PT  - JOURNAL ARTICLE
AU  - L Bleazard
AU  - RG Hill
AU  - R Morris
TI  - The correlation between the distribution of the NK1 receptor and the actions of tachykinin agonists in the dorsal horn of the rat indicates that substance P does not have a functional role on substantia gelatinosa (lamina II) neurons
AID  - 10.1523/JNEUROSCI.14-12-07655.1994
DP  - 1994 Dec 01
TA  - The Journal of Neuroscience
PG  - 7655--7664
VI  - 14
IP  - 12
4099  - http://www.jneurosci.org/content/14/12/7655.short
4100  - http://www.jneurosci.org/content/14/12/7655.full
SO  - J. Neurosci.1994 Dec 01; 14
AB  - The presence of substance P in primary afferents that terminate in the outer laminae of the spinal cord has led to considerable interest in the function of this neuropeptide in nociception. We have examined the actions of tachykinin agonists on the membrane potential of neurons in lamina II of a neonatal spinal cord slice preparation in vitro. Only 10.5% (n = 75) of these neurons showed any response to the application of a selective NK1 receptor agonist while 48.3% (n = 60) of neurons in deeper dorsal horn laminae responded to this agonist. Lamina II neurons were equally insensitive to selective NK2 and NK3 agonists. Synaptic potentials evoked in lamina II neurons by peripheral nerve stimulation were similarly not altered by the NK1 agonist. Immunocytochemical studies using an antibody raised against the C-terminal of the NK1 receptor revealed that very few lamina II neurons express NK1 receptors, and this offers an explanation for our findings.