Changes in response modulation of cat perigeniculate neurons related to EEG state and application of neuromodulators.
Spike activity of single perigeniculate (PGN) neurons was recorded in the anaesthetized (N2O/halothane) and paralysed cat during presentation of moving gratings of optimal spatial frequency. Typically, the ongoing (tonic, spontaneous) activity of PGN cells increased during a rise in EEG delta power accompanied by a reduction and often a total loss of spike rate modulation by the moving grating. The opposite behaviour was found when the EEG delta power vanished. Micro-iontophoretically applied acetylcholine (ACh) had an effect similar to a decrease in EEG delta power, decreasing ongoing activity but increasing the response modulation depth. The opposite effect could be achieved with the excitatory action of serotonin (5-HT), mimicking a strengthened EEG delta power. These data support previous data indicating that PGN neurons contribute to spatio-temporal tuning of subcortical visual activity in a state-dependent way.
Department of Neurophysiology, Medical Faculty, Ruhr-University Bochum, Germany.
K
K
Funke
Y
Y
Zhao
U T
UT
Eysel
D000109:Acetylcholine / Q000494:pharmacology*; D000758:Anesthesia; D000818:Animals; D002415:Cats; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D005830:Geniculate Ganglion / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation; D012701:Serotonin / Q000494:pharmacology*; D014795:Visual Pathways / Q000502:physiology*
D012701:Serotonin; D000109:Acetylcholine