Impairment of the Anterior Thalamic Head Direction Cell Network Following Administration of the NMDA antagonist MK-801.

Impairment of the Anterior Thalamic Head Direction Cell Network Following Administration of the NMDA antagonist MK-801.
Brain Res Bull. 2014 Oct 9;
Authors: Housh AA, Berkowitz LE, Ybarra I, Kim EU, Lee BR, Calton JL
Abstract
Head direction (HD) cells, found in the rodent Papez circuit, are thought to form the neural circuitry responsible for directional orientation. Because NMDA transmission has been implicated in spatial tasks requiring directional orientation, we sought to determine if the NMDA antagonist dizocilpine (MK-801) would disrupt the directional signal carried by the HD network. Anterior thalamic HD cells were isolated in female Long-Evans rats and initially monitored for baseline directional activity while the animals foraged in a familiar enclosure. The animals were then administered MK-801 at a dose of .05mg/kg or 0.1mg/kg, or isotonic saline, and cells were re-examined for changes in directional specificity and landmark control. While the cells showed no changes in directional specificity and landmark control following administration of saline or the lower dose of MK-801, the higher dose of MK-801 caused a dramatic attenuation of the directional signal, characterized by decreases in peak firing rates, signal to noise, and directional information content. While the greatly attenuated directional specificity of cells in the high dose condition usually remained stable relative to the landmarks within the recording enclo...

Source: Brain Research Bulletin - October 9, 2014 Category: Neurology Authors: Housh AA, Berkowitz LE, Ybarra I, Kim EU, Lee BR, Calton JL Tags: Brain Res Bull Source Type: research