Spinothalamic lamina I neurons selectively sensitive to histamine: a central neural pathway for itch

@article{Andrew2001SpinothalamicLI,
  title={Spinothalamic lamina I neurons selectively sensitive to histamine: a central neural pathway for itch},
  author={David Andrew and A. D. Craig},
  journal={Nature Neuroscience},
  year={2001},
  volume={4},
  pages={72-77}
}
We found a class of lamina I spinothalamic tract (STT) neurons selectively excited by iontophoretic histamine. The responses of this class of neurons parallel the pure itching sensation this stimulus elicits in humans, and match the responses of peripheral C-fibers that have similar selectivity. These neurons have distinct central conduction velocities and thalamic projections, indicating that they constitute a unique subset of STT neurons. These findings can explain why a lesion of the lateral… 
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References

SHOWING 1-10 OF 38 REFERENCES
Nociceptive and thermoreceptive lamina I neurons are anatomically distinct
TLDR
The results support the view that central pain and temperature pathways contain anatomically discrete sets of modality-selective neurons.
Itching for an explanation
Superficial dorsal horn neurons identified by intracutaneous histamine: chemonociceptive responses and modulation by morphine.
TLDR
The results indicate that superficial dorsal horn neurons respond to both pruritic and algesic chemical stimuli and thus might participate in transmitting sensations of itch and/or chemogenic pain.
Responses of rat spinal dorsal horn neurons to intracutaneous microinjection of histamine, capsaicin, and other irritants.
  • E. Carstens
  • Biology, Medicine
    Journal of neurophysiology
  • 1997
TLDR
To investigate the spinal processing of cutaneous pruritic and algesic stimuli, single-unit recordings were made from wide-dynamic-range-type lumbar spinal dorsal horn neurons in pentobarbital-sodium-anesthetized rats to reconcile psychophysical and clinical observations of pain and itch sensation.
Morphological classes of spinothalamic lamina I neurons in the cat
TLDR
The morphology and distribution of retrogradely labeled spinothalamic tract neurons in lamina I of the spinal dorsal horn after large injections of cholera toxin subunit B (CTb) or Fast Blue into the contralateral thalamus of cats is examined.
Novel classes of responsive and unresponsive C nociceptors in human skin
TLDR
Novel classes of C nociceptors in human skin are reported, namely, units responding only to mechanical stimuli (CM), units respondingonly to heating (CH), and units that were insensitive to mechanical and heating stimuli and also to sympathetic provocation tests (CMiHi).
...
...