Encoding of odor information and reward anticipation in anterior cortical amygdaloid nucleus

Abstract

Olfactory information directly reaches the amygdala through the olfactory cortex, without the involvement of thalamic areas, unlike other sensory systems. The anterior cortical amygdaloid nucleus (ACo) is one of the olfactory cortices that receives olfactory sensory input, and is part of the olfactory cortical amygdala, which relays olfactory information to the amygdala. To examine its electrophysiological features, we recorded individual ACo neurons during the odor-guided go/no-go task to obtain a water reward. Many ACo neurons exhibited odor-evoked go cue-preferred during the late phase of odor-sampling supporting the population dynamics that differentiate go/no-go responses before executing the odor-evoked behaviors. We observed two types of neurons with different anticipation signals: one neuron type exhibited gradual increases of activity toward reward delivery, while another type exhibited a phasic go cue-preferred activity during odor sampling as well as another phasic anticipatory activity for rewards. These results suggest that the ACo may be involved in reward-related behavioral learning by associating the olfactory information with reward anticipation.

Mapping functional traces of opioid memories in the rat brain

“…When morphine and saline-associated contexts are presented to the animals, a circuit formed by the amygdalás cortical and subcortical divisions, the habenula and septum presents itself as a central hub for contextual discrimination. Connectivity changes between the anterior cortical amygdaloid nucleus (ACo), a region seemingly involved in odor-guided reward anticipation (Shiotani et al, 2020), and the LSI, via opposed signal correlated activity in morphine- and saline-paired contexts, are consistent with the lateral septum playing the role of a reward effect modulator (or lever), during the encoding of relevant contextual cues. The central amygdala (CeA) and LHb also exhibit such opposed correlation dichotomy between morphine- and saline-paired contexts.…”