Tags

Type your tag names separated by a space and hit enter

Nicotinic acetylcholine receptors in the rat and primate nucleus tractus solitarius and on rat and human inferior vagal (nodose) ganglia: evidence from in vivo microdialysis and [125I]alpha-bungarotoxin autoradiography.
Neuroscience 1998; 83(4):1113-22N

Abstract

The nucleus tractus solitarius is a key brain centre involved in the regulation of numerous autonomic functions. The present study has employed in vitro autoradiography and in vivo microdialysis to investigate the presence and function of nicotinic acetylcholine receptors located in the medial nucleus tractus solitarius of the rat. Autoradiography using [125I]alpha-bungarotoxin (0.5 nM) enabled visualization of binding sites on sections of rat and monkey brainstem. Specific binding was highest in the medial nucleus tractus solitarius. The presence of binding sites was also apparent on sections of rat nodose ganglia/vagus nerve and human inferior vagal ganglia. Subsequent to unilateral ligation of the vagus nerve in the rat, an accumulation of binding sites was visualized adjacent to the ligature. Unilateral nodose ganglionectomy in the rat caused an approximate 97% reduction in [125I]alpha-bungarotoxin binding site density in the medial nucleus tractus solitarius from 814 +/- 183 to 27 +/- 2 d.p.m./mm2. Microdialysis results indicated that local administration of nicotine (1 mM) into the nucleus tractus solitarius of the rat resulted in increases of extracellular L-glutamate of 146 +/- 9% of basal levels. This effect was not reproducible following a second stimulation and was also blocked by prior and co-administration of the nicotinic acetylcholine receptor antagonist mecamylamine (100 microM). Extracellular levels of L-aspartate exhibited a similar pattern although results were not significant. Taken together, these results are supportive of the presence of a population of [125I]alpha-bungarotoxin binding sites located presynaptically with respect to vagal afferent terminals in the medial nucleus tractus solitarius of the rat. It is possible that these binding sites are the site of action of locally administered nicotine on extracellular levels of L-glutamate, the favoured neurotransmitter at primary baroreceptor afferent fibres. These data are discussed in relation to the functional pharmacology of acetylcholine and nicotinic acetylcholine receptors in this region of the brain.

Authors+Show Affiliations

Department of Pharmacology, Monash University, Clayton, Victoria, Australia.No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9502250

Citation

Ashworth-Preece, M, et al. "Nicotinic Acetylcholine Receptors in the Rat and Primate Nucleus Tractus Solitarius and On Rat and Human Inferior Vagal (nodose) Ganglia: Evidence From in Vivo Microdialysis and [125I]alpha-bungarotoxin Autoradiography." Neuroscience, vol. 83, no. 4, 1998, pp. 1113-22.
Ashworth-Preece M, Jarrott B, Lawrence AJ. Nicotinic acetylcholine receptors in the rat and primate nucleus tractus solitarius and on rat and human inferior vagal (nodose) ganglia: evidence from in vivo microdialysis and [125I]alpha-bungarotoxin autoradiography. Neuroscience. 1998;83(4):1113-22.
Ashworth-Preece, M., Jarrott, B., & Lawrence, A. J. (1998). Nicotinic acetylcholine receptors in the rat and primate nucleus tractus solitarius and on rat and human inferior vagal (nodose) ganglia: evidence from in vivo microdialysis and [125I]alpha-bungarotoxin autoradiography. Neuroscience, 83(4), pp. 1113-22.
Ashworth-Preece M, Jarrott B, Lawrence AJ. Nicotinic Acetylcholine Receptors in the Rat and Primate Nucleus Tractus Solitarius and On Rat and Human Inferior Vagal (nodose) Ganglia: Evidence From in Vivo Microdialysis and [125I]alpha-bungarotoxin Autoradiography. Neuroscience. 1998;83(4):1113-22. PubMed PMID: 9502250.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Nicotinic acetylcholine receptors in the rat and primate nucleus tractus solitarius and on rat and human inferior vagal (nodose) ganglia: evidence from in vivo microdialysis and [125I]alpha-bungarotoxin autoradiography. AU - Ashworth-Preece,M, AU - Jarrott,B, AU - Lawrence,A J, PY - 1998/3/21/pubmed PY - 1998/3/21/medline PY - 1998/3/21/entrez SP - 1113 EP - 22 JF - Neuroscience JO - Neuroscience VL - 83 IS - 4 N2 - The nucleus tractus solitarius is a key brain centre involved in the regulation of numerous autonomic functions. The present study has employed in vitro autoradiography and in vivo microdialysis to investigate the presence and function of nicotinic acetylcholine receptors located in the medial nucleus tractus solitarius of the rat. Autoradiography using [125I]alpha-bungarotoxin (0.5 nM) enabled visualization of binding sites on sections of rat and monkey brainstem. Specific binding was highest in the medial nucleus tractus solitarius. The presence of binding sites was also apparent on sections of rat nodose ganglia/vagus nerve and human inferior vagal ganglia. Subsequent to unilateral ligation of the vagus nerve in the rat, an accumulation of binding sites was visualized adjacent to the ligature. Unilateral nodose ganglionectomy in the rat caused an approximate 97% reduction in [125I]alpha-bungarotoxin binding site density in the medial nucleus tractus solitarius from 814 +/- 183 to 27 +/- 2 d.p.m./mm2. Microdialysis results indicated that local administration of nicotine (1 mM) into the nucleus tractus solitarius of the rat resulted in increases of extracellular L-glutamate of 146 +/- 9% of basal levels. This effect was not reproducible following a second stimulation and was also blocked by prior and co-administration of the nicotinic acetylcholine receptor antagonist mecamylamine (100 microM). Extracellular levels of L-aspartate exhibited a similar pattern although results were not significant. Taken together, these results are supportive of the presence of a population of [125I]alpha-bungarotoxin binding sites located presynaptically with respect to vagal afferent terminals in the medial nucleus tractus solitarius of the rat. It is possible that these binding sites are the site of action of locally administered nicotine on extracellular levels of L-glutamate, the favoured neurotransmitter at primary baroreceptor afferent fibres. These data are discussed in relation to the functional pharmacology of acetylcholine and nicotinic acetylcholine receptors in this region of the brain. SN - 0306-4522 UR - https://www.unboundmedicine.com/medline/citation/9502250/Nicotinic_acetylcholine_receptors_in_the_rat_and_primate_nucleus_tractus_solitarius_and_on_rat_and_human_inferior_vagal__nodose__ganglia:_evidence_from_in_vivo_microdialysis_and_[125I]alpha_bungarotoxin_autoradiography_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0306452297004764 DB - PRIME DP - Unbound Medicine ER -