(Open access funding provided by Semmelweis University)
(2017-1.2.1-NKP-2017-00002.)
(Gedeon Richter Plc.)
The human mu rhythm has been suggested to represent an important function in information
processing. Rodent homologue rhythms have been assumed though no study has investigated
them from the cognitive aspect yet. As voluntary goal-directed movements induce the
desynchronization of mu rhythm, we aimed at exploring whether the response-related
brain activity during the touchscreen visual discrimination (VD) task is suitable
to detect sensorimotor rhythms and their change under cognitive impairment. Different
doses of scopolamine or MK-801 were injected subcutaneously to rats, and epidural
electroencephalogram (EEG) was recorded during task performance. Arciform ~ 10 Hz
oscillations appeared during visual processing, then two characteristic alpha/beta
desynchronization-resynchronization patterns emerged mainly above the sensorimotor
areas, serving presumably different motor functions. Beyond causing cognitive impairment,
both drugs supressed the touch-related upper alpha (10-15 Hz) reactivity for desynchronization.
Reaction time predominantly correlated positively with movement-related alpha and
beta power both in normal and impaired conditions. These results support the existence
of a mu homologue rodent rhythm whose upper alpha component appeared to be modulated
by cholinergic and glutamatergic mechanisms and its power change might indicate a
potential EEG correlate of processing speed. The VD task can be utilized for the investigation
of sensorimotor rhythms in rats.
