Cortical contribution to sensory volleys recorded at thalamic nuclei of lemniscal and paralemniscal pathways.
In order to elucidate the role of cortical input on sensory information processing in different thalamic somatosensory nuclei we recorded potentials evoked (EPs) by whisker deflections of short duration from ventral posteromedial (VPm) and medial posterior (POm) nuclei while manipulating cortico-thalamic activity by means of local cooling, lidocaine application or electrical stimulation. It appeared that only the earliest sub-component of the first negative wave of the EPs resulted from peripheral input, while the rest of the potential's negativity depended on cortical feedback. The latencies and amplitudes of EPs recorded at both nuclei were not significantly different, which might be attributed to urethane anesthesia.
Kublik
Ewa
E
Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland.
Swiejkowski
Daniel A
DA
Wróbel
Andrzej
A
D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004594:Electrophysiology; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D010812:Physical Stimulation; D051381:Rats; D017208:Rats, Wistar; D013696:Temperature; D013787:Thalamic Nuclei / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology