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Influence of Age on Nicotinic Cholinergic Regulation of Blood Flow in Rat's Olfactory Bulb and Neocortex

Overview
Journal J Physiol Sci
Specialty Physiology
Date 2024 Mar 16
PMID 38491428
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Abstract

The olfactory bulb receives cholinergic basal forebrain inputs as does the neocortex. With a focus on nicotinic acetylcholine receptors (nAChRs), this review article provides an overview and discussion of the following findings: (1) the nAChRs-mediated regulation of regional blood flow in the neocortex and olfactory bulb, (2) the nAChR subtypes that mediate their responses, and (3) their activity in old rats. The activation of the α4β2-like subtype of nAChRs produces vasodilation in the neocortex, and potentiates olfactory bulb vasodilation induced by olfactory stimulation. The nAChR activity producing neocortical vasodilation was similarly maintained in 2-year-old rats as in adult rats, but was clearly reduced in 3-year-old rats. In contrast, nAChR activity in the olfactory bulb was reduced already in 2-year-old rats. Thus, age-related impairment of α4β2-like nAChR function may occur earlier in the olfactory bulb than in the neocortex. Given the findings, the vasodilation induced by α4β2-like nAChR activation may be beneficial for neuroprotection in the neocortex and the olfactory bulb.

References
1.
Doty R, Shaman P, Applebaum S, Giberson R, Siksorski L, Rosenberg L . Smell identification ability: changes with age. Science. 1984; 226(4681):1441-3. DOI: 10.1126/science.6505700. View

2.
Tohgi H, Utsugisawa K, Yoshimura M, Nagane Y, Mihara M . Age-related changes in nicotinic acetylcholine receptor subunits alpha4 and beta2 messenger RNA expression in postmortem human frontal cortex and hippocampus. Neurosci Lett. 1998; 245(3):139-42. DOI: 10.1016/s0304-3940(98)00205-5. View

3.
Whitehouse P, Price D, Struble R, CLARK A, Coyle J, Delon M . Alzheimer's disease and senile dementia: loss of neurons in the basal forebrain. Science. 1982; 215(4537):1237-9. DOI: 10.1126/science.7058341. View

4.
Wada E, Wada K, Boulter J, Deneris E, Heinemann S, Patrick J . Distribution of alpha 2, alpha 3, alpha 4, and beta 2 neuronal nicotinic receptor subunit mRNAs in the central nervous system: a hybridization histochemical study in the rat. J Comp Neurol. 1989; 284(2):314-35. DOI: 10.1002/cne.902840212. View

5.
Kimura A, Okada K, Sato A, Suzuki H . Regional cerebral blood flow in the frontal, parietal and occipital cortices increases independently of systemic arterial pressure during slow walking in conscious rats. Neurosci Res. 1994; 20(4):309-15. DOI: 10.1016/0168-0102(94)90052-3. View