Quantitative and Ultrastructural Analysis of Afferent Terminals from Tooth Pulp in the Trigeminal Principal Sensory Nucleus.
- Author:
Hye Kyung NAM
1
;
Karp Shik CHOI
;
Kuk Pil PARK
;
Yong Chul BAE
Author Information
1. Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyungpook National University, Korea.
- Publication Type:Original Article
- Keywords:
Trigeminal principal sensory nucleus;
Afferent terminal;
Tooth pulp;
GABA
- MeSH:
Carisoprodol;
Dendrites;
Dendritic Spines;
gamma-Aminobutyric Acid;
Horseradish Peroxidase;
Immunohistochemistry;
Mitochondrial Size;
Neurotransmitter Agents;
Presynaptic Terminals;
Synaptic Vesicles;
Tooth*;
Triticum
- From:Korean Journal of Anatomy
2002;35(5):439-452
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
To analyze the synaptic characteristics of axon terminals originated from tooth pulp in the trigeminal principal sensory nucleus, and find morphological evidence that p-endings on these terminals use GABA as neurotransmitter, labeling of tooth pulp afferents with wheat -germ agglutinin conjugated horseradish peroxidase, postembedding immunocytochemistry and morphometric analysis were performed. The results obtained were as follows. The labeled boutons contained clear and round synaptic vesicles, and the mean number of synaptic contacts was 4.21 +/- 2.58. The postsynaptic profiles were usually middle or distal dendrites and dendritic spines rather than soma or proximal dendrites. The mean number of synaptic contacts with p -endings was 2.62 +/- 2.01. The volume of labeled bouton was 4.39 +/- 3.08 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.96), total apposed surface area (r = 0.84), total active zone area (r = 0.84), mitochondrial volume (r = 0.95), the number of synaptic vesicles (r = 0.92), the number of synaptic profiles (r = 0.76) and the number of synaptic p -endings (r = 0.67). The p -endings contained pleomorphic synaptic vesicles. The volume of p -ending was 0.91 +/- 0.47 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.94), total apposed surface area (r = 0.76), total active zone area (r = 0.62), mitochondrial volume (r = 0.70) and the number of synaptic vesicles (r = 0.94). P -endings were GABA immunoreactive. These results suggest that tooth pulp afferent terminals in trigeminal principal sensory nucleus may be related to complex processing of sensory information and presynaptic p -endings using GABA as neurotransmitter, are important in this sensory processing. The "size principle" of Pierce and Mendel (1993) is also applicable to tooth pulp afferent terminals and presynaptic p -endings.
