Functional properties of nociceptive neurons in the nucleus centralis lateralis of the cat thalamus.
We studied functional properties of nociceptive neurons in the thalamic intralaminar nuclei, especially the nucleus centralis lateralis (CL) in urethane-chloralose anesthetized cats. Nociceptive neurons were found in the intralaminar nuclei, i.e. CL, nucleus centralis medialis (CeM) and nucleus parafascicularis (Pf). One third of these nociceptive neurons had their receptive fields throughout the body, including the orofacial area. Namely, they received convergent nociceptive input from the trigeminal and spinal nerve territories. These neurons with widely complex receptive fields were similar to those we found in the middle third of the caudal bulbar reticular formation (RF). Electrical stimulation of the CL antidromically activated about half of the caudal bulbar RF neurons tested. Furthermore, electrical stimulation of the cingulate gyrus antidromically activated some of CL neurons. These findings suggest that most of the CL neurons receiving nociceptive input from throughout the body receive information directly or indirectly via the caudal bulbar RF, and that certain of this information is then conveyed to the cingulate gyrus.
Nishikawa
Y
Y
Department of Physiology, Osaka Dental University, Japan.
Yoshimoto
H
H
Mori
A
A
Mukunoki
S
S
Kakudo
K
K
Yoshida
Y
Y
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D002415:Cats; D003782:Dental Pulp / Q000294:innervation; D004558:Electric Stimulation; D005157:Facial Pain / Q000503:physiopathology*; D005727:Ganglia, Spinal / Q000502:physiology; D006179:Gyrus Cinguli / Q000502:physiology; D020646:Intralaminar Thalamic Nuclei / Q000166:cytology* / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D012154:Reticular Formation / Q000502:physiology; D013133:Spinothalamic Tracts / Q000502:physiology; D012668:Trigeminal Ganglion / Q000502:physiology