title: The role of neuron numbers of the petrosal ganglion in the determination of blood pressure: an experimental study.
abstract: BACKGROUND
  Baroreceptor reflexes are regulated by nerve terminals of the glossopharyngeal and vagal nerves. The body of pressure-sensitive neurons of these nerves is located in the petrosal ganglion of both nerves. We examined whether there is a relationship between the neuron numbers of the inferior ganglion of the glossopharyngeal nerve and blood pressure values.
  
  
  METHODS
  Petrosal ganglions were examined in 18 male hybrid rabbits divided into three equal groups: Group A normotensive (TA=90-100 mmHg), Group B hypertensive (TA>100 mmHg); and Group C hypotensive (TA<90 mmHg). After examination of blood pressure for one week, all animals were sacrificed, and the petrosal ganglions extracted bilaterally and examined histopathologically using the physical dissector method.
  
  
  RESULTS
  The mean (+/-SD) neuronal density was: Group A 8700+/-200, Group B 7800+/-250 and Group C 9800+/-300, respectively. The difference between the groups B and C as compared to A was significant (p<0.01) while the difference between Groups B and C was highly significant (p<0.001).
  
  
  CONCLUSIONS
  An inverse relationship was noticed between the neuronal density in the petrosal ganglion and blood pressure values with potential implications in the study of the etiology of hypertension.
authors.affiliation: Department of Neurosurgery, Medical Faculty, Ataturk University, Erzurum, Turkey. nmda11@hotmail.com
authors.forename: M D
authors.initials: MD
authors.lastname: Aydin
authors.forename: E
authors.initials: E
authors.lastname: Bayram
authors.forename: C
authors.initials: C
authors.lastname: Atalay
authors.forename: N
authors.initials: N
authors.lastname: Aydin
authors.forename: A R
authors.initials: AR
authors.lastname: Erdogan
authors.forename: C
authors.initials: C
authors.lastname: Gundogdu
authors.forename: S
authors.initials: S
authors.lastname: Diyarbakirli
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D001933:Brain Stem / Q000473:pathology; D002452:Cell Count; D005930:Glossopharyngeal Nerve / Q000473:pathology*; D006973:Hypertension / Q000473:pathology; D007022:Hypotension / Q000473:pathology; D008297:Male; D009411:Nerve Endings / Q000473:pathology; D009475:Neurons, Afferent / Q000473:pathology; D011311:Pressoreceptors / Q000473:pathology; D011817:Rabbits; D017552:Solitary Nucleus / Q000473:pathology; D014630:Vagus Nerve / Q000473:pathology