show, in fully awake rabbits, that single CTect impulses generate potent, fast-rising monosynaptic currents in the SC similar to those generated in sensory cortex by specific thalamic afferents. These currents are focal in depth, precisely retinotopic, and highly dependent on the conduction velocity of the CTect axon. Moreover, we show that CTect synapses, like thalamocortical synapses, suffer a chronic state of depression in awake subjects that is modulated by preceding interspike interval. However, CTect neurons generated few "bursts," and postsynaptic responses in the SC were not significantly influenced by a shift from alert to an inattentive state (indicated by hippocampal EEG). Together, our results suggest that single CTect neurons may resemble thalamocortical neurons in their ability to serve as potent "drivers" of postsynaptic targets.

Metrics

6 Record Views
27 citations in Web of Science
27 citations in Scopus

Details

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Web of Science research areas
Neurosciences
Logo image