PMID- 3416981
OWN - NLM
STAT- MEDLINE
DCOM- 19881024
LR  - 20191210
IS  - 0014-4886 (Print)
IS  - 0014-4886 (Linking)
VI  - 101
IP  - 3
DP  - 1988 Sep
TI  - Properties of functionally identified nociceptive and nonnociceptive facial 
      primary afferents and presynaptic excitability changes induced in their brain 
      stem endings by raphe and orofacial stimuli in cats.
PG  - 385-99
AB  - The activity of 221 single primary afferent units was recorded extracellularly in 
      the trigeminal (V) ganglion of chloralose-anaesthetized cats to examine the 
      receptive field properties of nonnociceptive and nociceptive cutaneous afferents 
      and the effect of conditioning stimulation of the raphe system and orofacial 
      afferents on the antidromic excitability of their brain stem endings in V 
      subnucleus caudalis. In addition to slowly adapting and rapidly adapting 
      low-threshold mechanosensitive afferents, we functionally identified three 
      classes of cutaneous nociceptive afferents: these included A-delta high-threshold 
      mechanoreceptive afferents (A-delta HTMs), C-fiber high-threshold 
      mechanoreceptive afferents (C-HTMs), and C-polymodal nociceptive afferents 
      (CPNs). Most of the CPNs could be activated by light tactile stimuli as well as 
      by heavy pressure and pinch and noxious radiant heat applied to their 
      mechanoreceptive field which usually involved a localized spot (approximately 1 
      mm in diameter) of skin. In contrast, the C-HTMs and A-delta HTMs could not be 
      activated by radiant heat stimuli although some did show sensitization which was 
      also a feature of the CPNs; they did respond to noxious mechanical stimulation of 
      a localized area of skin. We noted that orofacial conditioning stimulation could 
      produce an increase in antidromic excitability which was considered a reflection 
      of primary afferent depolarization (PAD) in both nociceptive and nonnociceptive 
      afferents innervating the cat's facial skin; nonnoxious mechanical stimuli and 
      electrical stimuli were particularly effective in the low-threshold 
      mechanosensitive afferents and noxious mechanical and high-intensity electrical 
      stimuli were especially effective in the cutaneous nociceptive afferents. Raphe 
      conditioning stimulation also was very effective in inducing PAD in these 
      nociceptive afferents; however, the raphe conditioning effects were not limited 
      to these nociceptive afferents since PAD was also frequently demonstrated in the 
      low-threshold mechanosensitive afferents.
FAU - Hu, J W
AU  - Hu JW
AD  - Faculty of Dentistry, University of Toronto, Canada.
FAU - Sessle, B J
AU  - Sessle BJ
LA  - eng
GR  - DE04786/DE/NIDCR NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Exp Neurol
JT  - Experimental neurology
JID - 0370712
SB  - IM
MH  - Animals
MH  - Brain Stem/*physiology
MH  - Cats
MH  - Conditioning, Psychological/physiology
MH  - Electric Stimulation
MH  - Evoked Potentials
MH  - Facial Nerve/*physiology
MH  - Mechanoreceptors/*physiology
MH  - Nerve Endings/physiology
MH  - Neurons, Afferent/*physiology
MH  - Nociceptors/*physiology
MH  - Raphe Nuclei/*physiology
MH  - Sensory Thresholds
MH  - Skin/innervation
MH  - Synapses/physiology
EDAT- 1988/09/01 00:00
MHDA- 1988/09/01 00:01
CRDT- 1988/09/01 00:00
PHST- 1988/09/01 00:00 [pubmed]
PHST- 1988/09/01 00:01 [medline]
PHST- 1988/09/01 00:00 [entrez]
AID - 10.1016/0014-4886(88)90050-7 [doi]
PST - ppublish
SO  - Exp Neurol. 1988 Sep;101(3):385-99. doi: 10.1016/0014-4886(88)90050-7.