title: Interactive responses of a thalamic neuron to formalin induced lasting pain in behaving mice.
abstract: Thalamocortical (TC) neurons are known to relay incoming sensory information to the cortex via firing in tonic or burst mode. However, it is still unclear how respective firing modes of a single thalamic relay neuron contribute to pain perception under consciousness. Some studies report that bursting could increase pain in hyperalgesic conditions while others suggest the contrary. However, since previous studies were done under either neuropathic pain conditions or often under anesthesia, the mechanism of thalamic pain modulation under awake conditions is not well understood. We therefore characterized the thalamic firing patterns of behaving mice in response to nociceptive pain induced by inflammation. Our results demonstrated that nociceptive pain responses were positively correlated with tonic firing and negatively correlated with burst firing of individual TC neurons. Furthermore, burst properties such as intra-burst-interval (IntraBI) also turned out to be reliably correlated with the changes of nociceptive pain responses. In addition, brain stimulation experiments revealed that only bursts with specific bursting patterns could significantly abolish behavioral nociceptive responses. The results indicate that specific patterns of bursting activity in thalamocortical relay neurons play a critical role in controlling long-lasting inflammatory pain in awake and behaving mice.
authors.affiliation: Center for Neural Science, Korea Institute of Science and Technology, Seoul, Korea.
authors.forename: Yeowool
authors.initials: Y
authors.lastname: Huh
authors.forename: Rushi
authors.initials: R
authors.lastname: Bhatt
authors.forename: DaeHyun
authors.initials: D
authors.lastname: Jung
authors.forename: Hee-sup
authors.initials: HS
authors.lastname: Shin
authors.forename: Jeiwon
authors.initials: J
authors.lastname: Cho
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D002450:Cell Communication / Q000187:drug effects; D059350:Chronic Pain / Q000139:chemically induced* / Q000503:physiopathology*; D055724:Electrophysiological Phenomena / Q000187:drug effects; D005557:Formaldehyde / Q000633:toxicity*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D009474:Neurons / Q000187:drug effects* / Q000502:physiology*; D059225:Nociception / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D013788:Thalamus / Q000166:cytology / Q000187:drug effects* / Q000502:physiology
chemical_list: D005557:Formaldehyde