TY - JOUR
T1 - Effects of caloric restriction on monoaminergic neurotransmission, peripheral hormones, and olfactory memory in aged rats
AU - Rojic-Becker, Divka
AU - Portero-Tresserra, Marta
AU - Martí-Nicolovius, Margarita
AU - Vale-Martínez, Anna
AU - Guillazo-Blanch, Gemma
N1 - Copyright © 2021 Elsevier B.V. All rights reserved.
PY - 2021/7/9
Y1 - 2021/7/9
N2 - Aging is associated with a reduced ability to identify and discriminate scents, and olfactory dysfunction has been linked to preclinical stages of neurodegenerative diseases in humans. Moreover, emerging evidence suggests that smell-driven behaviors are regulated by hormones like insulin or leptin, and by metabolic parameters like glucose, which in turn may influence monoaminergic neurotransmission in brain areas related to cognition. Several studies have suggested that dietary interventions like caloric restriction (CR) can mitigate the age-induced decline in memory by modifying metabolic parameters and brain monoaminergic levels. The present study explored the effects of CR on age-dependent olfactory memory deficits, as well as their relationship with peripheral leptin, insulin and glucose levels, and brain monoamines. To this end, aged rats (24-months-old) fed on a CR diet or with ad libitum access to food, and adult rats (3–4 months), were trained in an odor discrimination task (ODT). The peripheral plasma levels of insulin, leptin, and glucose, and of monoamines and metabolites/precursors in brain areas related to olfactory learning and memory processes, such as the striatum and frontal cortex (FC), were determined. The data obtained indicated that CR attenuated the age-dependent decline in olfactory sensitivity in old animals fed ad libitum, which was correlated with the performance in ODT retention trial, as well as with leptin plasma levels. CR enhanced dopamine levels in the striatum, while it attenuated the age-related decline in serotonin levels in the striatum and FC. Such findings support a positive effect of CR on age-dependent olfactory sensitivity decline and dysfunctions in brain monoamine levels.
AB - Aging is associated with a reduced ability to identify and discriminate scents, and olfactory dysfunction has been linked to preclinical stages of neurodegenerative diseases in humans. Moreover, emerging evidence suggests that smell-driven behaviors are regulated by hormones like insulin or leptin, and by metabolic parameters like glucose, which in turn may influence monoaminergic neurotransmission in brain areas related to cognition. Several studies have suggested that dietary interventions like caloric restriction (CR) can mitigate the age-induced decline in memory by modifying metabolic parameters and brain monoaminergic levels. The present study explored the effects of CR on age-dependent olfactory memory deficits, as well as their relationship with peripheral leptin, insulin and glucose levels, and brain monoamines. To this end, aged rats (24-months-old) fed on a CR diet or with ad libitum access to food, and adult rats (3–4 months), were trained in an odor discrimination task (ODT). The peripheral plasma levels of insulin, leptin, and glucose, and of monoamines and metabolites/precursors in brain areas related to olfactory learning and memory processes, such as the striatum and frontal cortex (FC), were determined. The data obtained indicated that CR attenuated the age-dependent decline in olfactory sensitivity in old animals fed ad libitum, which was correlated with the performance in ODT retention trial, as well as with leptin plasma levels. CR enhanced dopamine levels in the striatum, while it attenuated the age-related decline in serotonin levels in the striatum and FC. Such findings support a positive effect of CR on age-dependent olfactory sensitivity decline and dysfunctions in brain monoamine levels.
KW - Aging
KW - Frontal cortex
KW - IGF-1
KW - Leptin
KW - Odor-reward association
KW - Striatum
UR - http://www.scopus.com/inward/record.url?scp=85104932434&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2021.113328
DO - 10.1016/j.bbr.2021.113328
M3 - Article
C2 - 33930470
AN - SCOPUS:85104932434
SN - 0166-4328
VL - 409
JO - Behavioural Brain Research
JF - Behavioural Brain Research
M1 - 113328
ER -