Effect of Brn-3a deficiency on primary nociceptors in the trigeminal ganglion.

Abstract

Immunohistochemistry for substance P, somatostatin and vanilloid receptor subtype 1 as well as receptors for somatostatin and opioids was performed on the trigeminal ganglion in wild-type and Brn-3a knockout mice at postnatal day 0. In wild-type mice, the trigeminal ganglion contained abundant substance P-, vanilloid receptor subtype 1-, sst2A receptor- and delta-opioid receptor-immunoreactive neurons, while the ganglion had only a few mu-opioid receptor-immunoreactive neurons. The Brn-3a deficiency had an effect on the cell size but not the number of substance P-immunoreactive neurons. In knockout mice, the proportion of small immunoreactive neurons markedly increased and that of medium- to large-sized immunoreactive ones correspondingly decreased (mean +/- S.D. = 54.7 +/- 29.1 microm2, range = 10.9-220.8 microm2) compared to wild-type mice (mean +/- S.D. = 116.6 +/- 58.6 microm2, range = 27.3-400.7 microm2). As for vanilloid receptor subtype 1-immunoreactive neurons, the number and cell size was barely affected by the deficiency. On the other hand, the loss of Brn-3a caused a decrease in the number of sst2A receptor- or delta-opioid receptor-immunoreactive neurons (more than 95% reduction) and an increase in the number of mu-opioid receptor-immunoreactive neurons (9.3-fold increase). Somatostatin-immunoreactive neurons were not detected in the trigeminal ganglion of wild-type or mutant mice at postnatal day 0. The present study suggests that Brn-3a deficiency may have effects on the survival of trigeminal nociceptors and their expression of some neurochemical substances.

• Authors: H Ichikawa, S Schulz, V Höllt, Z Mo, M Xiang, T Sugimoto
• Journal: Neuroscience research (Neurosci Res) Vol. 51 Issue 4 Pg. 445-51 (Apr 2005) ISSN: 0168-0102 [Print] Ireland
• PMID: 15740807 (Publication Type: Journal Article)

Chemical References

• DNA-Binding Proteins
• Pou4f1 protein, mouse
• Receptors, Drug
• Receptors, Neurokinin-1
• Receptors, Opioid
• Receptors, Somatostatin
• TRPV Cation Channels
• TRPV1 receptor
• Transcription Factor Brn-3
• Transcription Factor Brn-3A
• Transcription Factors

Topics

• Animals
• Cell Count
• Cell Size
• DNA-Binding Proteins (deficiency)
• Immunohistochemistry
• Mice
• Mice, Knockout
• Neurons (metabolism)
• Nociceptors (metabolism)
• Receptors, Drug (metabolism)
• Receptors, Neurokinin-1 (metabolism)
• Receptors, Opioid (metabolism)
• Receptors, Somatostatin (metabolism)
• TRPV Cation Channels
• Transcription Factor Brn-3
• Transcription Factor Brn-3A
• Transcription Factors (deficiency)
• Trigeminal Ganglion (metabolism)