Optogenetic dissection of basolateral amygdala contributions to intertemporal choice in young and aged rats

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.

Impairments in fear extinction memory and basolateral amygdala plasticity in the TgF344-AD rat model of Alzheimer’s disease are distinct from non-pathological aging

“…While impaired LTP in the BA of middle-aged WT rats is novel, consistent with our own findings, older age is accompanied by impaired LTP (Zeng et al, 2012;Zhan et al, 2018). These results were not surprising given a wide body of literature showing older adults and rats depend on differential neural recruitment to achieve equal performance (Samanez-Larkin et al, 2011;Antonenko and Flöel, 2014;Lighthall et al, 2014;Tomás Pereira et al, 2015;Wang et al, 2015;Hernandez et al, 2019). Notably, these studies did not incorporate a middle-aged group to determine whether age differences are progressive, abrupt, or dynamic.…”

“…The associations between extinction retrieval and synaptic function in aged WT and all TgAD rats deviate from young WT suggesting any combination of synaptic deficits results in long-term extinction deficits. Although the BLA is a foci for fear memory encoding, consolidation, and storage, other neural circuitry can compensate when BLA deficits are present (Cahill et al, 2000; Maren, 2001; Kochli et al, 2015), particularly in aging (Hernandez et al, 2019).…”

Lateral Orbitofrontal Cortex and Basolateral Amygdala Regulate Sensitivity to Delayed Punishment during Decision-making

“…Thus, BLA inactivation-evoked avoidance of punished rewards is selective for situations with delayed punishment. The reduced delay discounting of punishment after BLA inactivation is consistent with a report that optical BLA inactivation reduced delay discounting of reward (Hernandez et al, 2019), although lesions of BLA increased reward delay discounting (Winstanley, 2004).…”

Advances in understanding meso‐cortico‐limbic‐striatal systems mediating risky reward seeking

“…Optogenetic techniques provide the ability to delineate the function of these epochs by enabling temporally precise control over neuronal excitability. Indeed, recent data have demonstrated that contributions to these distinct task epochs may be dissociable, even within a given brain region (Bercovici et al, 2018;Constantinople, Piet, Bibawi, et al, 2019;Friedman et al, 2015;Hernandez et al, 2019;Li et al, 2019;Orsini et al, 2017;Stopper, Tse, et al, 2014). This complex regulation may have important implications for the implementation of therapeutics designed to improve maladaptive decision making.…”