Biology subjects

Amaya, K. A.

Publications and source records attributed to Amaya, K. A..

4 recordsLinked to original sources

bioRxiv2024

Habit learning shapes activity dynamics in the central nucleus of the amygdala

As animals perform instrumental tasks, they may develop a habit response with extended experience. Habits are automatic, inflexible, outcome value insensitive behaviors that are regulated by a network of brain regions including the central nucleus of the amygdala (CeA). Prior work has demonstrated that the CeA governs motivational pursuit and is necessary for habit formation. However, the behavioral features that CeA neurons encode in habit formation remain relatively unknown. To address this, we first used male and female Long-Evans rats to quantify CeA cFos expression after performance of a maze task. There, we found that animals with extended training show elevated cFos expression. Then, we implanted animals with drivable silicon probes to record in-vivo single unit electrophysiological activity from the CeA as animals developed habit responding on the maze. We observed significant activity during outcome consumption late in training while also observing elevated unit activity when animals consumed outcomes of larger magnitudes. Outcome related activity did not persist during probe tests following outcome devaluation, despite animals continuing to perform the task. Together, these data add to growing evidence that suggests that the CeA is involved in motivational processes that contribute to the development of habit formation.

neuroscience↗

bioRxiv2023

Basolateral amygdala parvalbumin interneurons coordinate oscillations to drive reward behaviors

The basolateral amygdala (BLA) has been implicated in mediating both fear and reward learning. Parvalbumin interneurons (PVs) in the BLA have previously been shown to contribute to BLA oscillatory states integral to fear expression, but whether BLA oscillatory states and PV interneurons also contribute to reward learning is unknown and critical to our understanding of reward processing. Local field potentials in the BLA were collected as animals consumed a sucrose reward, where prominent changes in the beta band (15-30 Hz) emerged with reward experience. Rhythmic optogenetic stimulation of PV interneurons to entrain the BLA network to 20Hz during consumption of one bottle during a two-bottle choice test produced a robust bottle preference. Finally, to demonstrate that PV activity is necessary for reward value use, PVs were chemogenetically targeted and inhibited following outcome devaluation, rendering those animals incapable of using updated reward value information to guide their behavior. Taken together, these experiments provide novel information regarding the physiological signatures of reward learning while highlighting the importance of PV interneurons in reward learning. This work builds upon the fields established knowledge of PV involvement in fear expression and provides evidence that PV orchestration of unique BLA network states is involved in both learning types.

neuroscience↗

bioRxiv2023

Task history dictates how the dorsolateral striatum controls action strategy and vigor

The dorsolateral striatum (DLS) is linked to the learning and honing of action routines. However, the DLS is also important for performing behaviors that have been successful in the past. The learning function can be thought of as prospective, helping to plan ongoing actions to be efficient and often optimal. The performance function is more retrospective, helping the animal continue to behave in a way that had worked previously. How the DLS manages this all is curious. What happens when a learned behavior becomes sub-optimal due to environment changes. In this case, the prospective function of the DLS would cause animals to (adaptively) learn and plan more optimal actions. In contrast, the retrospective function would cause animals to (maladaptively) favor the old behavior. Here we find that, during a change in learned task rules, DLS inhibition causes animals to adjust less rapidly to the new task (and to behave less vigorously) in a maladaptive way. Yet, when the task is changed back to the initially learned rules, DLS inhibition instead causes a rapid and vigorous adjustment of behavior in an adaptive way. These results show that inhibiting the DLS biases behavior towards initially acquired strategies, implying a more retrospective outlook in action selection when the DLS is offline. Thus, an active DLS could encourage planning and learning action routines more prospectively. Moreover, the DLS control over behavior can appear to be either advantageous/flexible or disadvantageous/inflexible depending on task context, and its control over vigor can change depending on task context. Significant StatementBasal ganglia networks aid behavioral learning (a prospective planning function) but also favor the use of old behaviors (a retrospective performance function), making it unclear what happens when learned behaviors become suboptimal. Here we inhibit the dorsolateral striatum (DLS) as animals encounter a change in task rules, and again when they shift back to those learned task rules. DLS inhibition reduces adjustment to new task rules (and reduces behavioral vigor), but it increases adjustment back to the initially learned task rules later (and increases vigor). Thus, in both cases, DLS inhibition favored the use of the initially learned behavioral strategy, which could appear either maladaptive or adaptive. We suggest that the DLS might promote a prospective orientation of action control.

animal behavior and cognition↗

bioRxiv2022

Nucleus accumbens acetylcholine receptors modulate the balance of flexible and inflexible cue-directed motivation

Sign-tracking is a conditioned response where animals interact with reward-predictive cues and can be used as a means to approximate a cues motivational value. The nucleus accumbens core (NAc) has been highly implicated in mediating the sign-tracking response. Additionally, acetylcholine (ACh) transmission throughout the striatum broadly has been attributed to both incentive motivation and behavioral flexibility. Here, we show that sign-tracking responses are indeed flexible in the face of a contingency change in the form of an omission schedule, and that this flexibility is mediated by NAc ACh. Using behavioral and pharmacological methods, we show that blockade of NAc nicotinic receptors (nAChRs) augmented sign-tracking persistence, while blockade of muscarinic receptors (mAChRs) enhanced response flexibility following introduction of the omission schedule. Further, we detail how mAChR or nAChR antagonism impacted the microstructure of sign-tracking responses. These results indicate that NAc ACh receptors have opposing roles in the regulation of sign-tracking response flexibility without altering the motivational value of the cue.

neuroscience↗