RT Journal Article
SR Electronic
T1 GABA, Not Glutamate, Controls the Activity of Substantia Nigra Reticulata Neurons in Awake, Unrestrained Rats
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6751
OP 6754
DO 10.1523/JNEUROSCI.1528-04.2004
VO 24
IS 30
A1 François Windels
A1 Eugene A. Kiyatkin
YR 2004
UL http://www.jneurosci.org/content/24/30/6751.abstract
AB Substantia nigra pars reticulata (SNr) receives both GABAergic and glutamatergic (GLU) inputs that are believed to act together to regulate neuronal activity in this structure. To examine the role of these inputs, single-unit recording was coupled with iontophoresis of GLU and GABA in rats under two conditions: awake, unrestrained and under chloral hydrate anesthesia. Although GABA potently inhibited SNr cells in both conditions, freely moving rats showed lower sensitivity than anesthetized animals. Likewise, GLU effectively induced excitations in most SNr neurons in anesthetized animals but was much less effective in awake, unrestrained animals in terms of both the number of sensitive cells and the magnitude of GLU-induced excitation. These findings, along with consistent excitations induced by bicuculline in awake, unrestrained rats, suggest that modulation of GABA inhibitory input, not the opposing actions of GLU and GABA, is the primary factor that regulates the activity state of SNr neurons.