Calyx and dimorphic neurons of mouse Scarpa's ganglion express histamine H3 receptors.
BACKGROUND
Histamine-related drugs are commonly used in the treatment of vertigo and related vestibular disorders. The site of action of these drugs however has not been elucidated yet. Recent works on amphibians showed that histamine H3 receptor antagonists, e.g. betahistine, inhibit the afferent discharge recorded from the vestibular nerve. To assess the expression of H3 histamine receptors in vestibular neurons, we performed mRNA RT-PCR and immunofluorescence experiments in mouse Scarpa's ganglia.


RESULTS
RT-PCR analysis showed the presence of H3 receptor mRNA in mouse ganglia tissue. H3 protein expression was found in vestibular neurons characterized by large and roundish soma, which labeled for calretinin and calbindin.


CONCLUSIONS
The present results are consistent with calyx and dimorphic, but not bouton, afferent vestibular neurons expressing H3 receptors. This study provides a molecular substrate for the effects of histamine-related antivertigo drugs acting on (or binding to) H3 receptors, and suggest a potential target for the treatment of vestibular disorders of peripheral origin.
Tritto
Simona
S
Dipartimento di Fisiologia, Università degli Studi di Pavia, 27100, Italy. simona.tritto@unipv.it
Botta
Laura
L
Zampini
Valeria
V
Zucca
Gianpiero
G
Valli
Paolo
P
Masetto
Sergio
S
D000818:Animals; D001921:Brain / Q000166:cytology; D064032:Calbindin 2; D064026:Calbindins; D002452:Cell Count / Q000379:methods; D048429:Cell Size; D015870:Gene Expression / Q000502:physiology*; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D018100:Receptors, Histamine H3 / Q000235:genetics / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D011984:Sensory Receptor Cells / Q000145:classification* / Q000378:metabolism*; D014725:Vestibular Nerve / Q000166:cytology*
C576511:Calb2 protein, mouse; D064032:Calbindin 2; D064026:Calbindins; D012333:RNA, Messenger; D018100:Receptors, Histamine H3; D064030:S100 Calcium Binding Protein G