CONICET | Buscador de Institutos y Recursos Humanos

Interaction among appetitive and aversive pathways during learning and memory formation in honey bees Martin Klappenbach and Fernando Locatelli Laboratorio de Neurobiología de la Memoria. FCEN-UBA. IFIBYNE-CONICET How appetitive and aversive stimuli are encoded in the brain to induce learning and memory is a relevant question in neuroscience: Insect are useful models to tackle this issue since both kinds of stimuli can be delivered in a discrete way while animals are restrained and prepared for neural recordings. Networks and neurotransmitters involved in appetitive and aversive pathways have started to be revealed. In honey bees and other insects, it was demonstrated that octopamine mediates the appetitive stimulus necessary for appetitive learning, while serotonine and dopamine (DA) mediate the aversive stimuli. In this work we postulate that pure appetitive or aversive experiences do not exist in nature and that action of appetitive and aversive pathways must work coordinated to ensure adaptive behavior. Accordingly we found DA, so far only involved in aversive learning in bees, interferes with the appetitive memory formation and that administration of a DA receptor antagonist produces an enhancement in appetitive memory, revealing the tonic modulation of this amine over the appetitive signaling. It is not known yet at what level from sensory processing to control of motor output this interaction take place. We postulate that this negative modulation is due a downregulation of the sucrose induced signal. This has motivated us to study, by calcium imaging, how DA modulates neural signals in response to sugar and odors at different levels of stimuli processing. As a first step, we observe that DA increases the signal evoked by odor in the antennal lobe (AL), the first relay in the odors´ processing. This could allow animals to enhance perception of an aversive paired odor. In the same way, we hypothesis that DA should decrease the signal evoked by sucrose, providing a neural substrate for the interference observed in the appetitive memory formation. How appetitive and aversive stimuli are encoded in the brain to induce learning and memory is a relevant question in neuroscience: Insect are useful models to tackle this issue since both kinds of stimuli can be delivered in a discrete way while animals are restrained and prepared for neural recordings. Networks and neurotransmitters involved in appetitive and aversive pathways have started to be revealed. In honey bees and other insects, it was demonstrated that octopamine mediates the appetitive stimulus necessary for appetitive learning, while serotonine and dopamine (DA) mediate the aversive stimuli. In this work we postulate that pure appetitive or aversive experiences do not exist in nature and that action of appetitive and aversive pathways must work coordinated to ensure adaptive behavior. Accordingly we found DA, so far only involved in aversive learning in bees, interferes with the appetitive memory formation and that administration of a DA receptor antagonist produces an enhancement in appetitive memory, revealing the tonic modulation of this amine over the appetitive signaling. It is not known yet at what level from sensory processing to control of motor output this interaction take place. We postulate that this negative modulation is due a downregulation of the sucrose induced signal. This has motivated us to study, by calcium imaging, how DA modulates neural signals in response to sugar and odors at different levels of stimuli processing. As a first step, we observe that DA increases the signal evoked by odor in the antennal lobe (AL), the first relay in the odors´ processing. This could allow animals to enhance perception of an aversive paired odor. In the same way, we hypothesis that DA should decrease the signal evoked by sucrose, providing a neural substrate for the interference observed in the appetitive memory formation.