Abstract
Across species, aging is associated with an increased ability to choose delayed over immediate gratification. These experiments used young and aged rats to test the role of the basolateral amygdala (BLA) in intertemporal decision making. An optogenetic approach was used to inactivate the BLA in young and aged rats at discrete time points during choices between levers that yielded a small, immediate vs. a large, delayed food reward. BLA inactivation just prior to decisions attenuated impulsive choice in both young and aged rats. In contrast, inactivation during receipt of the small, immediate reward increased impulsive choice in young rats but had no effect in aged rats. BLA inactivation during the delay or intertrial interval had no effect at either age. These data demonstrate that the BLA plays multiple, temporally distinct roles during intertemporal choice, and show that the contribution of BLA to choice behavior changes across the lifespan.
Highlights
Intertemporal choice refers to decisions between rewards that differ with respect to both their magnitude and how far in the future they will arrive
Virally-transduced basolateral amygdala (BLA) neurons examined in slices from young and aged animals did not differ with respect to input resistance (Young: 122.6 ± 20.7 MW, n = 26 cells; Aged: 120.2 ± 11.6 MW, n = 28 cells; t(52)=0.101, p=0.920), whole cell capacitance (Young: 139.7 ± 7.54 pF, n = 26 cells; Aged: 138.8 ± 6.91 pF, n = 28 cells; t(52)=0.081, p=0.936), or current required to maintain the membrane potential at À70 mV (Young: À104.34 ± 15.9 pA; n = 26 cells; Aged: À116.0 ± 13.3 pA, n = 28 cells; t(52)=0.566, p=0.574)
The trial-by-trial analysis in the current study shows that BLA inactivation during deliberation renders rats more likely to shift their choices to the delayed reward following a choice of the immediate reward, as though the incentive properties
Summary
Intertemporal choice refers to decisions between rewards that differ with respect to both their magnitude and how far in the future they will arrive. Contrary to economic models predicting that older individuals should account for reduced time on the horizon in making intertemporal choices, healthy older adults exhibit a marked increase in preference for delayed outcomes (Green et al, 1996; Green et al, 1999; Jimura et al, 2011; Lockenhoff et al, 2011; Mata et al, 2011; SamanezLarkin et al, 2011; Eppinger et al, 2012) This pattern of choice behavior is sometimes characterized as ‘wisdom’, increased preference for delayed over immediate rewards may be maladaptive. Biases toward delayed gratification in older adults could contribute to inappropriately conservative financial strategies that forgo expenditures necessary to maintain quality of life
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
