Publication: Expression of inhibitory neurotransmitter gabaa receptors in human dental pulp: a potential role in dental nociceptive signalling
Date
2023-08
Authors
Sivakumar, Diveyaa
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Abstract
Dental pain is a prevalent and distressing condition that can have a significant
impact on a person's daily life. It can arise from various causes, including dental
diseases and conditions, as well as during dental treatments. Development of effective
pain management strategies in the dental setting remains a challenge due to the unclear
mechanisms of pain signalling in the dental pulp. Gamma-aminobutyric acid (GABA)
is the main inhibitory neurotransmitter in the mammalian central nervous system
(CNS) and has a well-established role in pain signalling. While several studies have
explored the expression GABA and its receptors in the dental pulp, the exact influence
of these receptors on dental pain signalling is still not fully understood. Therefore, this
study aimed to investigate the gene and protein expression of the two most abundantly
expressed GABAA receptor subunits, α1 and β2, in the healthy human dental pulp. In
order to achieve the objective of the study, techniques such as RNA isolation, reverse
transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC)
were employed. Prior to performing RT-PCR, the annealing temperature for
amplification of both target genes were found to be 55°C. Gene expression analysis
using RT-PCR demonstrated the presence of GABRA1 and GABRB2 in the dental pulp,
and independent T-test analysis indicated that the expression of GABRA1 was
significantly higher than GABRB2. Immunohistochemical staining provided visual
evidence of GABRA1 and GABRB2 protein expression in the odontoblast layer of
dental pulp, indicating their presence in cell bodies and odontoblastic processes extending into the dentin. Optimal IHC staining results were obtained by using Tris-
EDTA (TE) buffer at pH9 for antigen retrieval with antibody concentrations of 1:50
and 1:200 for the GABRA1 and GABRB2 antibodies, respectively. These findings
support the hypothesis that GABAA receptor α1 and β2 subunits are expressed in
human dental pulp. The presence of gene and protein expression of these subunits
offers valuable insights for further research into the potential roles of GABAA
receptors in dental related pain signalling. Future studies using diseased samples and
functional investigations are warranted to explore the precise mechanisms and
implications of GABAA receptor α1 and β2 subunits in dental pain and their potential
therapeutic applications.